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研究论文
Optimizing the carbon coating to eliminate electrochemical interface polarization in a high performance silicon anode for use in a lithium-ion battery
QI Zhi-yan, DAI Li-qin, WANG Zhe-fan, XIE Li-jing, CHEN Jing-peng, CHENG Jia-yao, SONG Ge, LI Xiao-ming, SUN Guo-hua, CHEN Cheng-meng
, doi: 10.1016/S1872-5805(22)60580-8
摘要(47) HTML(25) PDF(10)
摘要:
Ordered and disordered carbons have been commonly used as coating materials for silicon (Si) anodes, however the effect of carbons with different crystallinities and pore structures on their electrochemical performance remains controversial. We used pitch and phenolic resin (PR) as the precursors of ordered and disordered carbon, respectively, to prepare carbon-coated silicon (Si@C) with strictly controlled carbon contents and surface functional groups. Their electrochemical behavior was investigated. An ordered crystalline structure is favorable for electron transport, and mesopores and macropores are conducive to the diffusion of lithium ions. Such a coating with a small pore volume is an excellent buffer for the expansion of Si, and the electrode maintains structural integrity for 50 cycles. A disordered porous structure is less robust and produces a large polarization, which produces continuous volume expansion with cycling and leads to inferior electrochemical performance. As a result, the capacity and capacity retention after 100 cycles at 0.5 A g−1 of Si@C-Pitch are respectively 8 times and 1.9 times those of Si@C-PR. This study provides theoretical guidance for the selection of carbon materials used in Si@C anodes. Ordered and disordered carbons have been commonly used as coating materials for silicon (Si) anodes, however the effect of carbons with different crystallinities and pore structures on their electrochemical performance remains controversial. We used pitch and phenolic resin (PR) as the precursors of ordered and disordered carbon, respectively, to prepare carbon-coated silicon (Si@C) with strictly controlled carbon contents and surface functional groups. Their electrochemical behavior was investigated. An ordered crystalline structure is favorable for electron transport, and mesopores and macropores are conducive to the diffusion of lithium ions. Such a coating with a small pore volume is an excellent buffer for the expansion of Si, and the electrode maintains structural integrity for 50 cycles. A disordered porous structure is less robust and produces a large polarization, which produces continuous volume expansion with cycling and leads to inferior electrochemical performance. As a result, the capacity and capacity retention after 100 cycles at 0.5 A g−1 of Si@C-Pitch are respectively 8 times and 1.9 times those of Si@C-PR. This study provides theoretical guidance for the selection of carbon materials used in Si@C anodes.
金属有机框架复合酚醛树脂基整体式亲水炭应用于空气水捕集
唐宋元, 王永胜, 原亚飞, 巴雅琪, 王立秋, 郝广平, 陆安慧
, doi: 10.1016/S1872-5805(22)60576-6
摘要(83) HTML(50) PDF(26)
摘要:
针对全球水资源短缺的问题,空气水捕集被认为是潜在的解决方案。吸附法空气水捕集技术具有装置结构简单、能量效率高、适用范围广等优点,受到广泛关注,其关键在于高性能多孔吸附剂的开发。多孔炭材料具有孔结构丰富、制备成本低等优点。但是常见炭材料的表面疏水,对于低浓度水汽吸附效果不显著。基于此,本文采用局部亲水强化的策略,通过在酚醛树脂交联骨架中穿插引入可衍生为极性位点的金属有机框架炭前驱体,制备了具有强亲水性的整体式多孔炭。进一步将其应用于“三明治”式空气水捕集装置,在40%~80%相对湿度环境中,吸附剂的水汽捕集质量分数可达约20%。这一调控策略也为制备整体式亲水炭材料应用于其他领域提供了新思路。 针对全球水资源短缺的问题,空气水捕集被认为是潜在的解决方案。吸附法空气水捕集技术具有装置结构简单、能量效率高、适用范围广等优点,受到广泛关注,其关键在于高性能多孔吸附剂的开发。多孔炭材料具有孔结构丰富、制备成本低等优点。但是常见炭材料的表面疏水,对于低浓度水汽吸附效果不显著。基于此,本文采用局部亲水强化的策略,通过在酚醛树脂交联骨架中穿插引入可衍生为极性位点的金属有机框架炭前驱体,制备了具有强亲水性的整体式多孔炭。进一步将其应用于“三明治”式空气水捕集装置,在40%~80%相对湿度环境中,吸附剂的水汽捕集质量分数可达约20%。这一调控策略也为制备整体式亲水炭材料应用于其他领域提供了新思路。
Glycine-derived nitrogen-doped ordered mesoporous carbons with bimodal mesopores for supercapacitor and oxygen reduction
SHAO Ying, HU Ze-yu, YAO Yan, WEI Xiang-ru, GAO Xing-min, WU Zhang-xiong
, doi: 10.1016/S1872-5805(22)60585-7
摘要(34) HTML(17) PDF(10)
摘要:
Nitrogen-doped carbon materials are promising for electrochemical energy storage and conversion. Dopant control and pore engineering play important roles in improving their performance. This work demonstrates the synthesis of nitrogen-doped ordered mesoporous carbons (N-OMCs) with bimodal mesopores using the facile solvent-free nanocasting method. The simplest amino acid (glycine, Gly) is adopted as the sole precursor and the ordered mesoporous silica SBA-15 as the hard template. The confined pyrolysis of Gly in SBA-15 leads to efficient carbonization and nitrogen doping and interesting structuration. The N-OMCs possess high surface areas (923–1374 m2·g−1), large pore volumes (1.32–2.21 cm3·g−1), bimodal mesopores (4.8 and 6.2–20 nm) and high nitrogen contents (3.66%–12.23%). The effects of Gly/SBA-15 mass ratio (1–3) and temperature (700–1000 °C) on the physicochemical properties of the N-OMCs are studied. The N-OMCs as electrode materials possess high performance in supercapacitor. The typical sample shows a large specific capacitance of 298 F·g−1, a good rate capability (70 % retention at 30 A·g−1) and a high stability. The different capacitance and rate capability of the N-OMCs are discussed by correlating with their physicochemical properties. The balance of surface area, graphitization, and nitrogen doping and open mesoporous structure is essential to achieve the best performance. The O-NMCs also show good performance in electrocatalytic oxygen reduction reaction (ORR). The typical sample shows high onset and half-wave potentials of 0.92 and 0.83 V and a large limiting current density of 5.06 mA·cm−2. Nitrogen-doped carbon materials are promising for electrochemical energy storage and conversion. Dopant control and pore engineering play important roles in improving their performance. This work demonstrates the synthesis of nitrogen-doped ordered mesoporous carbons (N-OMCs) with bimodal mesopores using the facile solvent-free nanocasting method. The simplest amino acid (glycine, Gly) is adopted as the sole precursor and the ordered mesoporous silica SBA-15 as the hard template. The confined pyrolysis of Gly in SBA-15 leads to efficient carbonization and nitrogen doping and interesting structuration. The N-OMCs possess high surface areas (923–1374 m2·g−1), large pore volumes (1.32–2.21 cm3·g−1), bimodal mesopores (4.8 and 6.2–20 nm) and high nitrogen contents (3.66%–12.23%). The effects of Gly/SBA-15 mass ratio (1–3) and temperature (700–1000 °C) on the physicochemical properties of the N-OMCs are studied. The N-OMCs as electrode materials possess high performance in supercapacitor. The typical sample shows a large specific capacitance of 298 F·g−1, a good rate capability (70 % retention at 30 A·g−1) and a high stability. The different capacitance and rate capability of the N-OMCs are discussed by correlating with their physicochemical properties. The balance of surface area, graphitization, and nitrogen doping and open mesoporous structure is essential to achieve the best performance. The O-NMCs also show good performance in electrocatalytic oxygen reduction reaction (ORR). The typical sample shows high onset and half-wave potentials of 0.92 and 0.83 V and a large limiting current density of 5.06 mA·cm−2.
Preparation of 3D graphene-carbon nanotubes-magnetic hybrid aerogels for dye adsorption
Zu Rong Ang, Ing Kong, Rachel Shin Yie Lee, Cin Kong, Akesh Babu Kakarla, Ai Bao Chai, Wei Kong
, doi: 10.1016/S1872-5805(21)60029-X
摘要(486) HTML(226) PDF(48)
摘要:
Novel hybrid aerogels, which can be magnetically extracted from water to avoid filtration, were prepared by adding ZnCl2, NiCl2·6H2O, FeCl2·4H2O and FeCl3·6H2O into a suspension of graphene oxide and oxidzed carbon nanotubes followed by co-precipatation under basic condition, crosslinking with polyvinyl alcohol in water and freeze-drying. The hybrid aerogels consist of magnetic Ni0.5Zn0.5Fe2O4 nanoparticles, graphene oxide, carbon nanotubes and polyvinyl alcohol, which have active sites that attract dye molecules and can be extracted from water by applying magnetic field. Under an optimal mass ratio of the components, the optimized hybrid aerogel has a high adsorption capacity (qe=71.03 mg g−1 for methylene blue) and a moderate magnetic strength of MS = 3.519 emu g−1. Its removal efficiencies for methylene blue, methyl orange, crystal violet and their mixture with an equal mass are 70.1%, 4.2%, 8.9% and 11.1%, respectively under the same dye concentration of 0.025 mg. mL−1. It can be reused for 3 regeneration cycles with a regeneration efficiency of over 82%. Also it is not toxic to the living organism, suggesting that it is promising as an adsorbent for treating industrial wastewater. Novel hybrid aerogels, which can be magnetically extracted from water to avoid filtration, were prepared by adding ZnCl2, NiCl2·6H2O, FeCl2·4H2O and FeCl3·6H2O into a suspension of graphene oxide and oxidzed carbon nanotubes followed by co-precipatation under basic condition, crosslinking with polyvinyl alcohol in water and freeze-drying. The hybrid aerogels consist of magnetic Ni0.5Zn0.5Fe2O4 nanoparticles, graphene oxide, carbon nanotubes and polyvinyl alcohol, which have active sites that attract dye molecules and can be extracted from water by applying magnetic field. Under an optimal mass ratio of the components, the optimized hybrid aerogel has a high adsorption capacity (qe=71.03 mg g−1 for methylene blue) and a moderate magnetic strength of MS = 3.519 emu g−1. Its removal efficiencies for methylene blue, methyl orange, crystal violet and their mixture with an equal mass are 70.1%, 4.2%, 8.9% and 11.1%, respectively under the same dye concentration of 0.025 mg. mL−1. It can be reused for 3 regeneration cycles with a regeneration efficiency of over 82%. Also it is not toxic to the living organism, suggesting that it is promising as an adsorbent for treating industrial wastewater.
