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碳包覆磁性纳米粒子吸波机制及研究进展
李红盛, 吴爱民, 曹暾, 黄昊
, doi: 10.1016/S1872-5805(22)60624-3
摘要(134) HTML(6) PDF(7)
摘要:
电磁波通讯技术的快速发展,为信息高效传输提供了极大便利,但随之而来高频电子辐射问题日益严重,电磁波吸收材料成为解决电磁辐射的关键。开发“薄、轻、宽、强”的高性能电磁波吸收材料是目前吸波领域研究的重点和热点。本文主要依据传输线理论,介绍了吸波材料的隐身机理,同时总结了吸波材料的制备方法。重点阐述了碳包覆磁性纳米粒子微波隐身材料的研究进展,并讨论了该类吸波材料的未来应用前景以及发展趋势,最后对碳包覆磁性纳米隐身材料的应用以及研发方向提出了几点建议。 电磁波通讯技术的快速发展,为信息高效传输提供了极大便利,但随之而来高频电子辐射问题日益严重,电磁波吸收材料成为解决电磁辐射的关键。开发“薄、轻、宽、强”的高性能电磁波吸收材料是目前吸波领域研究的重点和热点。本文主要依据传输线理论,介绍了吸波材料的隐身机理,同时总结了吸波材料的制备方法。重点阐述了碳包覆磁性纳米粒子微波隐身材料的研究进展,并讨论了该类吸波材料的未来应用前景以及发展趋势,最后对碳包覆磁性纳米隐身材料的应用以及研发方向提出了几点建议。
Advanced design strategies of multi-dimensional structured carbon materials for high-performance Zn-air batteries
YING Jia-ping, ZHENG Dong, MENG Shi-bo, YIN Rui-lian, DAI Xiao-jing, FENG Jin-xiu, WU Fang-Fang, SHI Wen-hui, CAO Xie-hong
, doi: 10.1016/S1872-5805(22)60623-1
摘要(36) HTML(15) PDF(7)
摘要:
Zn-air batteries (ZABs) featuring high safety, low-cost, high specific capacity and environmentally friendliness have attracted intensive attention and emerged as a hot spot in energy storgae devices. However, the sluggish kinetics of oxygen evolution/reduction reactions (OER/ORR) at the air electrode and the non-negligible dendritic growth at the anode have hindered the large scale applications of ZABs. Carbon materials with low-cost, good electrical conductivity, chemical stability and bifunctional OER/ORR activities have been widely studied for ZABs in the past few years. This review begins with the basic working principle of ZABs, followed by the introduction of various carbon materials which focuses on their roles and superiorities in the applications of ZABs. This review also discusses the essential roles of multi-dimensional carbon materials as major components of ZABs, i.e., air electrodes, zinc anode and separators, in improving performance of ZABs. Finally, the perspectives on the future direction of carbon materials towards ZAB performance enhancement are explored. Zn-air batteries (ZABs) featuring high safety, low-cost, high specific capacity and environmentally friendliness have attracted intensive attention and emerged as a hot spot in energy storgae devices. However, the sluggish kinetics of oxygen evolution/reduction reactions (OER/ORR) at the air electrode and the non-negligible dendritic growth at the anode have hindered the large scale applications of ZABs. Carbon materials with low-cost, good electrical conductivity, chemical stability and bifunctional OER/ORR activities have been widely studied for ZABs in the past few years. This review begins with the basic working principle of ZABs, followed by the introduction of various carbon materials which focuses on their roles and superiorities in the applications of ZABs. This review also discusses the essential roles of multi-dimensional carbon materials as major components of ZABs, i.e., air electrodes, zinc anode and separators, in improving performance of ZABs. Finally, the perspectives on the future direction of carbon materials towards ZAB performance enhancement are explored.
