Novel Approach To Enhance Photosensitized Degradation of Rhodamine B under Visible Light Irradiation by the Zn_xCd_(1-x)S/TiO_2 Nanocomposites

摘要

In order to exploit efficient photosensitizers with appropriate electronic states to enhance the transfer of electrons, Zna.Cdj.xS/TiO_2 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 spectros-copy, electron spin resonance, and photoluminescence techniques. The results showed that the composite of the two inorganic semiconductors largely enhanced the photosensitized degradation of rhodamine B (RhB) under visible light irradiation (420 nm < X < 800 nm). These photocatalytic reactions were driven mainly by the light absorption of RhB molecules and to a lesser extent by the excitation of Zn*Cdj_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 Zn^Cd^S and TiO_2. Such a heterogeneous photocatalytic reaction has much significance in the degradation of organic pollutants in ordinary photocatalysis.