综合评述
碳基非金属纳米材料用于二电子氧还原制备过氧化氢的研究进展
桑志远, 侯峰, 王思惠, 梁骥
, doi: 10.1016/S1872-5805(22)60583-3
摘要(7) HTML(4) PDF(1)
摘要:
电催化二电子氧还原反应(2e-ORR)制备过氧化氢(H2O2)凭借其高效、安全和绿色特点,逐步发展为一种可能替代工业蒽醌法的新途径。碳基纳米材料具有电子导电性高、结构稳定性好、纳米结构调控容易、成本低等优势,是一类具有良好前景的2e-ORR制备H2O2的催化剂。针对该类碳基电催化材料的发展现状及相应材料上的活性中心和反应机制进行详细论述有助于对本领域的最新进展实现全面、系统的认识。本文首先介绍了氧还原反应的四电子、二电子反应路径及相关机制;其次,综述了提高碳基纳米材料二电子氧还原活性和H2O2生成选择性的结构优化策略及其活性中心的设计思路,包括非金属单原子掺杂、双原子掺杂、结构缺陷和表面修饰等。最后,展望了电催化制备H2O2及相关催化材料的发展前景和面临的挑战。 电催化二电子氧还原反应(2e-ORR)制备过氧化氢(H2O2)凭借其高效、安全和绿色特点,逐步发展为一种可能替代工业蒽醌法的新途径。碳基纳米材料具有电子导电性高、结构稳定性好、纳米结构调控容易、成本低等优势,是一类具有良好前景的2e-ORR制备H2O2的催化剂。针对该类碳基电催化材料的发展现状及相应材料上的活性中心和反应机制进行详细论述有助于对本领域的最新进展实现全面、系统的认识。本文首先介绍了氧还原反应的四电子、二电子反应路径及相关机制;其次,综述了提高碳基纳米材料二电子氧还原活性和H2O2生成选择性的结构优化策略及其活性中心的设计思路,包括非金属单原子掺杂、双原子掺杂、结构缺陷和表面修饰等。最后,展望了电催化制备H2O2及相关催化材料的发展前景和面临的挑战。
Design and synthesis of carbon-based nanomaterials with different dimensions for electrochemical energy storage
ZHU Cheng-yu, YE You-wen, GUO Xia, CHENG Fei
, doi: 10.1016/S1872-5805(22)60579-1
摘要(87) HTML(51) PDF(12)
摘要:
With environmental degradation and energy crisis, the storage and utilization of sustainable energy, such as solar, wind energy, etc., become urgent. The attention to electrochemical energy storage (EES) devices, as a means of efficiently storing these emerging energy sources, exhibits an increasing trend. Electrode materials are critical to the performance of EES, and carbon-based nanomaterials have become extremely promising due to their unique and outstanding advantages. The structure design and controllable synthesis of electrode materials thus determine the electrochemical performance of EES to a large extent. Focusing on the unique and outstanding advantages of carbon-based nanomaterials, the preparation progress of carbon-based materials with different dimensions are summarized and discussed, and their applications in different energy storage devices in recent years are also presented. This review facilitates in-depth understanding of the relationship between material structures with different dimensions and electrochemical features, and a perspective and reference to the design and synthesis of exceptional-performance carbon-based nanomaterials for the EES devices are provided. With environmental degradation and energy crisis, the storage and utilization of sustainable energy, such as solar, wind energy, etc., become urgent. The attention to electrochemical energy storage (EES) devices, as a means of efficiently storing these emerging energy sources, exhibits an increasing trend. Electrode materials are critical to the performance of EES, and carbon-based nanomaterials have become extremely promising due to their unique and outstanding advantages. The structure design and controllable synthesis of electrode materials thus determine the electrochemical performance of EES to a large extent. Focusing on the unique and outstanding advantages of carbon-based nanomaterials, the preparation progress of carbon-based materials with different dimensions are summarized and discussed, and their applications in different energy storage devices in recent years are also presented. This review facilitates in-depth understanding of the relationship between material structures with different dimensions and electrochemical features, and a perspective and reference to the design and synthesis of exceptional-performance carbon-based nanomaterials for the EES devices are provided.
碳基集流体材料在钠金属负极中的应用
王艳, 朱铭, 刘昊轩, 张远俊, 吴宽, 王官耀, 吴超
, doi: 10.1016/S1872-5805(22)60581-X
摘要(71) HTML(32) PDF(13)
摘要:
室温钠离子二次电池是锂离子二次电池最有可能的替代品,也被认为是大规模能量存储技术的最有前景的选择之一。金属钠具有超高的理论容量以及低的氧化还原电位,因此被认为是最有前景的高比能钠离子电池的负极材料。然而,钠金属负极的应用仍面临一些挑战性,如钠枝晶的生长、钠金属与电解液之间的副反应、充放电过程中大的体积膨胀等。其中,钠枝晶生长不仅可以产生“死”钠和加速钠金属与电解液之间的副反应,导致容量的快速衰减,而且可能刺穿隔膜,引发电解液燃烧、电池爆炸等严重的安全问题。炭材料家族成员众多,可具有高机械强度、轻质量、高导电性、大比表面积和良好的化学稳定性等特性,近年来被广泛报道用于钠金属负极的集流体的研究。本文综述了最新的碳基集流体材料在钠金属负极上的研究进展,分析了碳基集流体的界面、结构与钠金属负极性能之间的关系,最后并对碳基集流体的未来研究面临的问题进行了展望。 室温钠离子二次电池是锂离子二次电池最有可能的替代品,也被认为是大规模能量存储技术的最有前景的选择之一。金属钠具有超高的理论容量以及低的氧化还原电位,因此被认为是最有前景的高比能钠离子电池的负极材料。然而,钠金属负极的应用仍面临一些挑战性,如钠枝晶的生长、钠金属与电解液之间的副反应、充放电过程中大的体积膨胀等。其中,钠枝晶生长不仅可以产生“死”钠和加速钠金属与电解液之间的副反应,导致容量的快速衰减,而且可能刺穿隔膜,引发电解液燃烧、电池爆炸等严重的安全问题。炭材料家族成员众多,可具有高机械强度、轻质量、高导电性、大比表面积和良好的化学稳定性等特性,近年来被广泛报道用于钠金属负极的集流体的研究。本文综述了最新的碳基集流体材料在钠金属负极上的研究进展,分析了碳基集流体的界面、结构与钠金属负极性能之间的关系,最后并对碳基集流体的未来研究面临的问题进行了展望。
Porous carbons: Favored materials in Electro-Fenton and Fenton-like reactions
PAN Zhe-lun, QIAN Xu-fang
, doi: 10.1016/S1872-5805(22)60578-X
摘要(49) HTML(35) PDF(11)
摘要:
Fenton-like reactions which could overcome the limitations of narrow pH range and excessive sludge production have drawn great attention. Despite the poor catalytic activity toward hydrogen peroxide, the porous carbons could play diverse roles, including catalyst carriers, adsorbents and electrocatalysts for production and activation of hydrogen peroxide, which was an oxidant in Fenton-like reaction. Recent developments in the above fields regarding porous carbons were discussed in this review. Porous carbons possess the advantages of diverse functionality, well-developed synthetic methods, and high chemical and thermal stability, making them favored materials as components of composites in Electro-Fenton and Fenton-like reactions. They effectively promote electron and mass transfer, prevent metal leaching and improve the contaminant degradation efficiency. Fenton-like reactions which could overcome the limitations of narrow pH range and excessive sludge production have drawn great attention. Despite the poor catalytic activity toward hydrogen peroxide, the porous carbons could play diverse roles, including catalyst carriers, adsorbents and electrocatalysts for production and activation of hydrogen peroxide, which was an oxidant in Fenton-like reaction. Recent developments in the above fields regarding porous carbons were discussed in this review. Porous carbons possess the advantages of diverse functionality, well-developed synthetic methods, and high chemical and thermal stability, making them favored materials as components of composites in Electro-Fenton and Fenton-like reactions. They effectively promote electron and mass transfer, prevent metal leaching and improve the contaminant degradation efficiency.
碳基电催化材料选择性合成过氧化氢研究进展
闫啸, 石文武, 王新中
, doi: 10.1016/S1872-5805(22)60582-1
摘要(62) HTML(26) PDF(19)
摘要:
过氧化氢(H2O2)作为一种环境友好型绿色氧化剂,在健康护理、污水处理和化学合成等领域均有广泛应用。近年来,其作为零碳型储氢材料在长期储能领域的应用前景也广受关注。当前H2O2的工业化生产主要依赖蒽醌工艺,步骤复杂、废水废气排放量大,且生产和运输过程存在安全隐患。电催化合成H2O2是近年来兴起的研究热点,通过利用清洁能源为动力源,以水和氧气为原料实现按需现场合成H2O2。兼具高活性、高选择性和稳定性的催化剂是实现高效选择性合成H2O2的关键。本文综述了碳基电催化材料在电催化合成H2O2领域的最新研究进展,包括催化位点调控,反应界面设计和催化剂结构优化等。通过合理设计催化剂组分和活性位点微环境调控,有望制备具有高稳定性的高效催化剂,缩小实验结果与理论预期的差距。希望本文可促进相关研究的进一步发展并最终实现按需合成H2O2的市场化应用。 过氧化氢(H2O2)作为一种环境友好型绿色氧化剂,在健康护理、污水处理和化学合成等领域均有广泛应用。近年来,其作为零碳型储氢材料在长期储能领域的应用前景也广受关注。当前H2O2的工业化生产主要依赖蒽醌工艺,步骤复杂、废水废气排放量大,且生产和运输过程存在安全隐患。电催化合成H2O2是近年来兴起的研究热点,通过利用清洁能源为动力源,以水和氧气为原料实现按需现场合成H2O2。兼具高活性、高选择性和稳定性的催化剂是实现高效选择性合成H2O2的关键。本文综述了碳基电催化材料在电催化合成H2O2领域的最新研究进展,包括催化位点调控,反应界面设计和催化剂结构优化等。通过合理设计催化剂组分和活性位点微环境调控,有望制备具有高稳定性的高效催化剂,缩小实验结果与理论预期的差距。希望本文可促进相关研究的进一步发展并最终实现按需合成H2O2的市场化应用。
炭材料在低温型磷酸铁锂材料中的应用分析及展望
曹贺, 闻雷, 郭震强, 朴楠, 胡广剑, 吴敏杰, 李峰
, doi: 10.1016/S1872-5805(22)60584-5
摘要(20) HTML(9) PDF(10)
摘要:
磷酸铁锂为正极的锂离子电池是目前电动汽车和储能领域应用最为广泛的电池体系之一,具有成本低廉、循环寿命长、安全性好等特点。但磷酸铁锂为正极的锂离子电池在低温下的容量和循环寿命衰减问题一直制约了其在寒冷地区的推广和应用。因此磷酸铁锂材料本身低温放电性能的提高,对于改善磷酸铁锂为正极的锂离子电池体系的低温放电特性具有重要意义。本文首先分析了磷酸铁锂为正极的锂离子电池的低温衰减机制,从炭材料作用的角度评述了低温型磷酸铁锂材料的研究进展,同时也关注了高倍率型磷酸铁锂材料。因磷酸铁锂的高倍率性能与低温特性具有很大的相似之处,两者对材料的要求基本接近,材料的设计原则和方法也基本相同。本文也重点分析了纳米炭材料,如碳纳米管和石墨烯等在低温型磷酸铁锂材料领域的应用。 磷酸铁锂为正极的锂离子电池是目前电动汽车和储能领域应用最为广泛的电池体系之一,具有成本低廉、循环寿命长、安全性好等特点。但磷酸铁锂为正极的锂离子电池在低温下的容量和循环寿命衰减问题一直制约了其在寒冷地区的推广和应用。因此磷酸铁锂材料本身低温放电性能的提高,对于改善磷酸铁锂为正极的锂离子电池体系的低温放电特性具有重要意义。本文首先分析了磷酸铁锂为正极的锂离子电池的低温衰减机制,从炭材料作用的角度评述了低温型磷酸铁锂材料的研究进展,同时也关注了高倍率型磷酸铁锂材料。因磷酸铁锂的高倍率性能与低温特性具有很大的相似之处,两者对材料的要求基本接近,材料的设计原则和方法也基本相同。本文也重点分析了纳米炭材料,如碳纳米管和石墨烯等在低温型磷酸铁锂材料领域的应用。
Research progress on metal and covalent organic frameworks-based materials for high-performance supercapacitors
WANG Shuai, GUO Yu-zhe, WANG Fang-xiao, ZHOU Sheng-hu, ZENG Tian-yu, DONG Yu-bin
, doi: 10.1016/S1872-5805(22)60586-9
摘要(48) HTML(36) PDF(9)
摘要:
Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are serials of crystalline porous materials. MOFs, COFs and their derivatives have attracted much attention in energy storage devices due to their highly ordered structures, large surface areas, tunable pore sizes and topologies as well as well-defined redox-active porous skeletons. Furthermore, MOFs, COFs and their derivatives should have structural stability, an abundance of redox-active sites and improved electronic conductivity to fabricate high-performance supercapacitor electrodes. In this study, we review the recent research progress on the design strategy of MOFs and COFs, the hybridization of MOFs or COFs with conductive materials (e.g. conductive polymer, graphene and carbon nanotubes) and MOF- and COF-derived carbon materials, whose chemical and physical properties, capacitive performances and the structure-property relationships are also discussed. Finally, the challenges and prospects of MOFs- and COFs-based electrode materials are presented. Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are serials of crystalline porous materials. MOFs, COFs and their derivatives have attracted much attention in energy storage devices due to their highly ordered structures, large surface areas, tunable pore sizes and topologies as well as well-defined redox-active porous skeletons. Furthermore, MOFs, COFs and their derivatives should have structural stability, an abundance of redox-active sites and improved electronic conductivity to fabricate high-performance supercapacitor electrodes. In this study, we review the recent research progress on the design strategy of MOFs and COFs, the hybridization of MOFs or COFs with conductive materials (e.g. conductive polymer, graphene and carbon nanotubes) and MOF- and COF-derived carbon materials, whose chemical and physical properties, capacitive performances and the structure-property relationships are also discussed. Finally, the challenges and prospects of MOFs- and COFs-based electrode materials are presented.