生物质碳材料在金属锂负极中的应用
刘奥, 刘铁峰, 袁华栋, 王垚, 刘育京, 罗剑敏, 佴建威, 陶新永
, doi: 10.1016/S1872-5805(22)60620-6
摘要(43) HTML(17) PDF(3)
摘要:
金属锂具有超高理论容量和最低还原电位,被认为是高能量密度电池负极材料的“圣杯”。然而,由于金属锂无宿主、锂枝晶不可控生长、固态电解质界面膜(SEI膜)不稳定以及“死锂”累积等一系列问题,严重制约着金属锂负极的实用化进程。生物质碳材料具有高机械强度、高导电性、高比表面积和良好的化学稳定性等特性,是金属锂宿主材料的理想候选者之一。本文综述了近年来利用生物碳材料构建金属锂沉积骨架的研究进展。通过讨论生物质碳材料的结构、孔隙大小、孔隙率及亲锂基团修饰等对抑制金属锂枝晶生长,构筑循环稳定金属锂负极的影响,总结生物质碳材料的合理设计和应用,提出了生物质碳材料未来发展的趋势以及所面临的挑战。 金属锂具有超高理论容量和最低还原电位,被认为是高能量密度电池负极材料的“圣杯”。然而,由于金属锂无宿主、锂枝晶不可控生长、固态电解质界面膜(SEI膜)不稳定以及“死锂”累积等一系列问题,严重制约着金属锂负极的实用化进程。生物质碳材料具有高机械强度、高导电性、高比表面积和良好的化学稳定性等特性,是金属锂宿主材料的理想候选者之一。本文综述了近年来利用生物碳材料构建金属锂沉积骨架的研究进展。通过讨论生物质碳材料的结构、孔隙大小、孔隙率及亲锂基团修饰等对抑制金属锂枝晶生长,构筑循环稳定金属锂负极的影响,总结生物质碳材料的合理设计和应用,提出了生物质碳材料未来发展的趋势以及所面临的挑战。
选择透过性石墨烯基薄膜在海水淡化领域的应用
高祎甫, 王瑶, 周栋, 吕伟, 康飞宇
, doi: 10.1016/S1872-5805(22)60618-8
摘要(94) HTML(49) PDF(16)
摘要:
以石墨烯为代表的二维材料因其优异且易于调控的选择透过性,被广泛用于制备具有纳米孔或纳米通道的薄膜,在物质分离特别是海水淡化领域表现出广阔的应用前景。本文综述了石墨烯及其衍生物,包括单层石墨烯、多孔石墨烯和氧化石墨烯,在海水淡化领域的研究进展与应用。在对石墨烯的本征属性概述的基础上,分别讨论了具有一维纳米孔的多孔石墨烯薄膜和具有二维纳米通道的层状氧化石墨烯薄膜的离子输运与选择透过特性。着重分析了不同制备工艺及其对石墨烯基薄膜选择透过性的影响,石墨烯基薄膜对多种溶液的选择透过性及其调控方法和机理,以及石墨烯基薄膜在海水淡化领域的应用及其现有局限性。最后,对本领域未来的发展前景进行展望。 以石墨烯为代表的二维材料因其优异且易于调控的选择透过性,被广泛用于制备具有纳米孔或纳米通道的薄膜,在物质分离特别是海水淡化领域表现出广阔的应用前景。本文综述了石墨烯及其衍生物,包括单层石墨烯、多孔石墨烯和氧化石墨烯,在海水淡化领域的研究进展与应用。在对石墨烯的本征属性概述的基础上,分别讨论了具有一维纳米孔的多孔石墨烯薄膜和具有二维纳米通道的层状氧化石墨烯薄膜的离子输运与选择透过特性。着重分析了不同制备工艺及其对石墨烯基薄膜选择透过性的影响,石墨烯基薄膜对多种溶液的选择透过性及其调控方法和机理,以及石墨烯基薄膜在海水淡化领域的应用及其现有局限性。最后,对本领域未来的发展前景进行展望。
Review on H2S selective oxidation over carbon-based materials at low temperature: from pollutant to energy storage materials
SUN Ming-hui, WANG Xu-zhen, ZHAO Zong-bin, QIU Jie-shan
, doi: 10.1016/S1872-5805(22)60622-X
摘要(16) HTML(10) PDF(5)
摘要:
Carbon materials that are widely used for room-temperature selective oxidation of H2S have attracted growing attention in the last few decades. Here, recent development of carbon-based desulfurization catalysts is reviewed, including activated carbon modified by alkaline, porous carbon doped with nitrogen or modified with functional groups, and carbon composites with other species such as alkaline metal oxides. The oxidation mechanisms of H2S upon various catalysts are also discussed, and the important function of carbons in desulfurization are focused, including large specific area, developed porous structure and adjustable surface chemistry. In addition to the catalytic oxidation of H2S, this review also covers the extended application of the spent catalysts, the sulfur/carbon composites, as the sulfur cathode materials for high-performance lithium-sulfur batteries to further achieve the high value-added transformation of sulfur-containing pollutants. Finally, the outlook of carbon-based materials for room-temperature desulfurization and the key challenges of large-scale application has been prospected, which are expected to provide guidance for the development of this technique. Carbon materials that are widely used for room-temperature selective oxidation of H2S have attracted growing attention in the last few decades. Here, recent development of carbon-based desulfurization catalysts is reviewed, including activated carbon modified by alkaline, porous carbon doped with nitrogen or modified with functional groups, and carbon composites with other species such as alkaline metal oxides. The oxidation mechanisms of H2S upon various catalysts are also discussed, and the important function of carbons in desulfurization are focused, including large specific area, developed porous structure and adjustable surface chemistry. In addition to the catalytic oxidation of H2S, this review also covers the extended application of the spent catalysts, the sulfur/carbon composites, as the sulfur cathode materials for high-performance lithium-sulfur batteries to further achieve the high value-added transformation of sulfur-containing pollutants. Finally, the outlook of carbon-based materials for room-temperature desulfurization and the key challenges of large-scale application has been prospected, which are expected to provide guidance for the development of this technique.
研究论文
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)60046-X
摘要(55) HTML(29) PDF(8)
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-on 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 mol L−1 KOH electrolyte and 619.2 F g−1 at 0.05 A g−1 in a 1 mol L−1 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-on 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 mol L−1 KOH electrolyte and 619.2 F g−1 at 0.05 A g−1 in a 1 mol L−1 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.
Synthesis of hierarchical porous carbon with 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
摘要(409) HTML(124) PDF(21)
摘要:
Designing electrically conductive electrode material with a hierarchical pore structure with abundant raw material remains a significant challenge in the field of energy storage. In this work, 3D porous carbons with high surface areas are synthesized via high-temperature carbonization and activation method. The as-prepared activation 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 of 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 with abundant raw material remains a significant challenge in the field of energy storage. In this work, 3D porous carbons with high surface areas are synthesized via high-temperature carbonization and activation method. The as-prepared activation 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 of 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.
