Highly Efficient Photocatalytic Hydrogen Production over PdS@CdS+ZnS(en)0.5 Photocatalyst under Visible Light Irradiation

Abstract

A new photocatalyst, CdS+ZnS(en)0.5 (Cd/Zn = 6:4), was prepared by a simple mechanical mixing method and characterized by various techniques including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of CdS+ZnS(en)0.5 was evaluated for hydrogen production from an aqueous solution under visible light. PdS-loaded CdS+ZnS(en)0.5 exhibited an efficient H2 production rate of 2600 μmol h–1 g–1, which was higher than that observed with PdS-loaded CdS and Cd0.6Zn0.4S solid solution catalysts. The apparent quantum yield at 405 nm was 23%. Furthermore, PdS@CdS+ZnS(en)0.5 showed good stability for prolonged H2 production reactions. It was proposed that enhancement of hole and electron transfer by PdS and ZnS(en)0.5 contributed to the high activity of this photocatalyst for H2 production.