In-situ templating synthesis of porous carbons for energy-related applications: A review
GUAN Lu, HU Han, TENG Xiao-ling, ZHU Yi-fan, ZHANG Yun-long, CHAO Hui-xia, YANG Hao, WANG Xiao-shan, WU Ming-bo
, doi: 10.1016/S1872-5805(22)60574-2
摘要(49) HTML(29) PDF(11)
摘要:
Owing to their large specific surface area, high chemical and thermal stability, and good electronic conductivity, porous carbons have found wide applications in the field of electrochemical energy storage and conversion. Their performance hinges heavily on the structure, making the structure regulation of porous carbons the research frontier in the development of these materials. In addition to the straightforward hard-templating processes, the in-situ templating synthesis has been considered as another appealing strategy for the precise engineering of porous carbons. Herein, the recent progress on synthesizing porous carbon materials via in-situ templating processes for energy storage and conversion is summarized. First, the rising of in-situ templating synthesis of porous carbons is outlined by elaborately comparing with the traditional hard templating methods. Then, the in-situ templating methods are classified based on the template formation processes including top-down, state-change, and bottom-up during the syntheses. After that, the performance of these materials in the application of electrochemical energy storage and conversion is presented, highlighting the advantages of the in-situ templating syntheses. At last, the possible obstacles and future perspectives are provided. Owing to their large specific surface area, high chemical and thermal stability, and good electronic conductivity, porous carbons have found wide applications in the field of electrochemical energy storage and conversion. Their performance hinges heavily on the structure, making the structure regulation of porous carbons the research frontier in the development of these materials. In addition to the straightforward hard-templating processes, the in-situ templating synthesis has been considered as another appealing strategy for the precise engineering of porous carbons. Herein, the recent progress on synthesizing porous carbon materials via in-situ templating processes for energy storage and conversion is summarized. First, the rising of in-situ templating synthesis of porous carbons is outlined by elaborately comparing with the traditional hard templating methods. Then, the in-situ templating methods are classified based on the template formation processes including top-down, state-change, and bottom-up during the syntheses. After that, the performance of these materials in the application of electrochemical energy storage and conversion is presented, highlighting the advantages of the in-situ templating syntheses. At last, the possible obstacles and future perspectives are provided.
Advances of carbon materials for stable lithium metal batteries
JIN Cheng-bin, SHI Peng, ZHANG Xue-qiang, HUANG Jia-qi
, doi: 10.1016/S1872-5805(22)60573-0
摘要(161) HTML(62) PDF(44)
摘要:
Lithium (Li) metal is regarded as a promising anode material to construct next-generation high-energy-density batteries. However, the plating/stripping process of Li metal is often accompanied by the formation of high-tortuosity dendrites, which induces the short lifespan and even safety hazards of batteries. To date, various approaches have been developed to suppress the dendrite growth and regulate the uniformity of solid electrolyte interphase. Carbon materials with lightweight, highly conductive, hierarchically porous, chemically and physically stable features have been designed and employed for stabilizing Li metal in distinguishable types. Based on different functions, this review summarizes the advances of carbon materials categorized as hosts, electrolyte additives, and coating layers in stabilizing Li metal batteries (LMBs). The advantages and limitations of various carbon materials have been discussed in terms of structural and chemical aspects. Finally, the outlooks on future developments of carbon materials for propelling the applications of LMBs are proposed. Lithium (Li) metal is regarded as a promising anode material to construct next-generation high-energy-density batteries. However, the plating/stripping process of Li metal is often accompanied by the formation of high-tortuosity dendrites, which induces the short lifespan and even safety hazards of batteries. To date, various approaches have been developed to suppress the dendrite growth and regulate the uniformity of solid electrolyte interphase. Carbon materials with lightweight, highly conductive, hierarchically porous, chemically and physically stable features have been designed and employed for stabilizing Li metal in distinguishable types. Based on different functions, this review summarizes the advances of carbon materials categorized as hosts, electrolyte additives, and coating layers in stabilizing Li metal batteries (LMBs). The advantages and limitations of various carbon materials have been discussed in terms of structural and chemical aspects. Finally, the outlooks on future developments of carbon materials for propelling the applications of LMBs are proposed.
Synthesis of mesoporous carbon materials from renewable plant polyphenol for environmental and energy application
FENG You-you, CHEN Yi-qing, WANG Zheng, WEI Jing
, doi: 10.1016/S1872-5805(22)60577-8
摘要(76) HTML(40) PDF(18)
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Mesoporous carbon materials exhibit high specific surface area, tunable composition and pore structure, good chemical stability and conductivity. They have attracted intensive attentions due to their multifarious applications in environmental remediation, industrial catalysis, energy conversion and storage. The carbon source is an important parameter for synthesis of mesoporous carbon with different properties. Plant polyphenols are one kind of universal biomass for carbon source with low cost, nontoxicity and sustainability. Most importantly, the good adhesive property and metal chelate ability for plant polyphenol can be used to synthesize mesoporous carbon composites. Despite great progress, there are few reviews on the topic of mesoporous carbon derived from plant polyphenol. In this review, different kinds of mesoporous carbon materials originated from plant polyphenols have been systematically summed up, including porous carbon foam, ordered mesoporous carbon, mesoporous carbon spheres, heteroatom doped carbon, and mesoporous metal/carbon composites. Then, the applications of these mesoporous carbon in environmental and energy are summarized. This review will bring the bridge for the research of polyphenol chemistry and nanoporous carbon. It would inspire more researchers to explore the functional mesoporous carbon employing plant polyphenol as a sustainable carbon source. Mesoporous carbon materials exhibit high specific surface area, tunable composition and pore structure, good chemical stability and conductivity. They have attracted intensive attentions due to their multifarious applications in environmental remediation, industrial catalysis, energy conversion and storage. The carbon source is an important parameter for synthesis of mesoporous carbon with different properties. Plant polyphenols are one kind of universal biomass for carbon source with low cost, nontoxicity and sustainability. Most importantly, the good adhesive property and metal chelate ability for plant polyphenol can be used to synthesize mesoporous carbon composites. Despite great progress, there are few reviews on the topic of mesoporous carbon derived from plant polyphenol. In this review, different kinds of mesoporous carbon materials originated from plant polyphenols have been systematically summed up, including porous carbon foam, ordered mesoporous carbon, mesoporous carbon spheres, heteroatom doped carbon, and mesoporous metal/carbon composites. Then, the applications of these mesoporous carbon in environmental and energy are summarized. This review will bring the bridge for the research of polyphenol chemistry and nanoporous carbon. It would inspire more researchers to explore the functional mesoporous carbon employing plant polyphenol as a sustainable carbon source.
介孔炭材料应用于电化学催化的研究进展
梁振金, 洪梓博, 解明月, 顾栋
, doi: 10.1016/S1872-5805(22)60575-4
摘要(87) HTML(59) PDF(31)
摘要:
由于介孔炭材料具有高比表面、均一可调的孔径尺寸和形貌、良好的导电性和化学稳定性等优点,已被广泛应用到催化、吸附、分离和电化学储能等领域。近年来,多组分的掺杂与复合使介孔炭材料拥有可调变的功能性,已成为材料领域研究的一个热点。本文首先介绍介孔炭材料的合成,包括软模板法、硬模板法和无模板法等。接着论述介孔炭及其复合材料在电化学催化领域的应用,主要包括杂原子掺杂介孔炭材料以及介孔炭材料与金属化合物的复合材料在电化学催化氧还原(ORR)、析氧(OER)、析氢(HER)等领域的研究进展。此外还论述了此类材料在电催化有机合成上的应用。最后对介孔炭及其复合材料在电化学催化上的发展趋势进行了展望。 由于介孔炭材料具有高比表面、均一可调的孔径尺寸和形貌、良好的导电性和化学稳定性等优点,已被广泛应用到催化、吸附、分离和电化学储能等领域。近年来,多组分的掺杂与复合使介孔炭材料拥有可调变的功能性,已成为材料领域研究的一个热点。本文首先介绍介孔炭材料的合成,包括软模板法、硬模板法和无模板法等。接着论述介孔炭及其复合材料在电化学催化领域的应用,主要包括杂原子掺杂介孔炭材料以及介孔炭材料与金属化合物的复合材料在电化学催化氧还原(ORR)、析氧(OER)、析氢(HER)等领域的研究进展。此外还论述了此类材料在电催化有机合成上的应用。最后对介孔炭及其复合材料在电化学催化上的发展趋势进行了展望。
Nitrogen-enriched Crumpled Graphene for High-Mass-Loading Supercapacitor with Extraordinary Volumetric Capacitance
YU Qiong, WANG Yong-zhi, MENG Meng, SHEN Shu-ling, TANG Zhi-hong, YANG Jun-he
, doi: 10.1016/S1872-5805(22)60599-7
摘要(3) HTML(7) PDF(0)
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The low volumetric capacity and sluggish diffusion at high mass loading hindered the application of supercapacitor in portable electronics and electric automobiles. In this work, crumpled graphene with nitrogen content of 11.38 atm% was obtained by the heat shock of crumpled graphene/urea composite. The volumetric capacitance as high as 384.0 F cm−3 and fast ions transfer were achieved by using the crumpled graphene as electrodes. Even at high current density (10 A g−1) and high loading (21.00 mg per electrode), the specific capacitance retention could still be 76.3% and 83.6%, respectively. It was proposed that N2 (pyrrole, imide, lactam, or other types of pyridine-like nitrogen) and high surface area of the sample were key factors for improving the capacitance, and crumpled structure provided high mass transfer of the ions. Furthermore, as many as thirty-six white light-emitting diodes (assemble as “USST”) were powered by four nitrogen-enriched crumpled graphene-based supercapacitor coins, and the emitting-time of “USST” can sustain as long as 10 minutes with one-charge. The low volumetric capacity and sluggish diffusion at high mass loading hindered the application of supercapacitor in portable electronics and electric automobiles. In this work, crumpled graphene with nitrogen content of 11.38 atm% was obtained by the heat shock of crumpled graphene/urea composite. The volumetric capacitance as high as 384.0 F cm−3 and fast ions transfer were achieved by using the crumpled graphene as electrodes. Even at high current density (10 A g−1) and high loading (21.00 mg per electrode), the specific capacitance retention could still be 76.3% and 83.6%, respectively. It was proposed that N2 (pyrrole, imide, lactam, or other types of pyridine-like nitrogen) and high surface area of the sample were key factors for improving the capacitance, and crumpled structure provided high mass transfer of the ions. Furthermore, as many as thirty-six white light-emitting diodes (assemble as “USST”) were powered by four nitrogen-enriched crumpled graphene-based supercapacitor coins, and the emitting-time of “USST” can sustain as long as 10 minutes with one-charge.
