Ionic liquid-assisted hydrothermal synthesis of Bi2WO6–reduced graphene oxide composites with enhanced photocatalytic activity

Abstract

In order to develop highly efficient visible-light-driven photocatalysts, bismuth tungstate (Bi₂WO₆) was incorporated with reduced graphene oxide (RGO) via an ionic liquid-assisted hydrothermal process. The photocatalytic activities of the as-prepared samples were evaluated by photocatalytic degradation of a rhodamine B aqueous solution under visible light irradiation. Compared with pure Bi₂WO₆, all the as-prepared RGO–Bi₂WO₆ composites exhibited significantly enhanced photocatalytic performances for the degradation of rhodamine B. Significantly, the optimum photocatalytic degradation efficiency of RGO–Bi₂WO₆ composites prepared in the presence of the ionic liquid was about 1.9 times higher than that of Bi₂WO₆–RGO composites prepared without using the ionic liquid. The excellent photocatalytic performances of RGO–Bi₂WO₆ composites were correlated with the surface area, light absorption and the separation efficiency of photoinduced electrons and holes. Moreover, the possible mechanism of the enhanced photocatalytic activity for the RGO–Bi₂WO₆ photocatalyst was proposed on the basis of the experimental results.