花瓣状Fe3O4/Bi2O3复合粒子的制备及光催化活性∗

摘要

In this paper,Fe3 O4 particles prepared from co-precipitation method were used as seed to prepare Fe3 O4/Bi2 O3 composite particles through hydrothermal synthesis.XPS and XRD varied that as-prepared composite particles contained Fe3 O4 and Bi2 O3 .FESEM images showed that the composite particles were spherical shape and flowerlike hierarchical structures.The synthetic conditions of composite particles were investigated in detail. The optional condition wasm(Bi (NO3)3· 5H2O)/m(Fe3O4)was 1.9 g∶0.2 g.Water was used as reactive medium and best temperature was 160 ℃.The Fe3 O4/Bi2 O3 composite particles exhibited high degradation (95.4%)of RhB under visible light.The catalyst can be reused more than 6 times with assistance of an exterior magnet.%用共沉淀法制备的 Fe3 O4纳米粒子作为种子,通过水热法获得了微米尺寸的 Fe3 O4/Bi2 O3复合粒子.X射线衍射和X光电子能谱表征结果说明复合粒子是由Fe3 O4和 Bi2 O3组成.扫描电子显微镜照片表明复合粒子形貌基本呈规则球形,并且具有花瓣状的三维多级结构.以罗丹明B的催化降解实验为模型考察了不同反应组成、不同反应介质、不同反应温度条件下制备的复合粒子的催化活性.结果表明,当反应条件中m(Bi(NO3)3·5H2O)/m(Fe3O4)为1．9 g∶0．2 g,水作反应介质在160℃时,所制备的复合粒子催化活性最高,对罗丹明 B 的降解率达95．4％.降解完成后,用磁铁吸附,Fe3 O4/Bi2 O3很快从体系中分离,可以重新催化降解罗丹明B,实现磁场控制的循环催化.实验发现,Fe3 O4/Bi2 O3经6次循环利用后,对罗丹明B的降解率仍达88．5％.