Hybridization of activated carbon cloths with electrospun nanofibers for particle filtration
YANG Yun-long, LI Ming-zhe, HOU Shi-yu, LV Rui-tao, KANG Fei-yu, HUANG Zheng-Hong
, doi: 10.1016/S1872-5805(22)60598-5
摘要(10) HTML(13) PDF(1)
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Activated carbon fiber (ACF) possess high adsorption capacities and can be used in the treatment of benzene, while electrospun nanofibers are expected to be used as used as filtration material due to their intercepting capability to particles. In this work, two series hybrids of electrospun nanofibers and activated carbon cloths were prepared through electrospinning the polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) nanofibers onto the phenolic resin based activated carbon fiber (PRACFC). The filtration performance of hybrids was evaluated by a filtration efficiency system. The results indicate a positive correlation between the filtration efficiency and the amounts of electrospun nanofiber. Surprisingly, the filtration efficiencies increase with the increasing of air velocity, which is attributed to the piezoelectric effect introduced by electrospun nanofibers. Moreover, the hybrids have a good adsorption capacity towards benzene as well. It suggests that the hybrid of electrospun nanofibers and activated carbon cloth are promising to be used in air pollution treatment. Activated carbon fiber (ACF) possess high adsorption capacities and can be used in the treatment of benzene, while electrospun nanofibers are expected to be used as used as filtration material due to their intercepting capability to particles. In this work, two series hybrids of electrospun nanofibers and activated carbon cloths were prepared through electrospinning the polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) nanofibers onto the phenolic resin based activated carbon fiber (PRACFC). The filtration performance of hybrids was evaluated by a filtration efficiency system. The results indicate a positive correlation between the filtration efficiency and the amounts of electrospun nanofiber. Surprisingly, the filtration efficiencies increase with the increasing of air velocity, which is attributed to the piezoelectric effect introduced by electrospun nanofibers. Moreover, the hybrids have a good adsorption capacity towards benzene as well. It suggests that the hybrid of electrospun nanofibers and activated carbon cloth are promising to be used in air pollution treatment.
Oxidation reaction mechanism and kinetics of ethylene tar for preparation of carbonaceous precursor
GUO Tian-rui, CHEN Rong-qi, GAO Wei, WANG Yan-li, ZHAN Liang
, doi: 10.1016/S1872-5805(22)60597-3
摘要(4) HTML(13) PDF(0)
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To obtain excellent carbonaceous precursors, the oxidation reaction mechanism and kinetics of ethylene tar were investigated. The oxidation process of ethylene tar was divided into three stages (350-550 K, 550-700 K and 700-900 K) according to the thermogravimetric curve. To reveal the oxidation reaction mechanism of ethylene tar, the components of evolved gases at different stages were further analyzed online by mass spectrometry and infrared technology. Then, based on the thermogravimetric curve of ethylene tar at different reaction temperatures, the whole reaction process was divided into four parts to perform kinetics simulation calculation. With the help of the iso-conversional method (Coats-Redfern) to analyze the linear regression rates (R2) between 17 common reaction kinetics models and experimental data, the optimal reaction kinetics model for expressing oxidation process of ethylene tar was determined. The results show that: (1) In the oxidation process, the side chains of aromatic compounds firstly react with oxygen to form alcohols and aldehydes, leaving peroxy-radicals to aromatic rings. After that, the aromatic compounds with peroxy-radicals undergo polymerization/condensation reaction to form larger molecular. (2) The fourth-order of reaction model is adopted to describe the first three parts of the oxidation process, and the activation energies are 47.330 kJ·mol−1, 18.689 kJ·mol−1 and 9.004 kJ·mol−1 respectively. The three-dimensional diffusion model is applied to the fourth part of the oxidation process, and the activation energy is 88.369 kJ·mol−1. To obtain excellent carbonaceous precursors, the oxidation reaction mechanism and kinetics of ethylene tar were investigated. The oxidation process of ethylene tar was divided into three stages (350-550 K, 550-700 K and 700-900 K) according to the thermogravimetric curve. To reveal the oxidation reaction mechanism of ethylene tar, the components of evolved gases at different stages were further analyzed online by mass spectrometry and infrared technology. Then, based on the thermogravimetric curve of ethylene tar at different reaction temperatures, the whole reaction process was divided into four parts to perform kinetics simulation calculation. With the help of the iso-conversional method (Coats-Redfern) to analyze the linear regression rates (R2) between 17 common reaction kinetics models and experimental data, the optimal reaction kinetics model for expressing oxidation process of ethylene tar was determined. The results show that: (1) In the oxidation process, the side chains of aromatic compounds firstly react with oxygen to form alcohols and aldehydes, leaving peroxy-radicals to aromatic rings. After that, the aromatic compounds with peroxy-radicals undergo polymerization/condensation reaction to form larger molecular. (2) The fourth-order of reaction model is adopted to describe the first three parts of the oxidation process, and the activation energies are 47.330 kJ·mol−1, 18.689 kJ·mol−1 and 9.004 kJ·mol−1 respectively. The three-dimensional diffusion model is applied to the fourth part of the oxidation process, and the activation energy is 88.369 kJ·mol−1.
Se encapsulated into honeycomb 3D porous carbon with Se-C bonds as superb performance cathodes for Li-Se Batteries
XIA Zhi-gang, ZHANG Jing-jing, FAN Mei-qiang, LV Chun-ju, CHEN Zhi, LI Chao
, doi: 10.1016/S1872-5805(22)60596-1
摘要(5) HTML(4) PDF(0)
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Li-Se Batteries has been considered as promising lithium-ion batteries due to their super volumetric energy density and high electrical conductivity of Se. However, the development of Li-Se batteries application is impeded by the boring volume expansion and polyselenide dissolution of electrodes during cycling, as well as the low selenium loading. A feasible and effective approach to settle these three issues is to keep selenium into a carbon host with sufficient pore volume and simultaneously enhance the interfacial interaction between selenium and carbon. A novel cathode material of Se encapsulated into honeycomb 3D porous carbon (HPC@Se) with Se-C bonds for Li-Se Batteries is synthesized by impregnating Se into the tartrate salt derived honeycomb 3D porous carbon. The pore volume of the obtained honeycomb 3D porous carbon is up to 1.794 cm3 g−1, which allows 65%wt selenium to be uniformly encapsulated. Moreover, the strong chemical bonds between selenium and carbon are beneficial for stabilizing selenium, thus further relieving its huge volume expansion and polyselenide dissolution as well as promote the charge transfer during cycling. As expected, HPC@Se cathode presents fantastic cyclability and rate performance. After 200 cycles, its specific capacity remained at 561 mA h g−1 (83% of the theoretical specific capacity) at 0.2 C. And the capacity recession is just 0.058 percentage each cycle. Besides, HPC@Se cathode can also demonstrate a considerable capacity of 472.8 mA h g−1 under the higher current density of 5 C. Li-Se Batteries has been considered as promising lithium-ion batteries due to their super volumetric energy density and high electrical conductivity of Se. However, the development of Li-Se batteries application is impeded by the boring volume expansion and polyselenide dissolution of electrodes during cycling, as well as the low selenium loading. A feasible and effective approach to settle these three issues is to keep selenium into a carbon host with sufficient pore volume and simultaneously enhance the interfacial interaction between selenium and carbon. A novel cathode material of Se encapsulated into honeycomb 3D porous carbon (HPC@Se) with Se-C bonds for Li-Se Batteries is synthesized by impregnating Se into the tartrate salt derived honeycomb 3D porous carbon. The pore volume of the obtained honeycomb 3D porous carbon is up to 1.794 cm3 g−1, which allows 65%wt selenium to be uniformly encapsulated. Moreover, the strong chemical bonds between selenium and carbon are beneficial for stabilizing selenium, thus further relieving its huge volume expansion and polyselenide dissolution as well as promote the charge transfer during cycling. As expected, HPC@Se cathode presents fantastic cyclability and rate performance. After 200 cycles, its specific capacity remained at 561 mA h g−1 (83% of the theoretical specific capacity) at 0.2 C. And the capacity recession is just 0.058 percentage each cycle. Besides, HPC@Se cathode can also demonstrate a considerable capacity of 472.8 mA h g−1 under the higher current density of 5 C.
N/S co-doped interconnected porous carbon nanosheets as high-performance supercapacitor electrode materials
WEI Yu-chen, ZHOU Jian, YANG Lei, GU Jing, CHEN Zhi-peng, HE Xiao-jun
, doi: 10.1016/S1872-5805(22)60595-X
摘要(11) HTML(7) PDF(1)
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It is a big challenge to synthesize porous carbon nanosheets without acid treatment for high-performance supercapacitors (SCs). Herein, we report a facile and no pickling method to construct N/S co-doped interconnected porous carbon nanosheets (NS-IPCNs) from coal tar pitch (CTP). The as-prepared NS-IPCN800 has interconnected three-dimensional (3D) structure composed of two-dimensional (2D) nanosheets with abundant hierarchical pores. Of which, rich microspores increase active sites for electrolyte ion adsorption and short mesopores provide channels for ion transmission. In addition, interconnected 3D structure provides highways for electrons transportation. Heteroatom doping provides additional pseudocapacitance for NS-IPCNs electrodes. Benefitting from these merits, NS-IPCN800 electrode exhibits an excellent capacitance of 302 F g−1 at 0.05 A g−1 in 6 mol L−1 KOH electrolyte. Besides, the NS-IPCN800 capacitor shows high energy density of 9.71 Wh kg−1 at power density of 25.98 W kg−1. More importantly, NS-IPCN800 capacitor exhibits superior cycle stability with capacitance retention over 94.2% after 10,000 charge-discharge cycles. This work opens a less harmful strategy for constructing NS-IPCNs from CTP as high-performance SC electrode materials. It is a big challenge to synthesize porous carbon nanosheets without acid treatment for high-performance supercapacitors (SCs). Herein, we report a facile and no pickling method to construct N/S co-doped interconnected porous carbon nanosheets (NS-IPCNs) from coal tar pitch (CTP). The as-prepared NS-IPCN800 has interconnected three-dimensional (3D) structure composed of two-dimensional (2D) nanosheets with abundant hierarchical pores. Of which, rich microspores increase active sites for electrolyte ion adsorption and short mesopores provide channels for ion transmission. In addition, interconnected 3D structure provides highways for electrons transportation. Heteroatom doping provides additional pseudocapacitance for NS-IPCNs electrodes. Benefitting from these merits, NS-IPCN800 electrode exhibits an excellent capacitance of 302 F g−1 at 0.05 A g−1 in 6 mol L−1 KOH electrolyte. Besides, the NS-IPCN800 capacitor shows high energy density of 9.71 Wh kg−1 at power density of 25.98 W kg−1. More importantly, NS-IPCN800 capacitor exhibits superior cycle stability with capacitance retention over 94.2% after 10,000 charge-discharge cycles. This work opens a less harmful strategy for constructing NS-IPCNs from CTP as high-performance SC electrode materials.
