A PW12/Bi2WO6 composite photocatalyst for enhanced visible light photocatalytic degradation of organic dye pollutants

Abstract

A novel PW₁₂/Bi₂WO₆ composite photocatalyst has been successfully prepared by a facile and effective approach, where PW₁₂ denotes the Keggin-type polyoxometalate H₃PW₁₂O₄₀, and the as-prepared photocatalyst was characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoelectrochemical measurements. The photocatalytic activity of the PW₁₂/Bi₂WO₆ composite photocatalyst was evaluated by using a model reaction of the visible light photocatalytic degradation of rhodamine B (RhB). Under visible light, the PW₁₂/Bi₂WO₆ photocatalyst exhibited a remarkable performance improvement in the photocatalytic degradation of RhB, as compared with pure Bi₂WO₆. The PW₁₂/Bi₂WO₆ composite exhibited high photocatalytic activity with an RhB degradation ratio of >99% in 4 hours, which is almost 2 times as much as that of pure Bi₂WO₆. The action mechanism of the enhanced photocatalytic performance has also been revealed. The introduction of PW₁₂ can efficiently enhance the photocatalytic activity of Bi₂WO₆, because of increasing the efficiency of charge separation and restraining the fast electron–hole recombination in Bi₂WO₆.