Ultraviolet-assisted preparation of mesoporous WO3/reduced graphene oxide composites: superior interfacial contacts and enhanced photocatalysis

Abstract

In this paper, we report the synthesis, characterization, and photocatalysis of a novel composite, composed of high-ordered mesoporous WO₃ (m-WO₃) and reduced graphene oxide (RGO). The composite was systematically characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, N₂ adsorption–desorption and UV-visible diffuse reflectance spectroscopy techniques. The superior contact between two moieties in the composites facilitates the charge carrier separation and the evolution of oxygen. Under visible light irradiation, the amount of oxygen evolution from the optimized photocatalyst containing ca. 6 wt% RGO reached 437.3 μmol g⁻¹, which was 5.1 times as high as that from m-WO₃. The enhancement of photocatalytic activity could be ascribed to the fact that RGO acts herein as a solid-state electron mediator, promoting the charge transportation and separation, as well as suppressing the electron–hole recombination in the composite. This study might provide a prototype for constructing a novel photocatalytic system by hybridizing graphene with a mesoporous semiconductor for solar energy conversion.