Rational design of a 3D CNTs/Ti3C2Tx aerogel modified separator for Li–S batteries to circumvent the shuttle effect and slow redox kinetics of polysulfides
YIN Fei, JIN Qi, ZHANG Xi-tian, WU Li-li
, doi: 10.1016/S1872-5805(21)60085-9
摘要(180) HTML(85) PDF(22)
摘要:
Lithium–sulfur (Li–S) batteries suffer from fast capacity fading and inferior rate performance due to the severe shuttle effect of polysulfides (LiPSs) and slow redox kinetics. To solve these issues, a three-dimensional (3D) CNTs/Ti3C2Tx aerogel was successfully prepared with Ti3C2Tx as the active matrix and CNTs as the conductive pillars, which was 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 incorporation 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, the Li–S cell using the CNTs/Ti3C2Tx aerogel modified separator show a high rate capacity of 1043.2 mAh g–1 up to 2 C and an excellent 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 the severe shuttle effect of polysulfides (LiPSs) and slow redox kinetics. To solve these issues, a three-dimensional (3D) CNTs/Ti3C2Tx aerogel was successfully prepared with Ti3C2Tx as the active matrix and CNTs as the conductive pillars, which was 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 incorporation 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, the Li–S cell using the CNTs/Ti3C2Tx aerogel modified separator show a high rate capacity of 1043.2 mAh g–1 up to 2 C and an excellent cycling life over 800 cycles at 0.5 C with a low capacity decay rate of 0.07% per cycle.
Electrochemical sensing 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 Jiao, LEI Wu
, doi: 10.1016/S1872-5805(21)60087-2
摘要(88) HTML(85) PDF(7)
摘要:
It is known that the electrochemical determination of phenacetin, a widely used analgesic, is challenging for the interference of the electroactive intermediate, acetaminophen. Phenacetin has been proved to be electroactive in 1980s, but its electrochemical determination has not been widely reported. The electrochemical behavior on electrochemical reduced graphene (ERGO) modified electrode was investigated, and its comparison with several nitrogen-doped graphene samples was performed. Results indicate that ERGO possesses higher current response and lower oxidation potential than nitrogen-doped graphene. ERGO modified electrode as a phenacetin sensor has a detection limit of 0.91 μM for phenacetin. The redox mechanism of phenacetin is interfered by electrochemical experiments, and the reactions under different pH values are proposed. Acetaminophen is considered to be the main intermediate and not an interferent in the determination of phenacetin. But phenacetin interfers with the response of acetaminophen obviously, suggesting that simultaneous detection of phenacetin and acetaminophen is not possible. Usual species, such as Cu2+, Al3+, methanol, ethylene glycol, glucose, and ascorbic acid, hardly cause interference in determination of phenacetin. It is known that the electrochemical determination of phenacetin, a widely used analgesic, is challenging for the interference of the electroactive intermediate, acetaminophen. Phenacetin has been proved to be electroactive in 1980s, but its electrochemical determination has not been widely reported. The electrochemical behavior on electrochemical reduced graphene (ERGO) modified electrode was investigated, and its comparison with several nitrogen-doped graphene samples was performed. Results indicate that ERGO possesses higher current response and lower oxidation potential than nitrogen-doped graphene. ERGO modified electrode as a phenacetin sensor has a detection limit of 0.91 μM for phenacetin. The redox mechanism of phenacetin is interfered by electrochemical experiments, and the reactions under different pH values are proposed. Acetaminophen is considered to be the main intermediate and not an interferent in the determination of phenacetin. But phenacetin interfers with the response of acetaminophen obviously, suggesting that simultaneous detection of phenacetin and acetaminophen is not possible. Usual species, such as Cu2+, Al3+, methanol, ethylene glycol, glucose, and ascorbic acid, hardly cause interference in determination of phenacetin.
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(219) HTML(115) PDF(14)
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 °C 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 °C. The HER activity increased with the annealing temperature and the one annealed at 1200 °C 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 °C 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 °C. The HER activity increased with the annealing temperature and the one annealed at 1200 °C 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.
Isolated cobalt sites confined in graphene matrix for highly efficient electrocatalysis CO2 reduction
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
摘要(466) HTML(151) PDF(44)
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.
