Novel Approach To Enhance Photosensitized Degradation of Rhodamine B under Visible Light Irradiation by the ZnxCd1-xS/TiO2 Nanocomposites

In order to exploit efficient photosensitizers appropriate electronic states to enhance the transfer of electrons ZnxCd1-xS/TiO2 nanocomposites were first synthesized by a simple hydrothermal method. The samples were characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron spin resonance, and photoluminescence techniques. The results showed that the composite of the two inorganic semiconductors largely enhanced the photosensitized degradation of rhodamine (Rh) under visible light irradiation (420 nm < lambda < 800 nm). These photocatalytic reactions were driven mainly by the light absorption of RhB molecules and to a lesser extent by the excitation of ZnxCd1-xS. They were supposed to arise mainly from the electron transferred from the adsorbed dye in its singlet excited state to the conduction band of ZnxCd1-xS and TiO2. Such a heterogeneous photacatalytic reaction has much significance in the degradation of organic pollutants in ordinary photocatalysis.