Preparation of 3D graphene-carbon nanotube-magnetic hybrid aerogels for dye adsorption
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摘要:
将ZnCl2、NiCl2·6H2O、FeCl2·4H2O和FeCl3·6H2O分别加入氧化石墨烯和碳纳米管的悬浮液中,在碱性条件下共沉淀和水中与聚乙烯醇交联后,冷冻干燥制备气凝胶。制备的气凝胶由磁性Ni0.5Zn0.5Fe2O4纳米粒子、氧化石墨烯、碳纳米管和聚乙烯醇组成,不仅具有吸附染料分子的活性位点,而且可通过外加磁场从水中分离。在最佳质量比下,制备的气凝胶对亚甲基蓝具有高的吸附容量(qe=71.03 mg g−1)和中等磁性强度(MS=3.519 emu g−1)。在染料浓度为0.025 mg mL−1的条件下,气凝胶对亚甲基蓝、甲基橙、结晶紫及其相等质量的混合物的去除效率分别为70.1%、4.2%、8.9%和11.1%。该气凝胶重复使用3次后,再生效率仍超过82%。此外,它对生物体无毒,有望用作处理工业废水的吸附剂。
Abstract:Novel hybrid aerogels were prepared by adding ZnCl2, NiCl2·6H2O, FeCl2·4H2O and FeCl3·6H2O to a suspension of equal weights of graphene oxide and oxidized carbon nanotubes, followed by co-precipitation under basic conditions. The aerogels were then crosslinked with polyvinyl alcohol in water and freeze-dried. They consisted of magnetic Ni0.5Zn0.5Fe2O4 nanoparticles, graphene oxide, carbon nanotubes and polyvinyl alcohol, which have active sites that attract dye molecules and could be extracted from water by applying a magnetic field. Using optimum mass ratios of ZnCl2/NiCl2·6H2O/FeCl2·4H2O/FeCl3·6H2O/(graphene oxide+oxidized carbon nanotube) at 6∶6∶12∶12∶1, the hybrid aerogel has a high adsorption capacity of 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 a mixture of equal masses of the three were 70.1%, 4.2%, 8.9% and 11.1%, respectively for the same dye concentration of 0.025 mg mL−1. It could be used for 3 regeneration cycles with a regeneration efficiency of over 82%. It was also not toxic to the living organisms, suggesting that it is a promising adsorbent for treating industrial wastewater.
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Key words:
- Magnetic aerogel /
- Dye removal /
- Graphene /
- Carbon nanotubes /
- Caenorhabditis elegans (C. elegans)
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Table 1. Saturation magnetization (MS), coercivity (HC) and retentivity (MR) at room temperature for the aerogels.
Sample MS (emu g−1) HC (G) MR (emu g−1) F1 2.535 2.181 0.000937 F2 2.808 4.776 0.00203 F3 3.519 8.651 0.00338 F4 4.584 1.498 0.00211 F5 6.029 1.169 0.00237 F6 10.293 1.077 0.00278 Ni0.5Zn0.5Fe2O4 10.696 0.625 0.00252 Table 2. Kinetic parameters for F3 aerogel.
