Enhanced photovoltaic effect of TiO2-based composite ZnFe2O4/TiO2

A TiO2-based composite, ZnFe2O4/TiO2, was prepared with a commercial TiO2 (Degussa P25) and ZnFe2O4 nanopowders using a simple method. The composite was characterized by X-ray diffraction (XRD), UV–vis absorption spectrum, surface photovoltage spectroscopy (SPS) and SEM. The composite presents an enhanced photovoltaic effect compared with the pure TiO2. The trap distributions of TiO2 and ZnFe2O4/TiO2 composite were investigated and the energy levels of TiO2 and ZnFe2O4 were analyzed. The results indicate that the enhancement of photovoltaic effect is mainly due to the increase of photo-generated carrier concentration and improvement of the separation efficiency of photo-generated carriers by the addition of ZnFe2O4.