褶皱氧化石墨烯的制备与应用研究进展
曾旭, 朱彬彬, 邱伟, 李伟丽, 郑晓慧, 徐斌
, doi: 10.1016/S1872-5805(22)60594-8
摘要(24) HTML(12) PDF(7)
摘要:
氧化石墨烯(GO)作为二维纳米材料石墨烯的衍生物,具有制备简单、成本低、官能团丰富、易于改性等特点。在GO二维纳米片层上引入褶皱,可改变其形貌和结构,带来特殊的物理、化学、生物等特性,在一些领域具有独特的应用优势。本文综述了国内外近年来在褶皱氧化石墨烯(WGO)的制备与应用方面的研究进展,重点讨论了预拉伸法、溶剂诱导法、快速干燥法和pH值调控法等方法制备WGO的原理和特点,同时总结了WGO在智能器件、生物医药和水处理方面的应用。论文还分析了当前在WGO制备和应用方面存在的问题,并展望了其未来发展趋势。 氧化石墨烯(GO)作为二维纳米材料石墨烯的衍生物,具有制备简单、成本低、官能团丰富、易于改性等特点。在GO二维纳米片层上引入褶皱,可改变其形貌和结构,带来特殊的物理、化学、生物等特性,在一些领域具有独特的应用优势。本文综述了国内外近年来在褶皱氧化石墨烯(WGO)的制备与应用方面的研究进展,重点讨论了预拉伸法、溶剂诱导法、快速干燥法和pH值调控法等方法制备WGO的原理和特点,同时总结了WGO在智能器件、生物医药和水处理方面的应用。论文还分析了当前在WGO制备和应用方面存在的问题,并展望了其未来发展趋势。
Peat-Derived Nitrogen-Doped Porous Carbon as Photothermal-assisted Visible-light Photocatalyst for Water Splitting
BAI Jin-peng, XIAO Nan, SONG Xue-dan, XIAO Jian, and QIU Jie-shan
, doi: 10.1016/S1872-5805(22)60593-6
摘要(31) HTML(16) PDF(4)
摘要:
Photocatalytic H2 evolution reaction is considered as one of the most promising technologies for H2 production. Carbon materials are potential candidates for large-scale and cost-effective photocatalytic water splitting, yet their activity needs to be further enhanced. Here, we report the synthesis of nitrogen-doped porous carbon with peat moss as precursor and urea as nitrogen source and the properties of the as-synthesized carbons as photothermal-assisted visible-light photocatalyst. Due to the photothermal effect, the system temperature rises quickly, up to 55 oC within 15 min under visible light irradiation, which subsequently helps to increase the photocatalytic activity by about 25%. It has been found that the crystallinity and doping content of nitrogen of the peat-derived carbon materials can be tuned by changing the carbonization temperature, which have an impact on the photocatalytic activity of the concerned carbons. Under the photothermal-assisted visible-light conditions, the peat-derived carbon with N content of 4.88 at.% and an appropriate crystallinity exhibits an outstanding photocatalytic activity, evidenced by the high H2 evolution rate of 75.6 μ mol H2 g−1 h−1. Photocatalytic H2 evolution reaction is considered as one of the most promising technologies for H2 production. Carbon materials are potential candidates for large-scale and cost-effective photocatalytic water splitting, yet their activity needs to be further enhanced. Here, we report the synthesis of nitrogen-doped porous carbon with peat moss as precursor and urea as nitrogen source and the properties of the as-synthesized carbons as photothermal-assisted visible-light photocatalyst. Due to the photothermal effect, the system temperature rises quickly, up to 55 oC within 15 min under visible light irradiation, which subsequently helps to increase the photocatalytic activity by about 25%. It has been found that the crystallinity and doping content of nitrogen of the peat-derived carbon materials can be tuned by changing the carbonization temperature, which have an impact on the photocatalytic activity of the concerned carbons. Under the photothermal-assisted visible-light conditions, the peat-derived carbon with N content of 4.88 at.% and an appropriate crystallinity exhibits an outstanding photocatalytic activity, evidenced by the high H2 evolution rate of 75.6 μ mol H2 g−1 h−1.
MXene材料用于柔性传感器的研究进展
姜晶, 陈星, 牛夷, 何欣芮, 胡娅林, 王超
, doi: 10.1016/S1872-5805(22)60589-4
摘要(104) HTML(86) PDF(30)
摘要:
随着柔性电子学的快速发展,有望实现具有高灵敏度和宽检测范围的柔性传感器。近年来,二维层状过渡金属碳氮材料MXene由于具有高导电性、高比表面积、优异的亲水性及良好的机械性能等特点,且能够与包括碳材料(碳纳米管、碳纤维、石墨烯等)在内的多种材料形成性能优异的复合材料,在柔性传感器领域受到众多研究者们的关注。在本篇综述中,首先介绍MXene材料的结构、合成等内容,随后总结MXene柔性传感器的结构、性能指标和常用制备工艺。在此基础上,回顾了多种MXene柔性传感器,详细介绍它们的传感机制和制备技术。最后,总结MXene材料用于柔性传感器的研究趋势。 随着柔性电子学的快速发展,有望实现具有高灵敏度和宽检测范围的柔性传感器。近年来,二维层状过渡金属碳氮材料MXene由于具有高导电性、高比表面积、优异的亲水性及良好的机械性能等特点,且能够与包括碳材料(碳纳米管、碳纤维、石墨烯等)在内的多种材料形成性能优异的复合材料,在柔性传感器领域受到众多研究者们的关注。在本篇综述中,首先介绍MXene材料的结构、合成等内容,随后总结MXene柔性传感器的结构、性能指标和常用制备工艺。在此基础上,回顾了多种MXene柔性传感器,详细介绍它们的传感机制和制备技术。最后,总结MXene材料用于柔性传感器的研究趋势。
Recent advances in electroreduction of carbon dioxide to formic acid over carbon-based materials
LI Wen-bin, YU Chang, TAN Xin-yi, CUI Song, ZHANG Ya-fang, QIU Jie-shan
, doi: 10.1016/S1872-5805(22)60592-4
摘要(65) HTML(22) PDF(13)
摘要:
Electroreduction of carbon dioxide (CO2) driven by renewable and intermittent energy is an important route of CO2 conversion and utilization. Formic acid (HCOOH), as an important chemical basic raw material and safe hydrogen storage material, is one of the main and promising products for CO2 electroreduction. In this review, the physical and chemical properties of CO2 and the reaction mechanism for CO2 electroreduction to HCOOH were outlined in detail. Subsequently, recent development of carbon-based catalysts including metal-free carbon catalysts, carbon-supported catalysts for CO2 electroreduction to HCOOH was also reviewed. Moreover, the design and optimization strategy of reactors for HCOOH production was summarized and commented. Specially, the hybrid CO2 electrolysis technology was analyzed by taking CO2 electroreduction coupled with methanol electrooxidation reaction as an example. Lastly, the key challenges and development directions for CO2 electroreduction to HCOOH were presented, which is expected to provide a novel idea and guidance for further progresses of this technique. Electroreduction of carbon dioxide (CO2) driven by renewable and intermittent energy is an important route of CO2 conversion and utilization. Formic acid (HCOOH), as an important chemical basic raw material and safe hydrogen storage material, is one of the main and promising products for CO2 electroreduction. In this review, the physical and chemical properties of CO2 and the reaction mechanism for CO2 electroreduction to HCOOH were outlined in detail. Subsequently, recent development of carbon-based catalysts including metal-free carbon catalysts, carbon-supported catalysts for CO2 electroreduction to HCOOH was also reviewed. Moreover, the design and optimization strategy of reactors for HCOOH production was summarized and commented. Specially, the hybrid CO2 electrolysis technology was analyzed by taking CO2 electroreduction coupled with methanol electrooxidation reaction as an example. Lastly, the key challenges and development directions for CO2 electroreduction to HCOOH were presented, which is expected to provide a novel idea and guidance for further progresses of this technique.
The Influence of Heteroatom doping on Carbon-based Electrocatalysts for Oxygen Evolution Reaction
WANG Yong-zhi, TANG Zhi-hong, SHEN Shu-ling, YANG Jun-he
, doi: 10.1016/S1872-5805(22)60591-2
摘要(60) HTML(25) PDF(3)
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In recent years, various types of renewable energy conversion and storage equipment have been researched due to the energy over consumption and environmental pollution. Designing effective electrocatalysts is the key to improve the energy conversion efficiency. Understanding and analyzing the mechanism of action of electrocatalysts, especially metal-free doped carbon-based electrocatalysts, is essential for their applications. However, few reviews have summarized and analyzed in more detail the improvement of OER activity due to heteroatom doping. In this overview, the metal-free heteroatom doped carbon-based electrocatalysts including N, P, S and B are summarized, and the mechanisms for improving the electrocatalysis of them are analyzed. Furthermore, the co-doped carbon materials, such as N/P, N/S, as electrocatalysts and the mechanism are also summarized briefly. Finally, the problems that need to be solved and challenge in the future are proposed, the suitable doping methods for metal-free heteroatoms and the corresponding reasons are also given. In recent years, various types of renewable energy conversion and storage equipment have been researched due to the energy over consumption and environmental pollution. Designing effective electrocatalysts is the key to improve the energy conversion efficiency. Understanding and analyzing the mechanism of action of electrocatalysts, especially metal-free doped carbon-based electrocatalysts, is essential for their applications. However, few reviews have summarized and analyzed in more detail the improvement of OER activity due to heteroatom doping. In this overview, the metal-free heteroatom doped carbon-based electrocatalysts including N, P, S and B are summarized, and the mechanisms for improving the electrocatalysis of them are analyzed. Furthermore, the co-doped carbon materials, such as N/P, N/S, as electrocatalysts and the mechanism are also summarized briefly. Finally, the problems that need to be solved and challenge in the future are proposed, the suitable doping methods for metal-free heteroatoms and the corresponding reasons are also given.
聚阴离子化合物在固态电解质中的应用研究进展
张思雨, 李跃然, 邢涛, 刘海燕, 刘昭斌, 李忠涛, 吴明铂
, doi: 10.1016/S1872-5805(22)60588-2
摘要(422) HTML(43) PDF(16)
摘要:
固态电解质是全固态锂电池的关键组分,其室温离子电导率和可加工性是影响电解质性能的关键指标。聚阴离子型固态电解质具有较高的锂离子迁移率,与其它类型陶瓷电解质相比,该电解质特有的对水氧不敏感、成本低廉且原料无毒等优点,大大降低了后期产业化的难度。本文首先总结了聚阴离子型固态电解质的分类和离子传输机制,随后介绍了提高材料本体锂离子传输性的原理和方法,最后介绍了通过表面修饰和复合改性提高电解质界面稳定性和可加工性方面的进展。并结合全固态电池产业化对电解质膜片的需求,探索了目前聚阴离子型固态电池存在的问题和未来发展方向。作为一种具有优异的水氧稳定性和高离子电导率的电解质材料,聚阴离子电解质在下一代全固态电池中有着巨大的应用潜力。 固态电解质是全固态锂电池的关键组分,其室温离子电导率和可加工性是影响电解质性能的关键指标。聚阴离子型固态电解质具有较高的锂离子迁移率,与其它类型陶瓷电解质相比,该电解质特有的对水氧不敏感、成本低廉且原料无毒等优点,大大降低了后期产业化的难度。本文首先总结了聚阴离子型固态电解质的分类和离子传输机制,随后介绍了提高材料本体锂离子传输性的原理和方法,最后介绍了通过表面修饰和复合改性提高电解质界面稳定性和可加工性方面的进展。并结合全固态电池产业化对电解质膜片的需求,探索了目前聚阴离子型固态电池存在的问题和未来发展方向。作为一种具有优异的水氧稳定性和高离子电导率的电解质材料,聚阴离子电解质在下一代全固态电池中有着巨大的应用潜力。
Carbon-Based Metal-Free ORR Electrocatalysts: Past, Present and Future
AN Fu, BAO Xiao-qing, DENG Xiao-yang, MA Zi-zai, WANG Xiao-guang
, doi: 10.1016/S1872-5805(22)60590-0
摘要(52) HTML(29) PDF(10)
摘要:
In recent years, metal-free carbon materials have shown great research value and application potential in replacing high-cost Pt-based oxygen reduction electrocatalysts. A myriads of research papers in this field have been dedicated to the preparation and characterization of various metal-free nanocarbon materials, as well as to their practical applications. Non-metal heteroatom doping and introduction of edge defects are typical nanocarbon modification methods, which can significantly reduce the overpotential of ORR in alkaline and acidic electrolytes. In order to perform well in activity in actual devices such as fuel cells, it is necessary to enhance the ORR intrinsic activity of nanocarbon. Despite lots of publications in this field, the intrinsic relationship between nanocarbon composition, structure regulation and carbon catalytic activity remains not very clear up to date, thus still needing to be explored. The basic goal of this review is to present the various nanocarbons as well as their reaction mechanisms for the ORR so as to propose scientific and specific structural modification strategies. Therefore, this article will summarize and prospect the development of carbon-based metal-free electrocatalysts in the field of oxygen reduction catalysis in recent years, aiming to provide relevant knowledge for the design, synthesis and application of carbon-based non-metallic oxygen reduction catalysts in the future. In recent years, metal-free carbon materials have shown great research value and application potential in replacing high-cost Pt-based oxygen reduction electrocatalysts. A myriads of research papers in this field have been dedicated to the preparation and characterization of various metal-free nanocarbon materials, as well as to their practical applications. Non-metal heteroatom doping and introduction of edge defects are typical nanocarbon modification methods, which can significantly reduce the overpotential of ORR in alkaline and acidic electrolytes. In order to perform well in activity in actual devices such as fuel cells, it is necessary to enhance the ORR intrinsic activity of nanocarbon. Despite lots of publications in this field, the intrinsic relationship between nanocarbon composition, structure regulation and carbon catalytic activity remains not very clear up to date, thus still needing to be explored. The basic goal of this review is to present the various nanocarbons as well as their reaction mechanisms for the ORR so as to propose scientific and specific structural modification strategies. Therefore, this article will summarize and prospect the development of carbon-based metal-free electrocatalysts in the field of oxygen reduction catalysis in recent years, aiming to provide relevant knowledge for the design, synthesis and application of carbon-based non-metallic oxygen reduction catalysts in the future.