Kinetic models Parameters Value Pseudo first- order qe (mg g−1) 66.87 qe error (%) 5.85 k1 (L min−1) 0.0109 R2 0.9453 Pseudo second-order qe (mg g−1) 84.75 qe error (%) 19.3 k2 (g mg−1 min−1) 0.00016 R2 0.9528 V0 (mg g−1 min−1) 1.15 -
[1] Chen D, Zeng Z, Zeng Y, et al. Removal of methylene blue and mechanism on magnetic γ-Fe2O3/SiO2 nanocomposite from aqueous solution[J]. Water Resources and Industry,2016,15:1-13. doi: 10.1016/j.wri.2016.05.003 [2] Liu C, Liu H, Xu A, et al. In situ reduced and assembled three-dimensional graphene aerogel for efficient dye removal[J]. Journal of Alloys and Compounds,2017,714:522-529. doi: 10.1016/j.jallcom.2017.04.245 [3] Nagelkerke NJD. A note on a general definition of the coefficient of determination[J]. Biometrika,1991,78(3):691-692. doi: 10.1093/biomet/78.3.691 [4] Xu Z, Li X, Teng K, et al. High flux and rejection of hierarchical composite membranes based on carbon nanotube network and ultrathin electrospun nanofibrous layer for dye removal[J]. Journal of Membrane Science,2017,535:94-102. doi: 10.1016/j.memsci.2017.04.029 [5] Ding Y, Tian Z, Li H, et al. Efficient removal of organic dyes using a three-dimensional graphene aerogel with excellent recycling stability[J]. New Carbon Materials,2019,34(4):315-324. doi: 10.1016/S1872-5805(19)30020-4 [6] El-Moselhy MM, Kamal SM. Selective removal and preconcentration of methylene blue from polluted water using cation exchange polymeric material[J]. Groundwater for Sustainable Development,2018,6:6-13. doi: 10.1016/j.gsd.2017.10.001 [7] Tolba GMK, Bastaweesy AM, Ashour EA, et al. Effective and highly recyclable ceramic membrane based on amorphous nanosilica for dye removal from the aqueous solutions[J]. Arabian Journal of Chemistry,2016,9(2):287-296. doi: 10.1016/j.arabjc.2015.05.009 [8] García JR, Sedran U, Zaini MAA, et al. Preparation, characterization, and dye removal study of activated carbon prepared from palm kernel shell[J]. Environmental Science and Pollution Research,2018,25(6):5076-5085. doi: 10.1007/s11356-017-8975-8 [9] Zheng W, Qi T, Zhang Y, et al. Fabrication and characterization of a multi-walled carbon nanotube-based counter electrode for dye-sensitized solar cells[J]. New Carbon Materials,2015,30(5):391-396. doi: 10.1016/S1872-5805(15)60198-6 [10] Shen Y, Zhu X, Zhu L, et al. Synergistic effects of 2D graphene oxide nanosheets and 1D carbon nanotubes in the constructed 3D carbon aerogel for high performance pollutant removal[J]. Chemical Engineering Journal,2017,314:336-346. doi: 10.1016/j.cej.2016.11.132 [11] GAO Feng, QIN Shi-hui, ZANG Yun-hao, et al. Highly efficient formation of Mn3O4-graphene oxide hybrid aerogels for use as the cathode material of high performance lithium ion batteries[J]. New Carbon Materials,2020,35(2):121-130. doi: 10.1016/S1872-5805(20)60479-6 [12] Tran H V, Bui LT, Dinh TT, et al. Graphene oxide/Fe3O4/chitosan nanocomposite: A recoverable and recyclable adsorbent for organic dyes removal. Application to methylene blue[J]. Materials Research Express,2017,4(3):35701. doi: 10.1088/2053-1591/aa6096 [13] Lee B, Lee S, Lee M, et al. Carbon nanotube-bonded graphene hybrid aerogels and their application to water purification[J]. Nanoscale,2015,7(15):6782-6789. doi: 10.1039/C5NR01018G [14] Areerob Y, Cho JY, Jang WK, et al. Enhanced sonocatalytic degradation of organic dyes from aqueous solutions by novel synthesis of mesoporous Fe3O4-graphene/ZnO@SiO2 nanocomposites[J]. Ultrasonics Sonochemistry,2018,41:267-278. doi: 10.1016/j.ultsonch.2017.09.034 [15] Meidanchi A, Akhavan O. Superparamagnetic zinc ferrite spinel–graphene nanostructures for fast wastewater purification[J]. Carbon,2014,69:230-238. doi: 10.1016/j.carbon.2013.12.019 [16] Dai J, Huang T, Tian S, et al. High structure stability and outstanding adsorption performance of graphene oxide aerogel supported by polyvinyl alcohol for waste water treatment[J]. Materials & Design,2016,107:187-197. [17] Zhang L, Wang Z, Xu C, et al. High strength graphene oxide/polyvinyl alcohol composite hydrogels[J]. J Mater Chem,2011,21(28):10399-10406. doi: 10.1039/c0jm04043f [18] Yao W, Geng C, Han