Synthesis, Characterization and Photocatalytic Activity of TiO2 Film/Bi2O3 Microgrid Heterojunction

TiO2 film modified by Bi2O3 microgrid array was successfully fabricated by using a microsphere lithography method. The structure and morphology of TiO2 film, Bi2O3 film and TiO2 film/Bi2O3 microgrid heterojunction were characterized through X-ray diffraction, atomic force microscopy and scanning electron microscopy. The optical transmittance spectra and the photocatalytic degradation capacity of these samples to rhodamine B were determined via ultraviolet-visible spectroscopy. The results indicated that the coupled system showed higher photocatalytic activity than pure TiO2 and Bi2O3 films under xenon lamp irradiation. The enhancement of the photocatalytic activity was ascribed to the special structure, which could improve the separation of photo-generated electrons and holes, enlarge the surface area and extend the response range of TiO2 film from ultraviolet to visible region.