Sensitive electrochemical detection of phenacetin on electrochemically reduced graphene oxide modified glassy carbon electrode
MENG Xiao-tong, ZHU De-jing, JIANG Yu-hang, CAO Yue, SI Wei-meng, CAO Jun, LI Qiu-hong Li, LI Jiao, LEI Wu
, doi: 10.1016/S1872-5805(21)60087-2
摘要(30) HTML(37) PDF(2)
摘要:
It is known that the electrochemical determination of phenacetin, a widely used analgesic, is challenging for the interference of these electroactive intermediates acetaminophen (APAP). Phenacetin has been proved being electroactive in 1980s, but the electrochemical determination have not been widely reported. We studied the electrochemical behavior on electrochemical reduced graphene (ERGO) modified electrode, and the comparative experiment was performed on ERGO several nitrogen-doped graphene. ERGO was proved possessing higher current response and lower oxidation potential, A detection limit of 0.91 μM was established. It suggested ERGO modified electrode is a desirable phenacetin sensor. The redox mechanism of phenacetin was interfered via electrochemical experiments, and the reaction under different pH value was proposed. Acetaminophen was considered the main intermediate. The interfering between acetaminophen and phenacetin was studied, the main electroactive intermediate acetaminophen was proved not interfered the determination of phenacetin. But phenacetin was considered interfered with the response of APAP obviously, suggesting that simultaneous detection of phenacetin and APAP via DPV is not reliable. Interference experiment results further illustrated that usual species, such as Cu2+, Al3+, methanol, ethylene glycol, glucose, and ascorbic acid, hardly caused interference. It is known that the electrochemical determination of phenacetin, a widely used analgesic, is challenging for the interference of these electroactive intermediates acetaminophen (APAP). Phenacetin has been proved being electroactive in 1980s, but the electrochemical determination have not been widely reported. We studied the electrochemical behavior on electrochemical reduced graphene (ERGO) modified electrode, and the comparative experiment was performed on ERGO several nitrogen-doped graphene. ERGO was proved possessing higher current response and lower oxidation potential, A detection limit of 0.91 μM was established. It suggested ERGO modified electrode is a desirable phenacetin sensor. The redox mechanism of phenacetin was interfered via electrochemical experiments, and the reaction under different pH value was proposed. Acetaminophen was considered the main intermediate. The interfering between acetaminophen and phenacetin was studied, the main electroactive intermediate acetaminophen was proved not interfered the determination of phenacetin. But phenacetin was considered interfered with the response of APAP obviously, suggesting that simultaneous detection of phenacetin and APAP via DPV is not reliable. Interference experiment results further illustrated that usual species, such as Cu2+, Al3+, methanol, ethylene glycol, glucose, and ascorbic acid, hardly caused interference.
Rational design of 3D CNTs/Ti3C2Tx aerogel modified separator as a LiPS regulator for Li–S batteries
YIN Fei, JIN Qi, ZHANG Xi-tian, WU Li-li
, doi: 10.1016/S1872-5805(21)60085-9
摘要(113) HTML(67) PDF(16)
摘要:
Lithium–sulfur (Li–S) batteries suffer from fast capacity fading and inferior rate performance due to severe polysulfide (LiPS) shuttle and slow redox kinetics. To solve these issues, three-dimensional (3D) CNTs/Ti3C2Tx aerogel was successfully prepared with Ti3C2Tx as the active matrix and CNTs as the conductive pillars, and utilized as a LiPS immobilizer and promoter to modify the commercial Li–S battery separator. The unique design of highly porous 3D aerogel structure results in the sufficient exposure of Ti3C2Tx active sites by preventing their restacking, which not only offers abundant charge transport pathways, but also strengthens the adsorption and catalytic conversion of LiPSs. Moreover, the introduction of CNTs forms a highly conductive network to connect the adjacent Ti3C2Tx sheets, thereby improving the conductivity and structure robustness of the 3D aerogel. Owing to these merits, Li–S cells using CNTs/Ti3C2Tx aerogel modified separator show a high rate capacity of 1043.2 mAh g–1 up to 2 C and an admirable cycling life over 800 cycles at 0.5 C with a low capacity decay rate of 0.07% per cycle. Lithium–sulfur (Li–S) batteries suffer from fast capacity fading and inferior rate performance due to severe polysulfide (LiPS) shuttle and slow redox kinetics. To solve these issues, three-dimensional (3D) CNTs/Ti3C2Tx aerogel was successfully prepared with Ti3C2Tx as the active matrix and CNTs as the conductive pillars, and utilized as a LiPS immobilizer and promoter to modify the commercial Li–S battery separator. The unique design of highly porous 3D aerogel structure results in the sufficient exposure of Ti3C2Tx active sites by preventing their restacking, which not only offers abundant charge transport pathways, but also strengthens the adsorption and catalytic conversion of LiPSs. Moreover, the introduction of CNTs forms a highly conductive network to connect the adjacent Ti3C2Tx sheets, thereby improving the conductivity and structure robustness of the 3D aerogel. Owing to these merits, Li–S cells using CNTs/Ti3C2Tx aerogel modified separator show a high rate capacity of 1043.2 mAh g–1 up to 2 C and an admirable cycling life over 800 cycles at 0.5 C with a low capacity decay rate of 0.07% per cycle.
Structure and Electrochemical properties of coconut shell-based hard carbon as anode materials for potassium ion batteries
HUANG Tao, PENG Da-chun, CHEN Zui, XIA Xiao-hong, CHEN Yu-xi, LIU Hong-bo
, doi: 10.1016/S1872-5805(21)60069-0
摘要(335) HTML(178) PDF(27)
摘要:
Biomorphic hard carbon recently attracted widely interest as anode materials for potassium ion batteries (PIBs) owing to their high reversible capacity, but high preparation cost and poor cycle stability significantly hinder its practical application. In this study, coconut shell-derived hard carbon (CSHC) was prepared from waste biomass coconut shell using a one-step carbonization method, which was further used as anode materials for potassium ion batteries. The effects of carbonization temperature on the microstructure and electrochemical properties of the CSHC materials were investigated by X-ray diffraction, nitrogen adsorption-desorption isotherms, Raman spectroscopy, scanning electron microscope, transmission electron microscope, and cyclic voltammetry, etc. The results suggested that the coconut shell hard carbon carbonized at 1 000 °C (CSHC-10) possessed suitable graphite microcrystallines size, pore structure and surface defect content, which exhibited the best electrochemical performance. Specifically, CSHC-10 presented a high reversible specific capacity of 254 mAh·g−1 at 30 mA·g−1 with an initial Coulombic efficiency of 75.0%, and the capacity retention was 87.5% after 100 cycles and 75.9% after 400 cycles at 100 mA·g−1. The CSHC with high capacity and good cycling stability demonstrates to be an excellent potassium storage material. Biomorphic hard carbon recently attracted widely interest as anode materials for potassium ion batteries (PIBs) owing to their high reversible capacity, but high preparation cost and poor cycle stability significantly hinder its practical application. In this study, coconut shell-derived hard carbon (CSHC) was prepared from waste biomass coconut shell using a one-step carbonization method, which was further used as anode materials for potassium ion batteries. The effects of carbonization temperature on the microstructure and electrochemical properties of the CSHC materials were investigated by X-ray diffraction, nitrogen adsorption-desorption isotherms, Raman spectroscopy, scanning electron microscope, transmission electron microscope, and cyclic voltammetry, etc. The results suggested that the coconut shell hard carbon carbonized at 1 000 °C (CSHC-10) possessed suitable graphite microcrystallines size, pore structure and surface defect content, which exhibited the best electrochemical performance. Specifically, CSHC-10 presented a high reversible specific capacity of 254 mAh·g−1 at 30 mA·g−1 with an initial Coulombic efficiency of 75.0%, and the capacity retention was 87.5% after 100 cycles and 75.9% after 400 cycles at 100 mA·g−1. The CSHC with high capacity and good cycling stability demonstrates to be an excellent potassium storage material.
Rational construction of Co-loaded ceramic composites by recycling gangue for microwave absorption
LI Guo-min, SHI Shu-ping, ZHU Bao-shun, LIANG Li-ping, ZHANG Ke-wei
, doi: 10.1016/S1872-5805(21)60064-1
摘要(83) HTML(42) PDF(50)
摘要:
In the context of sustainable development, tackling the severe solid wastes pollution has become extremely urgent. Herein, the solid waste gangue was successfully recycled to synthesize the ceramic based composite microwave absorbing materials decorated with Co particles through a novel synthesis method. The magnetic Co particles were uniformly loaded in the ceramic matrix by the pelletizing process with gangue and Co2+ following by the in situ carbothermal reaction, and the Co content in ceramic composites can be precisely controlled by adjusting the Co2+ concentration. Furthermore, compared with gangue, the obtained composites displayed optimized performance, the minimum reflection loss value reached −48.2 dB and the effective absorbing band was measured to be 4.3 GHz with the coating thickness of 1.5 mm, which is mainly attributed to the enhanced magnetic loss and multiple interface polarization. Such innovative design of recycling gangue in this work can effectively realize the resource utilization of gangue, which is also beneficial for the low-cost and light-weight of microwave absorbing materials as well. In the context of sustainable development, tackling the severe solid wastes pollution has become extremely urgent. Herein, the solid waste gangue was successfully recycled to synthesize the ceramic based composite microwave absorbing materials decorated with Co particles through a novel synthesis method. The magnetic Co particles were uniformly loaded in the ceramic matrix by the pelletizing process with gangue and Co2+ following by the in situ carbothermal reaction, and the Co content in ceramic composites can be precisely controlled by adjusting the Co2+ concentration. Furthermore, compared with gangue, the obtained composites displayed optimized performance, the minimum reflection loss value reached −48.2 dB and the effective absorbing band was measured to be 4.3 GHz with the coating thickness of 1.5 mm, which is mainly attributed to the enhanced magnetic loss and multiple interface polarization. Such innovative design of recycling gangue in this work can effectively realize the resource utilization of gangue, which is also beneficial for the low-cost and light-weight of microwave absorbing materials as well.