咖啡渣成型制备生物质炭及其CH4/N2分离性能研究
高雨舟, 徐爽, 王成通, 张雪洁, 刘汝帅, 陆安慧
, doi: 10.1016/S1872-5805(22)60626-7
摘要(4) HTML(3) PDF(1)
摘要:
本文以咖啡渣为原料,硅酸钠为粘结剂和造孔剂,通过挤条成型技术制备柱状炭前驱体,经高温炭化活化和碱洗除硅,获得高强度柱状多孔炭吸附剂(CGCs),研究其CH4/N2的吸附分离性能。红外分析结果显示CGC-1.5含有丰富的含氧官能团。CGCs的比表面积和孔容积随着前驱体中硅酸钠含量的增加而增大,其中9 wt%硅酸钠溶液与原料质量比为1.5的样品CGC-1.5的比表面积为527 m2·g−1,总孔容为0.33 cm3·g−1。氮吸附等温线和CO2吸附等温线分析结果表明CGCs含有丰富的微孔、介孔以及(个别样品)大孔,微孔主要集中在0.48 nm左右。在298 K和1 bar条件下CGC-1.5对CH4的平衡吸附量为0.87 mmol·g−1,CH4/N2 (3/7)的IAST分离选择性达到10.3,优于多数生物质基多孔炭固体吸附剂和晶态材料。双组份动态穿透测试结果证实该材料在常压和加压条件均具有优异的CH4/N2动态分离性能,298 K时1.1 bar和5 bar条件下的动态选择性分别达到10.4和17.9,经过10次吸-脱附循环测试,吸附量保持不变。CGC-1.5的机械强度高达123 N·cm−1,具有潜在的工业应用前景。 本文以咖啡渣为原料,硅酸钠为粘结剂和造孔剂,通过挤条成型技术制备柱状炭前驱体,经高温炭化活化和碱洗除硅,获得高强度柱状多孔炭吸附剂(CGCs),研究其CH4/N2的吸附分离性能。红外分析结果显示CGC-1.5含有丰富的含氧官能团。CGCs的比表面积和孔容积随着前驱体中硅酸钠含量的增加而增大,其中9 wt%硅酸钠溶液与原料质量比为1.5的样品CGC-1.5的比表面积为527 m2·g−1,总孔容为0.33 cm3·g−1。氮吸附等温线和CO2吸附等温线分析结果表明CGCs含有丰富的微孔、介孔以及(个别样品)大孔,微孔主要集中在0.48 nm左右。在298 K和1 bar条件下CGC-1.5对CH4的平衡吸附量为0.87 mmol·g−1,CH4/N2 (3/7)的IAST分离选择性达到10.3,优于多数生物质基多孔炭固体吸附剂和晶态材料。双组份动态穿透测试结果证实该材料在常压和加压条件均具有优异的CH4/N2动态分离性能,298 K时1.1 bar和5 bar条件下的动态选择性分别达到10.4和17.9,经过10次吸-脱附循环测试,吸附量保持不变。CGC-1.5的机械强度高达123 N·cm−1,具有潜在的工业应用前景。
Ni(OH)2/石墨相氮化碳/石墨烯三元复合材料的制备及电化学性能
刘斌, 赫文秀, 张永强, 崔金龙
, doi: 10.1016/S1872-5805(22)60625-5
摘要(5) HTML(4) PDF(0)
摘要:
本文通过水热法制备Ni(OH)2/石墨相氮化碳(g-C3N4)/石墨烯(RGO)三元复合材料,研究了Ni(OH)2∶g-C3N4∶RGO质量比对复合材料结构、形貌和电化学性能的影响。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶转换红外光谱(FT-IR)、氮气物理吸脱附、透射电子显微镜(TEM)等测试手段表征材料的表面微观结构和还原程度,采用循环伏安(CV)、恒流充放电(GCD)及电化学交流阻抗(EIS)测试复合材料的电化学性能。结果表明:当Ni(OH)2∶g-C3N4∶RGO=16∶1∶1(质量比)时三元复合材料为三维片层空间互相交错结构,氧化峰和还原峰的电位差ΔE为0.218 V。当电流密度为1 A/g时,复合材料的比电容为516.9 F/g,充放电3000次循环后,容量保持率达74.3%,显示出良好的电化学性能。 本文通过水热法制备Ni(OH)2/石墨相氮化碳(g-C3N4)/石墨烯(RGO)三元复合材料,研究了Ni(OH)2∶g-C3N4∶RGO质量比对复合材料结构、形貌和电化学性能的影响。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶转换红外光谱(FT-IR)、氮气物理吸脱附、透射电子显微镜(TEM)等测试手段表征材料的表面微观结构和还原程度,采用循环伏安(CV)、恒流充放电(GCD)及电化学交流阻抗(EIS)测试复合材料的电化学性能。结果表明:当Ni(OH)2∶g-C3N4∶RGO=16∶1∶1(质量比)时三元复合材料为三维片层空间互相交错结构,氧化峰和还原峰的电位差ΔE为0.218 V。当电流密度为1 A/g时,复合材料的比电容为516.9 F/g,充放电3000次循环后,容量保持率达74.3%,显示出良好的电化学性能。
碳纳米管复合纤维素水凝胶的界面光热净水性能研究
王雪, 孙洋, 赵冠宇, 王旭珍, 邱介山
, doi: 10.1016/S1872-5805(22)60621-8
摘要(65) HTML(17) PDF(5)
摘要:
基于低温溶剂法从大宗农林废弃物玉米芯中提取的纤维素,耦合具有优异吸光性能的碳纳米管(CNTs),构筑复合纤维素水凝胶(CNTs-CH),利用纤维素凝胶的高保水性、可降解性,以及碳纳米管的高效光热转换能力、优良的力学性能和生物相容性,将其用于太阳能驱动界面水蒸发净化领域。考察了吸光材料CNTs的不同添加量对CNTs-CH复合水凝胶的太阳能吸收率、机械性能及界面光热水蒸发效率的影响。最优条件下,CNTs添加量仅需0.2 wt.%,此CNTs-CH复合纤维素水凝胶的平均蒸发速率可达到~1.52 kg m−2 h−1,太阳能-蒸汽转换效率约92%;在海水中连续蒸发8 h,蒸发速率可保持在1.37 kg m−2 h−1左右,且无积盐现象,净化水质远高于WHO和EPA对饮用水的标准,说明CNTs-CH抗盐性能较强。此外,CNTs-CH水凝胶在强酸/碱性水溶液体系、染料废水和重金属离子污染水体中的蒸发速率可维持在1.30-1.40 kg m−2 h−1,太阳能-蒸汽效率可达到80-86%,对污染物及盐分截留率高达99.9%,蒸发效果稳定,说明CNTs-CH光热蒸发器在海水淡化和工业废水净化回用领域有广阔的应用前景。 基于低温溶剂法从大宗农林废弃物玉米芯中提取的纤维素,耦合具有优异吸光性能的碳纳米管(CNTs),构筑复合纤维素水凝胶(CNTs-CH),利用纤维素凝胶的高保水性、可降解性,以及碳纳米管的高效光热转换能力、优良的力学性能和生物相容性,将其用于太阳能驱动界面水蒸发净化领域。考察了吸光材料CNTs的不同添加量对CNTs-CH复合水凝胶的太阳能吸收率、机械性能及界面光热水蒸发效率的影响。最优条件下,CNTs添加量仅需0.2 wt.%,此CNTs-CH复合纤维素水凝胶的平均蒸发速率可达到~1.52 kg m−2 h−1,太阳能-蒸汽转换效率约92%;在海水中连续蒸发8 h,蒸发速率可保持在1.37 kg m−2 h−1左右,且无积盐现象,净化水质远高于WHO和EPA对饮用水的标准,说明CNTs-CH抗盐性能较强。此外,CNTs-CH水凝胶在强酸/碱性水溶液体系、染料废水和重金属离子污染水体中的蒸发速率可维持在1.30-1.40 kg m−2 h−1,太阳能-蒸汽效率可达到80-86%,对污染物及盐分截留率高达99.9%,蒸发效果稳定,说明CNTs-CH光热蒸发器在海水淡化和工业废水净化回用领域有广阔的应用前景。
