Tsinghua University Beijing, China
Posters & Accepted Abstracts: Res. Rev. J Mat. Sci
Photocatalysis is attracting huge interest by addressing current energy and environmental issues by converting solar light into chemical energy. For this purpose, we investigated the effect of La3+ and Se4+ co-doping on photocatalytic activity of BiFeO3. The BiFeO3 and Bi0.92La0.08FeO3 nanoparticles containing different Se4+ doping contents (BiFe(1-x)SexO3,x= 0.0, 0.02, 0.05) and (Bi0.92La0.08Fe(1-x)SexO3, x = 0.0, 0.02, 0.05, 0.075, 0.1), respectively, were synthesized with double solvent sol-gel route. The co-doped nanoparticles were characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and UV-Vis diffuse reflectance spectroscopy (DRS), and their photocatalytic activity was studied by photocatalytic degradation of Congo red (CR) in aqueous solution under different wavelengths of light illumination. The band-gap of the pure BiFeO3 was significantly decreased from 2.06 eV to 1.94 eV. It was found that the La3+ and Se4+ co-doping significantly affected the photocatalytic performance of pure BiFeO3. Moreover, with the increment of Se4+ doping into Bi0.92La0.08FeO3 up to an optimal value, the photocatalytic activity was maximized. In order to study the photosensitization process, photo-degradation of colorless organic compound (acetophenone) was also observed. On the basis of these experimental results, the enhanced photocatalytic activities of La3+ and Se4+ co-doping could be attributed to the increased optical absorption, the efficient separation and migration of photo-generated charge carriers with the decreased recombination of electron-hole resulting from co-doping effect. The possible photocatalytic mechanism of La3+ and Se4+ co-doped BiFeO3 was critically discussed.