Electrochemical Fabrication of Ultrafine g-C3N4 Quantum Dots as Hydrogen Evolution Reaction Catalyst
YANG Na-na, CHEN Zhi-gang, ZHAO Zhi-gang, CUI Yi
, doi: 10.1016/S1872-5805(21)60045-8
摘要(428) HTML(247) PDF(32)
摘要:
Benefiting from their high concentration of in-plane nitrogen element, superior chemical/thermal stability, tunable electronic band structure and environmental friendly feature, graphite-like carbon nitride (g-C3N4) as a new promising metal-free material has drawn numerous attention in photo-/electric-catalysis. Comparing to the regulation of band structure in photocatalysis, the deliberately synthesis of g-C3N4 electrocatalysts is mainly focused on the construction of catalytic sites and the modulation of the charge transfer kinetics. Herein, this work reports a rapid method for synthesizing ultrafine g-C3N4 quantum dots (QDs) via electrochemical exfoliation using Al3+ ions. The uniform g-C3N4 QDs with smaller lateral dimension and thickness are collected due to the higher charge density and stronger electrostatic forces of Al3+ ions in the lattice of host materials as compared to the conventional univalent alkali cations. The as-obtained g-C3N4 QDs exhibit average lateral dimension and thickness of 3.5 nm and 1.0 nm, respectively, as determined by the TEM and AFM measurements. Also, the presence of the rich C/N defects is verified by the UV-vis spectra. Encouragingly, the ultrafine g-C3N4 QDs exhibit superior hydrogen evolution reaction (HER) performance with an ultra-low onset-potential closely approaching to 0 V, and a low overpotential of 208 mV at 10 mA/cm2, as well as a remarkably low Tafel slope (52 mV·dec-1) in acidic electrolyte. Taking the fabrication of the ultrafine g-C3N4 QDs with rich C/N defects as an example, this work provides a simple and feasible way to exfoliate 2D layered materials into low-dimensional nanomaterials towards highly-efficient electrocatalysis, as well as the exploration of their fascinating physic-chemical properties. Benefiting from their high concentration of in-plane nitrogen element, superior chemical/thermal stability, tunable electronic band structure and environmental friendly feature, graphite-like carbon nitride (g-C3N4) as a new promising metal-free material has drawn numerous attention in photo-/electric-catalysis. Comparing to the regulation of band structure in photocatalysis, the deliberately synthesis of g-C3N4 electrocatalysts is mainly focused on the construction of catalytic sites and the modulation of the charge transfer kinetics. Herein, this work reports a rapid method for synthesizing ultrafine g-C3N4 quantum dots (QDs) via electrochemical exfoliation using Al3+ ions. The uniform g-C3N4 QDs with smaller lateral dimension and thickness are collected due to the higher charge density and stronger electrostatic forces of Al3+ ions in the lattice of host materials as compared to the conventional univalent alkali cations. The as-obtained g-C3N4 QDs exhibit average lateral dimension and thickness of 3.5 nm and 1.0 nm, respectively, as determined by the TEM and AFM measurements. Also, the presence of the rich C/N defects is verified by the UV-vis spectra. Encouragingly, the ultrafine g-C3N4 QDs exhibit superior hydrogen evolution reaction (HER) performance with an ultra-low onset-potential closely approaching to 0 V, and a low overpotential of 208 mV at 10 mA/cm2, as well as a remarkably low Tafel slope (52 mV·dec-1) in acidic electrolyte. Taking the fabrication of the ultrafine g-C3N4 QDs with rich C/N defects as an example, this work provides a simple and feasible way to exfoliate 2D layered materials into low-dimensional nanomaterials towards highly-efficient electrocatalysis, as well as the exploration of their fascinating physic-chemical properties.
Coal-based graphene as a promoter of TiO2 for photocatalytic degradation of organic dyes
LIU Guo-yang, LI Ke-ke, JIA Jia, ZHANG Ya-ting
, doi: 10.1016/S1872-5805(21)60047-1
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摘要:
A reduced graphene oxide (H-rGO)/TiO2-composite (H-TiO2@rGO) as a catalyst for photocatalytic degradation of rhodamine B (Rh B) and methyl orange (MO) was prepared by hydrothermal treating a dispersant of TiO2 nanoparticles with sizes of 5-10 nm and GO obtained by the Hummers method from coal-based graphite in water. Compared with the M-TiO2@GO and M-TiO2@rGO composites by a wet mixing method, results indicated that the TiO2 nanoparticles in H-TiO2@rGO were uniformly decorated on both sides of rGO sheet, forming a stacked-sheet structure while apparent aggregation of TiO2 nanoparticles was found in both M-TiO2@GO and M-TiO2@rGO. Therefore, H-rGO@TiO2 had the highest catalytic activity towards degradation of Rh B and MO under visible light irradiation among the three, where the incorporation of rGO into TiO2 helps to narrow the band gap of TiO2, inhibit the recombination rate of electron–hole pairs and provide conductive networks for electron transfer. A reduced graphene oxide (H-rGO)/TiO2-composite (H-TiO2@rGO) as a catalyst for photocatalytic degradation of rhodamine B (Rh B) and methyl orange (MO) was prepared by hydrothermal treating a dispersant of TiO2 nanoparticles with sizes of 5-10 nm and GO obtained by the Hummers method from coal-based graphite in water. Compared with the M-TiO2@GO and M-TiO2@rGO composites by a wet mixing method, results indicated that the TiO2 nanoparticles in H-TiO2@rGO were uniformly decorated on both sides of rGO sheet, forming a stacked-sheet structure while apparent aggregation of TiO2 nanoparticles was found in both M-TiO2@GO and M-TiO2@rGO. Therefore, H-rGO@TiO2 had the highest catalytic activity towards degradation of Rh B and MO under visible light irradiation among the three, where the incorporation of rGO into TiO2 helps to narrow the band gap of TiO2, inhibit the recombination rate of electron–hole pairs and provide conductive networks for electron transfer.
Isolated Cobalt Sites Confined in Graphene Matrix for Highly Efficient CO2 Reduction Reactions
ZHANG Hui-nian, WANG Hui-qi, JIA Su-ping, CHANG Qin, LI Ning, LI Ying, SHI Xiao-lin, LI Zi-yuan, HU Sheng-liang
, doi: 10.1016/S1872-5805(21)60061-6
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摘要:
Developing highly selective, economical and stable catalysts for electrochemical converting CO2 into value-added carbon products to mitigate both CO2 emission and energy crisis is still challenging. Here, we report an efficient and robust electrocatalyst for CO2 reduction reaction (CO2RR) by embedding single-atom CoN4 active sites into graphene matrix. These highly dispersed CoN4 sites show an extraordinary CO2RR activity, with a high CO Faradaic efficiency of nearly 95% at −0.76 V (vs. RHE) and remarkable durability. The corresponding overpotential is 0.65 V. Our finding could pave the way for the design of high-efficiency electrocatalyst for CO2RR at the atomic scale. Developing highly selective, economical and stable catalysts for electrochemical converting CO2 into value-added carbon products to mitigate both CO2 emission and energy crisis is still challenging. Here, we report an efficient and robust electrocatalyst for CO2 reduction reaction (CO2RR) by embedding single-atom CoN4 active sites into graphene matrix. These highly dispersed CoN4 sites show an extraordinary CO2RR activity, with a high CO Faradaic efficiency of nearly 95% at −0.76 V (vs. RHE) and remarkable durability. The corresponding overpotential is 0.65 V. Our finding could pave the way for the design of high-efficiency electrocatalyst for CO2RR at the atomic scale.
A wet granulation to dense graphite particles for high volumetric lithium-ion storage
ZHANG Jia-peng, WANG Deng-ke, ZHANG Li-hui, LIU Hai-yan, LIU Zhao-bin, XING Tao, MA Zhao-kun, CHEN Xiao-hong, SONG Huai-he
, doi: 10.1016/S1872-5805(21)60051-3
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摘要:
Graphite is the most widely used anode material for lithium ion batteries (LIBs), and increasing the sphericity and density of graphite is the main way to further improve energy density of LIBs. Herein, we report a simple preparation of high tap-density graphite granules by the high-shear wet granulation. In this way, we densified two kinds of graphite into granule, namely wet-granulation graphitic onion-like carbon (WG-GOC) and wet-granulation artificial graphite (WG-AG). It is found that, compared with the original graphite before granulation, the tap density of WG-GOC increases by ca.34%, and WG-AG increases by ca.44%. Therefore, when as the anode of LIBs,, the volumetric capacities of WG-GOC and WG-AG have increased by ca.35% and ca.55%, respectively, at the current density of 50 mA g−1. In addition, the rate performance of WG-GOC also has been significantly improved. The volumetric capacity of WG-GOC increased by 169.1% at the current density of 2000 mA g−1. The significant improvement of electrochemical performance benefits from the higher tap density of the prepared graphite granules. Hence, we developed a facile wet-granulation to prepare high tap-density graphite anodes, which conducive to the development of high volumetric capacity. Graphite is the most widely used anode material for lithium ion batteries (LIBs), and increasing the sphericity and density of graphite is the main way to further improve energy density of LIBs. Herein, we report a simple preparation of high tap-density graphite granules by the high-shear wet granulation. In this way, we densified two kinds of graphite into granule, namely wet-granulation graphitic onion-like carbon (WG-GOC) and wet-granulation artificial graphite (WG-AG). It is found that, compared with the original graphite before granulation, the tap density of WG-GOC increases by ca.34%, and WG-AG increases by ca.44%. Therefore, when as the anode of LIBs,, the volumetric capacities of WG-GOC and WG-AG have increased by ca.35% and ca.55%, respectively, at the current density of 50 mA g−1. In addition, the rate performance of WG-GOC also has been significantly improved. The volumetric capacity of WG-GOC increased by 169.1% at the current density of 2000 mA g−1. The significant improvement of electrochemical performance benefits from the higher tap density of the prepared graphite granules. Hence, we developed a facile wet-granulation to prepare high tap-density graphite anodes, which conducive to the development of high volumetric capacity.
Preparation of high-performance anthracite-based graphite anode materials and their lithium storage properties
LI Yuan, TIAN Xiaodong, SONG Yan, YANG Tao, WU Shijie, LIU Zhanjun
, doi: 10.1016/S1872-5805(21)60057-4
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摘要:
In this study, cost-effective anthracite and industrial silicon powder were used as precursor and catalyst, respectively, to prepare graphite with various structure, during which the catalytic mechanism was analyzed. The results demonstrate that the as-obtained sample with 5% silicon catalyst (G-2800-5%) exhibits the best overall lithium storage performance. In detail, G-2800-5% display the best graphite structure with graphitization degree of 91.5%. As anode materials, a high reversible capacity of 369.0 mAh g−1 can be achieved at 0.1 A g−1. Meanwhile, the reversible capacity of 209.0 mAh g−1 can be obtained at the current density of 1 A g−1. It also delivers good cyclic stability with a 92.2% retention after 200 cycles at 0.2 A g−1. The highly developed graphite structure, which is favorable to the formation of stable SEI and reduced lithium ion loss should be responsible for the superior electrochemical performance. In this study, cost-effective anthracite and industrial silicon powder were used as precursor and catalyst, respectively, to prepare graphite with various structure, during which the catalytic mechanism was analyzed. The results demonstrate that the as-obtained sample with 5% silicon catalyst (G-2800-5%) exhibits the best overall lithium storage performance. In detail, G-2800-5% display the best graphite structure with graphitization degree of 91.5%. As anode materials, a high reversible capacity of 369.0 mAh g−1 can be achieved at 0.1 A g−1. Meanwhile, the reversible capacity of 209.0 mAh g−1 can be obtained at the current density of 1 A g−1. It also delivers good cyclic stability with a 92.2% retention after 200 cycles at 0.2 A g−1. The highly developed graphite structure, which is favorable to the formation of stable SEI and reduced lithium ion loss should be responsible for the superior electrochemical performance.