Oxygen-incorporated carbon nitride porous nanosheets for highly efficient photoelectrocatalytic CO2 reduction to formate
WANG Hong-zhi, ZHAO Yue-zhu, YANG Zhong-xue, BI Xin-ze, WANG Zhao-liang, WU Ming-bo
, doi: 110.1016/S1872-5805(22)60619-X
摘要(19) HTML(7) PDF(1)
摘要:
Recycling CO2 as a renewable carbon source for the production of high-value fuels and chemicals has drawn global attention lately. Among the available CO2-recycling ways, photoelectrocatalytic (PEC) CO2 reduction reaction (CO2RR) is one of the most realistic and attractive choice, which can be realized effectively under simulated sunlight illumination and low overpotential. In the work, oxygen-incorporated carbon nitride (CN) porous nanosheets are synthesized successfully as photoanode and Bi2CuO4 as photocathode to realize the PEC CO2 reduction to formate. The electrical conductivity and the photoelectric response of prepared CN were tailored successfully by changing the oxygen source. In detail, the oxygen from the precursor could improve the conductivity because of the more negative electronegativity. However, the oxygen from the calcination atmosphere showed side effects on the photoelectric response by changing the energy band structure. Under the optimal conditions, the photocurrent density is 587 μA cm−2 and the activity of PEC CO2 reduction to formate is 273.56 µmol cm−2 h−1 (nearly 19 times than that of the conventional sample). What’s more, the CN samples showed excellent stability with a constant photocurrent for 24 hours. The present work provides a new avenue to achieve efficient PEC CO2 reduction to formate, and can be expanded to other PEC reaction by coupling different cathode catalysts. Recycling CO2 as a renewable carbon source for the production of high-value fuels and chemicals has drawn global attention lately. Among the available CO2-recycling ways, photoelectrocatalytic (PEC) CO2 reduction reaction (CO2RR) is one of the most realistic and attractive choice, which can be realized effectively under simulated sunlight illumination and low overpotential. In the work, oxygen-incorporated carbon nitride (CN) porous nanosheets are synthesized successfully as photoanode and Bi2CuO4 as photocathode to realize the PEC CO2 reduction to formate. The electrical conductivity and the photoelectric response of prepared CN were tailored successfully by changing the oxygen source. In detail, the oxygen from the precursor could improve the conductivity because of the more negative electronegativity. However, the oxygen from the calcination atmosphere showed side effects on the photoelectric response by changing the energy band structure. Under the optimal conditions, the photocurrent density is 587 μA cm−2 and the activity of PEC CO2 reduction to formate is 273.56 µmol cm−2 h−1 (nearly 19 times than that of the conventional sample). What’s more, the CN samples showed excellent stability with a constant photocurrent for 24 hours. The present work provides a new avenue to achieve efficient PEC CO2 reduction to formate, and can be expanded to other PEC reaction by coupling different cathode catalysts.
