Preparations and Photocatalytic Properties of Visible-Light-Active Zinc Ferrite-Doped TiO₂ Photocatalyst

Abstract

A visible-light-active TiO2/ZnFe2O4 photocatalyst was prepared by liquid catalytic phase transformation and the sol−gel method. The diffuse reflection spectra results show that TiO2/ZnFe2O4 photocatalyst can absorb visible light. The photocatalytic experimental result demonstrates that TiO2/ZnFe2O4 powder can effectively photodegrade methyl orange under visible light irradiation. The analysis of XRD indicated that the highly dispersed ZnFe2O4 nanoparticles prevented the formation of the rutile phase to some extent. A transmission electron microscope was used to characterize the structure of the photocatalyst, indicating that the ZnFe2O4 nanoparticles are highly dispersed among TiO2 nanoparticles. In TiO2/ZnFe2O4 photocatalyst, the relatively narrow bandgap ZnFe2O4 as the light-absorbing semiconductor and the wide bandgap titanium oxide formed a coupled semiconductor system resulting in an efficient primary charge separation and photocatalytic activity under visible light irradiation. The effect of calcination temperature and the amount of ZnFe2O4 on photocatalytic activity of TiO2/ZnFe2O4 was also investigated.