Polyacrylonitrile modified partially reduced graphene oxide composites for the extraction of Hg(II) ions from polluted water
Polyacrylonitrile modified partially reduced graphene oxide composites for the extraction of Hg(II) ions from polluted water
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DOI：
10.1007/s10853-021-05797-2
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发表时间：
2021-02-01
影响因子：
4.5
通讯作者：
El-Shall, M. Samy
中科院分区：
文献类型：
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作者：
Awad, Fathi S.;AbouZied, Khaled M.;El-Shall, M. Samy
采用原位乳液聚合法在乙二胺官能化部分还原氧化石墨烯(PAN-PRGO)表面接枝了聚丙烯腈纳米粒子(PAN-PRGO)，并用(4%NaOH，20min)(HPAN-PRGO)对复合材料聚合物链上的氰基进行了部分水解，进一步修饰了纳米石墨烯的表面含胺基、氨基二胺和羧基。通过FTIR、UV-Vis、拉曼光谱、X射线衍射仪、扫描电子显微镜、透射电子显微镜和XPS分析比较了所制备的复合材料的性能和形貌。结果表明，通过乙二胺修饰的氧化石墨烯纳米片上的游离氨基与丙烯腈(AN)的氰基反应，在氨化氧化石墨烯纳米片表面接枝了聚丙烯腈纳米颗粒。对得到的HPAN-PRGO复合材料与汞(II)离子的络合性能进行了评价。考察了HPAN-PRGO对HPAN-PRGO萃取Hg2+的影响，考察了初始pH、Hg2+初始浓度、吸附剂用量和接触时间对HPAN-PRGO萃取Hg2+的影响。吸附实验表明，HPAN-PRGO对Hg(II)具有较高的亲和力。在pH为5时，HPAN-PRGO对Hg(II)离子的最大吸附容量为324.0 mg/g。当HPAN-PRGO的浓度达到50ppm时，HPAN-PRGO对Hg(II)的脱除效率达到100%，并且吸附速度非常快，在15min内对HPAN-PRGO的脱色率超过80.0%，在800ppm时对Q(E)的脱除在1.5h内达到100.0%。Langmuir等温线模型和准二级动力学模型与实际数据吻合较好。吸附前后HPAN-PRGO的XPS分析揭示了汞与胺、羧基之间的络合吸附机理。经过6次吸附-脱附循环后，HPAN-PRGO的吸附容量仍能保持90.0%以上。这些结果证实了HPAN-PRGO在去除废水中的汞(II)方面具有优异的性能。
Polyacrylonitrile nanoparticles grafted on ethylene diamine functionalized partially reduced graphene oxide (PAN-PRGO) was prepared via in situ emulsion polymerization and was further modified to contain amidoxime, amdinoethylene diamine, and carboxylic groups on the surface of the graphene nanosheets via partial hydrolysis of the nitrile groups on the polymer chains of the composite using (4% NaOH, 20 min) (HPAN-PRGO). The properties and morphologies of the prepared composites were compared through FTIR, UV-Vis, Raman spectra, XRD, SEM, TEM, and XPS analysis. The results revealed that polyacrylonitrile nanoparticles were grafted on the surface of the aminated graphene oxide nanosheets via the reaction between the free amino groups of the ethylene diamine modified graphene oxide nanosheets and nitrile groups of acylonitrile (AN). The obtained HPAN-PRGO composite was evaluated for its chelating property with Hg(II) ions. The effect of initial pH, initial concentration of the Hg(II), adsorbent dose, and contact time on the extraction of Hg(II) ions using HPAN-PRGO were investigated. The adsorption experiments indicated that HPAN-PRGO exhibits higher affinity toward Hg(II). The maximum uptake capacity for the extraction of Hg(II) ions on HPAN-PRGO was 324.0 mg/g at pH 5. The HPAN-PRGO shows a 100% removal of Hg(II) at concentrations up to 50 ppm, and the adsorption is exceptionally rapid showing more than 80.0% removal within 15 min and 100.0% of q(e) within 1.5 h at 800 ppm concentration. The Langmuir isotherm model and pseudo-second-order kinetic model have showed good fitness with the practical data. The XPS analysis of HPAN-PRGO before and after adsorption revealed the chelation adsorption mechanism between mercury and amine, amide, amidoxime, and carboxylic groups. After six adsorption-desorption cycles, the HPAN-PRGO could retain more than 90.0% of its original adsorption capacity. These results confirmed that HPAN-PRGO has exceptional performance for the removal of Hg(II) from wastewater.[GRAPHICS].