Construction of Flexible, Integrated Rechargeable Li Battery Based on the Coaxial Carbon/Quaternary Oxide Composite Anode
ZOU Yi-ming, SUN Chang-chun, LI Shao-wen, BAI Miao, DU Yu-xuan, ZHANG Min, XU Fei, MA Yue
, doi: 10.1016/S1872-5805(22)60617-6
摘要(25) HTML(9) PDF(5)
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The flexible battery configuration relies on the electrode's design ingenuity with the elaborate control over structural integrity, compositional consistency and shape adaption subjected with mechanical loadings. Herein, we develop coaxial arrays of quaternary oxide nanocrystallines on carbon cloth (CC@FeNiMnO4-600), with the additional capability of tailoring the N-doped carbon coating that derived from the quasi-gel tri-copolymer in the anode design. CC@FeNiMnO4-600 anode displays a large areal capacity of ~1.40 mAh cm−2 and satisfactory cycling efficiency (1 mA cm−2) by galvanostatic evaluation; the compatible interfacial electrochemistry and mechanical flexibility could be also coherently achieved even upon the contact with the solid polymer electrolyte, namely the few-layer boron nitride modified polyethylene oxide. This promising performance could be ascribed to the synergistic components, i.e., the excellent balance of the kinetic active oxide anode with the mechanical flexible coaxial architecture; additionally, the intimate PEOǁanode interfacial binding enables the facile and continuous ion transport, promoting the practical use of the solid-state prototype in the wearable electronics. The flexible battery configuration relies on the electrode's design ingenuity with the elaborate control over structural integrity, compositional consistency and shape adaption subjected with mechanical loadings. Herein, we develop coaxial arrays of quaternary oxide nanocrystallines on carbon cloth (CC@FeNiMnO4-600), with the additional capability of tailoring the N-doped carbon coating that derived from the quasi-gel tri-copolymer in the anode design. CC@FeNiMnO4-600 anode displays a large areal capacity of ~1.40 mAh cm−2 and satisfactory cycling efficiency (1 mA cm−2) by galvanostatic evaluation; the compatible interfacial electrochemistry and mechanical flexibility could be also coherently achieved even upon the contact with the solid polymer electrolyte, namely the few-layer boron nitride modified polyethylene oxide. This promising performance could be ascribed to the synergistic components, i.e., the excellent balance of the kinetic active oxide anode with the mechanical flexible coaxial architecture; additionally, the intimate PEOǁanode interfacial binding enables the facile and continuous ion transport, promoting the practical use of the solid-state prototype in the wearable electronics.
Nitrogen doped hollow-shaped porous carbon fiber derived from polyacrylonitrile for Li-S batteries
NIU Jing-yi, JING De-qi, ZHANG Xing-hua, SU Wei-guo, ZHANG Shou-chun
, doi: 10.1016/S1872-5805(22)60615-2
摘要(41) HTML(20) PDF(2)
摘要:
Hollow-shaped porous carbon fiber for Li-S batteries electrodes is prepared by KOH activation using polyacrylonitrile (PAN) as the precursor. The obtained porous carbon fiber has a high specific surface area of 2491 m2·g−1 and a large pore volume of 1.22 cm3·g−1. And it exhibits an initial specific capacity of 330 mAh·g−1 at current density of 1 C. To further improve electrochemical performance, the fiber precursor is modified using hydrazine hydrate to prepare nitrogen doped hollow-shaped porous carbon fiber. The modified fiber shows a specific surface area of 1690 m2·g−1, a pore volume of 0.84 cm3·g−1 and a high nitrogen content of 8.81 at%. Since nitrogen doping can increase the polarity and adsorption capacity, the initial specific capacity of the nitrogen doped porous carbon fiber can be increased to 420 mAh·g−1 at current density of 1 C. Hollow-shaped porous carbon fiber for Li-S batteries electrodes is prepared by KOH activation using polyacrylonitrile (PAN) as the precursor. The obtained porous carbon fiber has a high specific surface area of 2491 m2·g−1 and a large pore volume of 1.22 cm3·g−1. And it exhibits an initial specific capacity of 330 mAh·g−1 at current density of 1 C. To further improve electrochemical performance, the fiber precursor is modified using hydrazine hydrate to prepare nitrogen doped hollow-shaped porous carbon fiber. The modified fiber shows a specific surface area of 1690 m2·g−1, a pore volume of 0.84 cm3·g−1 and a high nitrogen content of 8.81 at%. Since nitrogen doping can increase the polarity and adsorption capacity, the initial specific capacity of the nitrogen doped porous carbon fiber can be increased to 420 mAh·g−1 at current density of 1 C.
Flexible hard carbon microspheres/MXene film as high performance anode for sodium-ion storage
CAO Hai-liang, YANG Liang-tao, ZHAO Min, LIU Pei-zhi, GUO Chun-li, XU Bing-she, GUO Jun-jie
, doi: 10.1016/S1872-5805(22)60616-4
摘要(32) HTML(20) PDF(6)
摘要:
Hard carbon is considered as the most promising negative electrode for sodium-ion batteries, but the volume change during sodiation/desodiation limits the cycle life. Herein, a binder- and current-collector-free hard carbon microspheres/MXene film electrode is constructed and its sodium storage properties are also studied. The monodispersed hard carbon microspheres (HCS) were prepared using Shanxi aged vinegar as a liquid carbon source. In addition, two-dimensional Ti3C2Tx MXene nanosheets were used as multifunctional conductive binders to fabricate flexible electrode. Remarkably, benefiting from the three-dimensional conductive network, the Ti3C2Tx bonded HCS film electrode shows high capacity of 346 mAh g−1, excellent rate performance and outstanding cycle stability over 1000 cycles. The remarkable electrochemical properties indicate that such film is a very promising flexible electrode for next-generation flexible secondary rechargeable batteries. Hard carbon is considered as the most promising negative electrode for sodium-ion batteries, but the volume change during sodiation/desodiation limits the cycle life. Herein, a binder- and current-collector-free hard carbon microspheres/MXene film electrode is constructed and its sodium storage properties are also studied. The monodispersed hard carbon microspheres (HCS) were prepared using Shanxi aged vinegar as a liquid carbon source. In addition, two-dimensional Ti3C2Tx MXene nanosheets were used as multifunctional conductive binders to fabricate flexible electrode. Remarkably, benefiting from the three-dimensional conductive network, the Ti3C2Tx bonded HCS film electrode shows high capacity of 346 mAh g−1, excellent rate performance and outstanding cycle stability over 1000 cycles. The remarkable electrochemical properties indicate that such film is a very promising flexible electrode for next-generation flexible secondary rechargeable batteries.