Study on the preparation of MoSi2 modified HfB2-SiC ultra high tem-perature ceramic anti-oxidation coating by liquid phase sintering
REN Xuan-ru, WANG Wei-guang, SUN Ke, HU Yu-wen, XU Lei-hua, FENG Pei-zhong
, doi: 10.1016/S1872-5805(21)60060-4
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摘要:
In this paper, a liquid-phase sintering method was developed by combining in-situ reaction method with slurry method to prepare HfB2-MoSi2-SiC coatings with controllable composition, content and thickness. The effect of MoSi2 content on the oxidation protection behavior of HfB2-MoSi2-SiC composite coating under dynamic aerobic environment at room temperature ~ 1500 ℃ and static constant temperature air at 1500 ℃ was studied, the relative oxygen permeability was used to characterize the oxidation resistance of the coating. The results of dynamic oxidation test at room temperature ~ 1500 ℃ showed that the initial oxidation weight loss of the samples was delayed from 775 ℃ to 821 ℃, and the maximum weight loss rate decreased from 0.9×10−3 mg·cm−2·s−1 to 0.2×10−3 mg·cm−2·s−1 with the increase of MoSi2 content, the lowest relative oxygen permeability was reduced to 12.2%, resulting in the weight loss of the sample from 1.8% to 0.21%. In this paper, the mechanism of MoSi2 enhancing the ability of oxidation protection of the coating is revealed. With the increase of MoSi2 content, the amount of SiO2 glass phase in the coating is increased, and the dispersion of Hf-oxide on the coating surface is promoted, thus, the Hf-Si-O compound glass layer with higher stability can be formed, and the weight loss rate of the sample reduced from 0.46% to 0.08% after 200 h oxidation at 1500 ℃ in constant temperature air. In this paper, a liquid-phase sintering method was developed by combining in-situ reaction method with slurry method to prepare HfB2-MoSi2-SiC coatings with controllable composition, content and thickness. The effect of MoSi2 content on the oxidation protection behavior of HfB2-MoSi2-SiC composite coating under dynamic aerobic environment at room temperature ~ 1500 ℃ and static constant temperature air at 1500 ℃ was studied, the relative oxygen permeability was used to characterize the oxidation resistance of the coating. The results of dynamic oxidation test at room temperature ~ 1500 ℃ showed that the initial oxidation weight loss of the samples was delayed from 775 ℃ to 821 ℃, and the maximum weight loss rate decreased from 0.9×10−3 mg·cm−2·s−1 to 0.2×10−3 mg·cm−2·s−1 with the increase of MoSi2 content, the lowest relative oxygen permeability was reduced to 12.2%, resulting in the weight loss of the sample from 1.8% to 0.21%. In this paper, the mechanism of MoSi2 enhancing the ability of oxidation protection of the coating is revealed. With the increase of MoSi2 content, the amount of SiO2 glass phase in the coating is increased, and the dispersion of Hf-oxide on the coating surface is promoted, thus, the Hf-Si-O compound glass layer with higher stability can be formed, and the weight loss rate of the sample reduced from 0.46% to 0.08% after 200 h oxidation at 1500 ℃ in constant temperature air.
Hierarchical Porous Carbon from lignin-rich residue for High-Performance Supercapacitor
FANG Yan-yan, ZHANG Qian-yu, ZHANG Dong-dong, CUI Li-feng
, doi: 10.1016/S1872-5805(21)60058-6
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摘要:
Designing electrically conductive electrode material with a hierarchical pore structure from abundant raw material remains a significant challenge in the development of energy storage research. In this work, 3D porous carbons with high surface areas are synthesized via high-temperature carbonization and activation. The synthesized activated carbons deliver a specifical capacitance of 280 F g−1 and area-specific capacitance of 1.3 F cm−2 at a current density of 0.5 A g−1. The assembled symmetric supercapacitor can deliver a high energy output (7.7 Wh kg−1 at 5200 W kg−1). Thus, it is demonstrated the repurposing of lignin waste as electrode material can be a feasible resource that goes beyond the limitations of utilizing lignin in low value-added applications. Designing electrically conductive electrode material with a hierarchical pore structure from abundant raw material remains a significant challenge in the development of energy storage research. In this work, 3D porous carbons with high surface areas are synthesized via high-temperature carbonization and activation. The synthesized activated carbons deliver a specifical capacitance of 280 F g−1 and area-specific capacitance of 1.3 F cm−2 at a current density of 0.5 A g−1. The assembled symmetric supercapacitor can deliver a high energy output (7.7 Wh kg−1 at 5200 W kg−1). Thus, it is demonstrated the repurposing of lignin waste as electrode material can be a feasible resource that goes beyond the limitations of utilizing lignin in low value-added applications.
A correlation of the hydrogen evolution reaction activity to the defects formed by the decomposition of doped phosphorus species in carbon nanotubes
AI Jie, LIU Zi-wu, SUN Mao-mao, LIU Ling, WANG Quan-de
, doi: 10.1016/S1872-5805(21)60052-5
摘要(160) HTML(92) PDF(12)
摘要:
The phosphorus-doped carbon materials as one of novel carbon catalysts towards the hydrogen evolution reaction (HER) have attracted considerable attention over the past years. However, the role of C-P species palyed in the HER activity is still not clear up to now. Phosphorus-doped carbon nanotubes (P-CNTs) were prepared by chemical vapor deposition and annealed at 900, 1000 and 1200 ℃ to remove all or parts of phosporus species, resulting in four samples with different proportions of graphite-, pyridine- and pyrrole-like P species. The correlations between their HER activity and the contents of three types of P species were investigated. Results showed that the content of graphite-like P decreased with the annealing temperature and no graphite-like P was retained at 1200℃. The HER activity increased with the annealing temperature and the one annealed at 1200 ℃ had the highest HER activity in an acid medium with an overpotential of 0.266 V at a current density of 10 mA/cm−2. Density functional theory calculations revealed that the pentagon- and nine-membered ring defects formed by the destruction of graphite-P species contributed mainly to the HER activity, which gave a deep insight into the active sites for HER. The phosphorus-doped carbon materials as one of novel carbon catalysts towards the hydrogen evolution reaction (HER) have attracted considerable attention over the past years. However, the role of C-P species palyed in the HER activity is still not clear up to now. Phosphorus-doped carbon nanotubes (P-CNTs) were prepared by chemical vapor deposition and annealed at 900, 1000 and 1200 ℃ to remove all or parts of phosporus species, resulting in four samples with different proportions of graphite-, pyridine- and pyrrole-like P species. The correlations between their HER activity and the contents of three types of P species were investigated. Results showed that the content of graphite-like P decreased with the annealing temperature and no graphite-like P was retained at 1200℃. The HER activity increased with the annealing temperature and the one annealed at 1200 ℃ had the highest HER activity in an acid medium with an overpotential of 0.266 V at a current density of 10 mA/cm−2. Density functional theory calculations revealed that the pentagon- and nine-membered ring defects formed by the destruction of graphite-P species contributed mainly to the HER activity, which gave a deep insight into the active sites for HER.
KOH Treated Mesocarbon Microbeads as High Rate Anode for Potassium-Ion Batteries
XIAO Nan, GUO Hong-da, XIAO Jian, WEI Yi-bo, MA Xiao-qing, ZHANG Xiao-yu, QIU Jie-shan
, doi: 10.1016/S1872-5805(21)60059-8
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摘要:
Graphite is one of the most promising anode materials for potassium-ion batteries (PIBs) due to its low cost and stable discharge plateau. However, its poor rate performance still needs to be improved. Herein, a novel graphitic anode was designed from commercial mesocarbon microbeads (MCMB) by KOH treatment. Through limited oxidation and slight intercalation, an expanded layer with enlarged interlayer spacing formed on the surface of MCMB, by which the K+ diffusion rate was significantly improved. When served as the PIB anode, this modified MCMB delivered a high plateau capacity below 0.25 V (271 mAh g−1), superior rate capability (160 mAh g−1 at 1.0 A g−1), excellent cycling stability (about 184 mAh g−1 after 100 cycles at 0.1 A g−1), and high initial coulombic efficiency with carboxymethyl cellulose as binder (79.2%). This work provides a facile strategy to prepare graphitic materials with superior potassium storage property. Graphite is one of the most promising anode materials for potassium-ion batteries (PIBs) due to its low cost and stable discharge plateau. However, its poor rate performance still needs to be improved. Herein, a novel graphitic anode was designed from commercial mesocarbon microbeads (MCMB) by KOH treatment. Through limited oxidation and slight intercalation, an expanded layer with enlarged interlayer spacing formed on the surface of MCMB, by which the K+ diffusion rate was significantly improved. When served as the PIB anode, this modified MCMB delivered a high plateau capacity below 0.25 V (271 mAh g−1), superior rate capability (160 mAh g−1 at 1.0 A g−1), excellent cycling stability (about 184 mAh g−1 after 100 cycles at 0.1 A g−1), and high initial coulombic efficiency with carboxymethyl cellulose as binder (79.2%). This work provides a facile strategy to prepare graphitic materials with superior potassium storage property.
A sustainable strategy to prepare porous carbons with tailored pores from shrimp shell for use as the supercapacitor electrode materials
Gao Feng, Xie Ya-qiao, Zang Yun-hao, ZHOU Gang, QU Jiang-ying, WU Ming-bo
, doi: 10.1016/S1872-5805(21)60019-7
摘要(50) HTML(26) PDF(4)
摘要:
Highly efficient synthesis of nitrogen-doped carbons with different porous structures is reported using shrimp shell as the carbon and nitrogen source, and its CaCO3 component as the hard template and the activator. The content of CaCO3 in shrimp shell can be tuned easily in the range of 0-100% by leaching with an acetic acid solution for different times. CaO derived from decomposition of CaCO3 acts as the activator and template to tailor the pore sizes of the carbons. CO2 derived from decomposition of CaCO3 also plays an activating role. Their specific surface areas, pore volumes, ratios of micropore volumes to total pore volumes can be adjusted in the range of 117.6-1137 m2 g-1, 0.14-0.64 cm3 g-1, and 0-73.4%, respectively. When used as the electrodes of supercapacitor, the porous carbon obtained with a leaching time of 92 min exhibits the highest capacitances of 328 F g-1 at 0.05 A g-1 in a 6 M KOH electrolyte and 619.2 F g-1 at 0.05 A g-1 in a 1 M H2SO4 electrolyte. Its corresponding energy density at a power density of 1470.9 W kg-1 is 26.0 Wh kg-1. This work provides a low cost method for fabricating porous carbons to fulfill the high-value-added use of biomass. Highly efficient synthesis of nitrogen-doped carbons with different porous structures is reported using shrimp shell as the carbon and nitrogen source, and its CaCO3 component as the hard template and the activator. The content of CaCO3 in shrimp shell can be tuned easily in the range of 0-100% by leaching with an acetic acid solution for different times. CaO derived from decomposition of CaCO3 acts as the activator and template to tailor the pore sizes of the carbons. CO2 derived from decomposition of CaCO3 also plays an activating role. Their specific surface areas, pore volumes, ratios of micropore volumes to total pore volumes can be adjusted in the range of 117.6-1137 m2 g-1, 0.14-0.64 cm3 g-1, and 0-73.4%, respectively. When used as the electrodes of supercapacitor, the porous carbon obtained with a leaching time of 92 min exhibits the highest capacitances of 328 F g-1 at 0.05 A g-1 in a 6 M KOH electrolyte and 619.2 F g-1 at 0.05 A g-1 in a 1 M H2SO4 electrolyte. Its corresponding energy density at a power density of 1470.9 W kg-1 is 26.0 Wh kg-1. This work provides a low cost method for fabricating porous carbons to fulfill the high-value-added use of biomass.