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

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 H-2 production rate of 2600 mu mol 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 H-2 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 H-2 production.