D, et al. Strong and conductive double-network graphene/PVA gel[J]. RSC Adv,2014,4(74):39588-39595. doi: 10.1039/C4RA02674H [19] Bai H, Li C, Wang X, et al. A pH-sensitive graphene oxide composite hydrogel[J]. Chem Commun,2000,46(14):2376-2378. [20] K N, Ramana G V, D S, et al. Synthesis of graphene oxide by modified hummers method and hydrothermal synthesis of graphene-NiO nano composite for supercapacitor application[J]. Journal of Material Science & Engineering,2016,05(06):284. [21] Pawelec KM, Husmann A, Best SM, et al. Altering crystal growth and annealing in ice-templated scaffolds[J]. Journal of Materials Science,2015,50(23):7537-7543. doi: 10.1007/s10853-015-9343-z [22] Kong C, Yehye WA, Abd Rahman N, et al. Discovery of potential anti-infectives against Staphylococcus aureus using a Caenorhabditis elegans infection model[J]. BMC Complementary and Alternative Medicine,2014,14(1):4. doi: 10.1186/1472-6882-14-4 [23] Chen L, Li Y, Du Q, et al. High performance agar/graphene oxide composite aerogel for methylene blue removal[J]. Carbohydrate Polymers,2017,155:345-353. doi: 10.1016/j.carbpol.2016.08.047 [24] Liu D, Li J, Sun F, et al. Liquid crystal microphase separation of cellulose nanocrystals in wet-spun PVA composite fibers[J]. RSC Adv,2014,4(58):30784-30789. doi: 10.1039/C4RA04063E [25] Shahriary L, Athawale AA. Graphene oxide synthesized by using modified hummers approach[J]. Int J Renew Energy Environ Eng,2014,2(1):58-63. [26] Chiang Y-C, Lin W-H, Chang Y-C. The influence of treatment duration on multi-walled carbon nanotubes functionalized by H2SO4/HNO3 oxidation[J]. Applied Surface Science,2011,257(6):2401-2410. doi: 10.1016/j.apsusc.2010.09.110 [27] El-Sheikh SM, Rashad MM, Harraz FA. Morphological investigation and magnetic properties of nickel zinc ferrite 1D nanostructures synthesized via thermal decomposition method[J]. Journal of Nanoparticle Research,2013,15(10):1967. doi: 10.1007/s11051-013-1967-9 [28] Wang X, Liu X, Yuan H, et al. Non-covalently functionalized graphene strengthened poly(vinyl alcohol)[J]. Materials & Design,2018,139:372-379. [29] Shahane GS, Kumar A, Arora M, et al. Synthesis and characterization of Ni–Zn ferrite nanoparticles[J]. Journal of Magnetism and Magnetic Materials,2010,322(8):1015-1019. doi: 10.1016/j.jmmm.2009.12.006 [30] Afkhami A, Sayari S, Moosavi R, et al. Magnetic nickel zinc ferrite nanocomposite as an efficient adsorbent for the removal of organic dyes from aqueous solutions[J]. Journal of Industrial and Engineering Chemistry,2015,21:920-924. doi: 10.1016/j.jiec.2014.04.033 [31] Ho Y-S. Review of second-order models for adsorption systems[J]. Journal of Hazardous Materials,2006,136(3):681-689. doi: 10.1016/j.jhazmat.2005.12.043 [32] Sun H, Cao L, Lu L. Magnetite/reduced graphene oxide nanocomposites: One step solvothermal synthesis and use as a novel platform for removal of dye pollutants[J]. Nano Research,2011,4(6):550-562. doi: 10.1007/s12274-011-0111-3 [33] Plazinski W, Dziuba J, Rudzinski W. Modeling of sorption kinetics: the pseudo-second order equation and the sorbate intraparticle diffusivity[J]. Adsorption,2013,19(5):1055-1064. doi: 10.1007/s10450-013-9529-0 [34] Ai L, Zhang C, Chen Z. Removal of methylene blue from aqueous solution by a solvothermal-synthesized graphene/magnetite composite[J]. Journal of Hazardous Materials,2011,192(3):1515-1524. doi: 10.1016/j.jhazmat.2011.06.068 [35] Robati D, Mirza B, Rajabi M, et al. Removal of hazardous dyes-BR 12 and methyl orange using graphene oxide as an adsorbent from aqueous phase[J]. Chemical Engineering Journal,2016,284:687-697. doi: 10.1016/j.cej.2015.08.131 [36] Pei Y, Wang M, Tian D, et al. Synthesis of core–shell SiO2@MgO with flower like morphology for removal of crystal violet in water[J]. Journal of Colloid and Interface Science,2015,453:194-201. doi: 10.1016/j.jcis.2015.05.003 [37] Geng Z, Lin Y, Yu X, et al. Highly efficient dye adsorption and removal: a functional hybrid of reduced graphene oxide–Fe3O4 nanoparticles as an easily regenerative adsorbent[J]. Journal of Materials Chemistry,2012,22(8):3527-3535. doi: 10.1039/c2jm15544c