BiFeO_3空间选择性光化学还原Ag及光催化活性

BiFeO_3 Nanoparticles: Space Selective Photochemical Reduction of Ag and Photocatalytic Activity

采用溶胶-凝胶法和光还原沉积法制备出Ag改性的纳米BiFeO3粒子，对复合材料进行了FESEM、XRD、XPS、FTIR、UV-Vis/DRS等分析和表征。考察了波长365 nm以上的光照下，铁磁性材料的空间选择性光化学反应对复合材料的结构、形貌以及光谱性质的影响。以罗丹明B为模拟污染物，考察了纳米Ag-BiFeO3粒子的可见光光催化活性以及稳定性。结果表明：通过光化学沉积，不仅增强了BiFeO3在200~800 nm光照下的响应，而且抑制了光腐蚀现象， 提高了BiFeO3的稳定性。在波长大于400 nm的光照射12 h后单纯纳米BiFeO3粒子对罗丹明B脱色率约为74%，而Ag-BiFeO3复合材料6 h后约为90%，并且重复使用3次后光催化效果基本不变。

Silver-modified BiFeO3 nanoparticles were prepared by the sol-gel and photodeposition method. The composites were characterized by FESEM, XRD, XPS, FTIR, UV-Vis/DRS. The effect of the space selective photochemical reaction of ferromagnetic material was investigated on structure, morphology and spectral properties of the composites under light irradiation （λ≥365 nm）. The photocatalytic activity of the nanoparticle was tested using rhodamine B as the model reaction under visible-light irradiation. The results show that the modification not only enhances the ultraviolet-visible light response of BiFeO3, but also inhibits the photocorrosion phenomenon of BiFeO3 and improves the stability of the catalyst. The decolorization of rhodamine B is 74% with fresh pure BiFeO3 under visible light within 12 h, however, the decolorization of rhodamine B is about 90% with Ag-BiFeO3 nano-composites within 6 h, and the catalytic performance of Ag-BiFeO3 nano-composites remains almost the same after three cycles.