Co/N-doped carbon catalyst derived from metal-organic framework (ZIF-8@ZIF-67) for efficient oxygen reduction reaction (ORR)
ZHANG Ya-ting, LI Si-yi, ZHANG Na-na, LIN Gang, WANG Rui-qi, YANG Meng-nan, LI Ke-ke
, doi: 10.1016/S1872-5805(22)60609-7
摘要(76) HTML(43) PDF(12)
摘要:
Carbon-based oxygen reduction reaction (ORR) catalysts are considered a potential substitution for the expensive platinum-based ORR catalysts in the aspect of energy conversion. Recently, metal and nitrogen codoped carbon materials (M-N-C) formed by transition metals and nitrogen-doped carbon materials have attracted much attention from researchers due to their low cost and excellent activity. Herein, a cobalt- and nitrogen-codoped porous carbon material (Co-N@CNT-C800) is prepared via a simple one-step pyrolysis method by well-designed carambola-shaped MOFs (ZIF-8@ZIF-67). The obtained Co-N@CNT-C800 consists of many carbon nanotubes (CNTs) with substantial Co doping and N doping. A large surface area (428 m2·g−1) and a favorable three-dimensional structure are also observed. The obtained Co-N@CNT-C800 exhibits excellent performance in half-wave potential and limited current density in alkaline media with a value of 0.841 V and 5.07 mA·cm−2, respectively. In addition, Co-N@CNT-C800 also shows excellent electrochemical stability and methanol tolerance compared with commercial Pt/C materials. The proposed strategy inspires a effective way to fabricate low cost and high activity electrocatalysts used for energy conversion. Carbon-based oxygen reduction reaction (ORR) catalysts are considered a potential substitution for the expensive platinum-based ORR catalysts in the aspect of energy conversion. Recently, metal and nitrogen codoped carbon materials (M-N-C) formed by transition metals and nitrogen-doped carbon materials have attracted much attention from researchers due to their low cost and excellent activity. Herein, a cobalt- and nitrogen-codoped porous carbon material (Co-N@CNT-C800) is prepared via a simple one-step pyrolysis method by well-designed carambola-shaped MOFs (ZIF-8@ZIF-67). The obtained Co-N@CNT-C800 consists of many carbon nanotubes (CNTs) with substantial Co doping and N doping. A large surface area (428 m2·g−1) and a favorable three-dimensional structure are also observed. The obtained Co-N@CNT-C800 exhibits excellent performance in half-wave potential and limited current density in alkaline media with a value of 0.841 V and 5.07 mA·cm−2, respectively. In addition, Co-N@CNT-C800 also shows excellent electrochemical stability and methanol tolerance compared with commercial Pt/C materials. The proposed strategy inspires a effective way to fabricate low cost and high activity electrocatalysts used for energy conversion.
Incorporation of nano-TiO2 into multichannel carbon fibers for enhanced adsorption of polysulfides in room temperature sodium-sulfur batteries
YE Xin, LI Zhi-qi, SUN Hao, WU Ming-xia, AN Zhong-xun, PANG Yue-peng, YANG Jun-he, ZHENG Shi-you
, doi: 10.1016/S1872-5805(22)60607-3
摘要(39) HTML(22) PDF(10)
摘要:
With the rapid development of electric vehicles and large-scale power grids, lithium-ion batteries will inevitably face the dilemma that the limited energy density fails to meet the growing demand and the cost keeps rising. Room temperature sodium-sulfur (RT Na-S) batteries, which have the potential to replace lithium-ion batteries, have become the focus of attention. However, the challenging problem of poor cycling performance arising from “shuttle effect” of the reaction intermediate sodium polysulfides needs to be addressed. Herein, we report the incorporation of nano-TiO2 into multichannel carbon fibers (TiO2@MCCFs) to stabilize sulfur and realize high performance RT Na-S batteries. The TiO2@MCCFs are prepared by electrospinning and heat treatment, which then act as matrix to fabricate S/TiO2@MCCFs cathode through melt-diffusion method. The addition of TiO2 nanoparticles enhances the affinity for polysulfides while promoting the conversion of polysulfides to lower order products. As a result, the obtained S/TiO2@MCCFs cathode with around 54% S achieves improved electrochemical properties with the specific capacity of 445.1 mAh g−1 after 100 cycles at 0.1 A g−1 as well as nearly 100% Coulombic efficiency. Even at 2 A g−1, the cathode still exhibits a capacity of 300.5 mAh g−1 after 500 cycles, demonstrating excellent rate and cycling performance. The enhanced effect of the incorporation of nano-TiO2 on the adsorption capacity of carbon-based materials is verified by combining characterization and theoretical calculations. This work provides a new path to construct high performance RT Na-S battery cathodes by theoretical and experimental aspects, respectively. With the rapid development of electric vehicles and large-scale power grids, lithium-ion batteries will inevitably face the dilemma that the limited energy density fails to meet the growing demand and the cost keeps rising. Room temperature sodium-sulfur (RT Na-S) batteries, which have the potential to replace lithium-ion batteries, have become the focus of attention. However, the challenging problem of poor cycling performance arising from “shuttle effect” of the reaction intermediate sodium polysulfides needs to be addressed. Herein, we report the incorporation of nano-TiO2 into multichannel carbon fibers (TiO2@MCCFs) to stabilize sulfur and realize high