镍铜纳米线-氧化石墨烯复合磁性催化剂的制备及其性能

Preparation and Performance of Ni&Cu-Nanowires and Graphene Oxide Composite Magnetic Catalyst for Catalytic Reduction of p-Nitrophenol

相对于贵金属催化剂,催化效率较低和循环使用性能不佳,是限制非贵金属催化剂在处理含硝基芳烃类的有机废水及工业生产对氨基苯酚等多相催化领域应用的关键因素,因此开发高效且可循环使用的非贵金属催化剂是当务之急。采用磁场辅助-液相还原-金属置换法,先在氧化石墨烯(GO)水溶胶体系中自组装制备氧化石墨烯与镍纳米线(Ni-NWs)的原位复合物Ni-NWs@GO,再利用原电池反应于液相条件下在前驱体Ni-NWs@GO的表面通过金属置换负载上活性金属铜(Cu),制备了一种磁性纳米催化剂镍铜纳米线-氧化石墨烯(Ni&Cu-NWs@GO),并以催化还原对硝基苯酚为对氨基苯酚为反应模型考察了其催化性能。结果表明:优化条件下制备的Ni&Cu-NWs@GO复合材料平均直径约为90nm,平均长度大于2μm,比表面积为11.36m^(2)/g;将其用于催化还原对硝基苯酚反应时,催化效率达到98.29%,质量反应速率常数为5.81mg-1·min-1,循环反应十圈后催化反应转化率超过82%,综合性能明显优于参照催化剂(市售雷尼镍)。

Compared with noble metal catalysts,low catalytic efficiency and poor recycling performance are the key factors to restrict non-noble metal catalysts for the treatment of organic wastewater containing p-nitrophenol and industrial production of p-nitroaniline.Therefore,the development of efficient and recyclable non-noble metal catalysts is a top priority mission in the field of heterogeneous catalysis.A magnetic nano-catalyst named as Ni&Cu-NWs@GO was prepared by a magnetic field assisted-liquid phase reduction-metal replacement method.Firstly,a graphene oxide(GO)and Ni Nanowires(Ni-NWs)complex,GO@Ni-NWs was self-assembled in the GO hydrosol system induced by the external magnetic field.Then,Ni&Cu-NWs@GO was prepared by the replacement of copper(Cu)on the surface of Ni-NWs@GO under the condition of liquid phase reaction.Lastly,the nanocatalyst was applied to the catalytic reduction of p-nitrophenol to investigate its heterogeneous catalytic performance.Characterization results showed that it played the key role to prepare Ni&Cu-NWs@GO composite with the action of external magnetic field and pH of the reaction system.The product obtained under optimal conditions was applied to catalyze the reduction of p-nitrophenol,with average diameter of 90nm,average length of greater than 2μm and specific surface area of 11.36m^(2)/g.Catalytic results indicated that its comprehensive performance was obviously better than Raney-Ni,with the catalytic efficiency of 98.29%,the mass reaction rate constant kM of 5.81mg-1·min-1,and the catalytic conversion rate maintaining more than 82% after 10 cycles of the catalytic reaction.