Preparation and Photocatalysis Property of P-N Coupled Photocatalyst CoO/CdS/TiO<sub>2</sub>

In this paper, p-n coupled photocatalyst CoO/CdS/TiO 2 was prepared by method of impregnation. The structure and optical properties of CdS/TiO2 and CoO/CdS/TiO 2 were characterized by XRD, SEM, BET and UV–vis DRS. The photocatalytic activities of the photocatalysts were evaluated by photocatalytic degradation of methyl orange, and the effect of photocorrosion of CdS in CoO/CdS/TiO 2 was investigated by analyzing the cadmium concentration in the supernate collected after photocatalytic reactions. The results showed that p-n coupled photocatalyst CoO/CdS/TiO 2 not only showed higher efficiency in degradation of methyl orange than CdS/TiO 2 , but also exhibited resistance against cadmium leakage under light irradiation. The mechanism of the photocorrosion-delaying by p–n junction was also discussed.