performance RT Na-S batteries. The TiO2@MCCFs are prepared by electrospinning and heat treatment, which then act as matrix to fabricate S/TiO2@MCCFs cathode through melt-diffusion method. The addition of TiO2 nanoparticles enhances the affinity for polysulfides while promoting the conversion of polysulfides to lower order products. As a result, the obtained S/TiO2@MCCFs cathode with around 54% S achieves improved electrochemical properties with the specific capacity of 445.1 mAh g−1 after 100 cycles at 0.1 A g−1 as well as nearly 100% Coulombic efficiency. Even at 2 A g−1, the cathode still exhibits a capacity of 300.5 mAh g−1 after 500 cycles, demonstrating excellent rate and cycling performance. The enhanced effect of the incorporation of nano-TiO2 on the adsorption capacity of carbon-based materials is verified by combining characterization and theoretical calculations. This work provides a new path to construct high performance RT Na-S battery cathodes by theoretical and experimental aspects, respectively.
An Innovative and Efficient Preparation of Mesocarbon Microbeads by The Delayed Capillary Breakup Method and Their Electrochemical Performance
DONG Si-lin, YANG Jian-xiao, CHANG Sheng-kai, SHI Kui, LIU Yue, ZOU Jia-ling, LI Jun
, doi: 10.1016/S1872-5805(22)60606-1
摘要(41) HTML(29) PDF(8)
摘要:
An innovative and efficient preparation method of mesocarbon microbeads (MCMBs) was developed based on the dripping behavior and rheological theory of pitch during the melt-spinning process, named as the delayed capillary breakup (DCB) method. In this work, the MCMBs were prepared by the DCB method with different receiving solvents (water or tetrahydrofuran (THF)), and their microstructure evolutions were compared systematically. Moreover, the MCMBs were further activated with KOH at 750 °C or graphitized at 2800 °C to prepare the A-MCMBs or G-MCMBs, and their electrochemical performance as electrode materials for electronic double layer capacitors (EDLC) or lithium-ion batteries (LIB) was investigated, respectively. The results showed that both MCMB-W prepared from water and MCMB-T prepared from THF had great spherical structure with the size of 1~2 μm. In addition, A-MCMB-T had a high specific surface area (1391 m2 g−1), micropore volume (0.55 cm3 g−1) and mesopore volume (0.24 cm3 g−1), exhibiting 30% higher specific capacitance than the original material, and its capacitance retention was also significantly improved when it was used as an electrode material for EDLC. Moreover, G-MCMB-T had high graphitization degree (0.895) and orderly lamellar structure, which demonstrated high specific capacity of 353.5 mAh g−1 after 100 cycles at 100 mA g−1 when it was used as an electrode material for LIB. Therefore, this work proposed and verified a new preparation method of MCMBs, which could provide a strategy for designing and developing traditional energy storage materials. An innovative and efficient preparation method of mesocarbon microbeads (MCMBs) was developed based on the dripping behavior and rheological theory of pitch during the melt-spinning process, named as the delayed capillary breakup (DCB) method. In this work, the MCMBs were prepared by the DCB method with different receiving solvents (water or tetrahydrofuran (THF)), and their microstructure evolutions were compared systematically. Moreover, the MCMBs were further activated with KOH at 750 °C or graphitized at 2800 °C to prepare the A-MCMBs or G-MCMBs, and their electrochemical performance as electrode materials for electronic double layer capacitors (EDLC) or lithium-ion batteries (LIB) was investigated, respectively. The results showed that both MCMB-W prepared from water and MCMB-T prepared from THF had great spherical structure with the size of 1~2 μm. In addition, A-MCMB-T had a high specific surface area (1391 m2 g−1), micropore volume (0.55 cm3 g−1) and mesopore volume (0.24 cm3 g−1), exhibiting 30% higher specific capacitance than the original material, and its capacitance retention was also significantly improved when it was used as an electrode material for EDLC. Moreover, G-MCMB-T had high graphitization degree (0.895) and orderly lamellar structure, which demonstrated high specific capacity of 353.5 mAh g−1 after 100 cycles at 100 mA g−1 when it was used as an electrode material for LIB. Therefore, this work proposed and verified a new preparation method of MCMBs, which could provide a strategy for designing and developing traditional energy storage materials.
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(78) HTML(54) PDF(9)
摘要:
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
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摘要:
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(41) HTML(19) PDF(3)
摘要:
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
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摘要:
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.
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(622) HTML(292) PDF(50)
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
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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.
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.
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.
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
摘要(405) HTML(141) PDF(37)
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.