通过液相还原法成功制备了石墨烯负载纳米铁镍复合材料,该材料可高效快速地吸附水中的2,4-二氯酚(2,4-DCP)并对其进行脱氯.微观形貌分析结果表明,粒径为80~150nm的球形Fe/Ni纳米颗粒成功插入石墨烯片层,并主要分布在石墨烯片层边缘和褶皱处,Fe/Ni颗粒团聚现象明显减少,更多活性位点暴露出来.XRD分析和FTIR分析表明,纳米零价铁(nZVI)通过Fe-O键成功嵌入石墨烯(rGO)中,且Fe/Ni纳米颗粒结晶度较差,外围包覆有无定形的铁氧化物沉淀.探讨了不同制备条件如碳铁比、镍化率、氧化石墨烯(GO)还原程度对材料去除2,4-二氯酚(2,4-DCP)性能的影响.综合考虑材料制备成本及对2,4-DCP的吸附脱氯性能,Fe/Ni@rGO复合材料的最优制备条件为:石墨烯与Fe质量比1∶2,镍负载率5%,硼氢化钠与铁盐的物质的量比为5∶1.研究表明5种材料对2,4-DCP的去除率遵循如下顺序:Fe/Ni@rGO复合材料>Fe/Ni>Fe@rGO复合材料>石墨烯>nZVI.储存稳定性试验和循环试验表明,与Fe/Ni双金属相比,Fe/Ni@rGO材料具有稳定的反应活性和较高的重复利用价值.研究结果表明Fe/Ni@rGO复合材料对2,4-DCP的去除为吸附和脱氯协同作用的结果.
Reduced graphene oxide supported Fe/Ni nanocomposites were prepared for the rapid and effective adsorption and dechlorination of 2,4-dichlorophenol(2,4-DCP)by using liquid phase reduction method.The morphological characterization showed that the spherical Fe/Ni bimetallic nanoparticles with the size of 80~150nm were successfully inserted into the graphene sheets and mainly distributed at the edges and folds of the graphene sheets.The agglomeration of Fe/Ni nanoparticles decreased significantly.XRD patterns and FTIR analysis showed nZVI nanoparticles were successfully embedded into graphene through Fe-O bond,Fe/Ni bimetallic nanoparticles had poor crystallinity and amorphous iron oxide which covered the outer layer of nanoparticles.The effects of different preparation conditions such as carbon iron ratio,nickel loading and reduction degree of graphene oxide on the removal of 2,4-DCP were discussed.The optimum preparation conditions of the Fe/Ni@rGO composites are as follows:the mass ratio of graphene to Fe is 1∶2,the Ni loading is 5%,and the molar ratio of NaBH4to Fe2+is 5∶1.The adsorption and dechlorination perfermance of 2,4-DCP by nZVI,Fe/Ni,Fe@rGO composites and Fe/Ni@rGO composites were compared and analyzed.The results showed that the removal efficiency of 2,4-DCP by five materials followed the sequence:Fe/Ni@rGOcomposites>Fe/Ni>rGO>Fe@rGOcomposites>nZVI.However,the cycle test and storage stability test showed:compared with Fe/Ni bimetallic,Fe/Ni@rGO composites had stable reactivity activity and high reruse value.The results demonstrated the removal mechanism of 2,4-DCP by Fe/Ni@rGO composites was the synergistic effect of adsorption and dechlorination.