Bi/Fe3O4催化NaBH4还原水中对硝基苯酚

摘要

以磁性Fe3O4为载体负载Bi（NO3）3，再用NaBH4还原Bi3+制备了Bi/Fe3O4催化剂。采用XRD和紫外-可见光谱对催化剂进行表征。考察了Bi负载量、NaBH4加入量和Bi/Fe3O4加入量对Bi/Fe3O4催化NaBH4还原对硝基苯酚（4-NP）效果的影响。表征结果显示：当催化剂中Bi含量较少时，Bi分散良好；当Bi含量较多时，会形成纳米颗粒。实验结果表明：当反应温度为25℃、初始4-NP浓度为4.0 mmol/L时，在Bi负载量为5%（w）、Bi/Fe3O4催化剂加入量为500 mg/L、NaBH4加入量为6.0 g/L的条件下，反应速率常数为0.581 min-1，4-NP的去除率为99.7%；Bi/Fe3O4催化剂稳定性好，重复使用15次后，活性基本不变。%The Bi/Fe3O4 catalyst was prepared by loading Bi(NO3)3 on magnetic Fe3O4 and then reducing Bi3+with NaBH4. The catalyst was characterized by XRD and UV-Vis spectrophotometry. The factors affecting the Bi/Fe3O4-catalyzed reduction of p-nitrophenol(4-NP)with NaBH4 were studied. The characterization results show that Bi can disperse uniformly in the catalyst when the content of Bi is little,vice versa,form nanoparticle. The characterization results show that:Under the conditions of reaction temperature 25℃,initial 4-NP mass concentration 4.0 mmol/L, Bi loading 5%(w),Bi/Fe3O4 catalyst dosage 500 mg/L and NaBH4 dosage 6.0 g/L,the reaction rate constant is 0.581 min-1,and the 4-NP removal rate is 99.7%;The stability of the Bi/Fe3O4 catalyst is good and its activity keeps almost the same after reused for 15 times.