Bi₂WO₆ quantum dots decorated reduced graphene oxide: Improved charge separation and enhanced photoconversion efficiency

In this study, Bi₂WO₆ quantum dots (QDs) decorating reduced graphene oxide (RGO) sheets were produced by a facile one-step hydrothermal synthesis process, which converts the reactant precursors to Bi₂WO₆ QDs and RGO simultaneously. The Bi ₂WO₆ QDs with a size of 3-5 nm anchored uniformly on the RGO sheets to form RGO-Bi₂WO₆ QDs composites. The RGO sheets not only acted as a supporter and stabilizer for the Bi ₂WO₆ QDs to prevent them from being aggregation but also largely improved the charge separation in the composite material. For this preponderance, the electron lifetime in the RGO-Bi₂WO₆ QDs composites was increased 8-fold compared with that of the pure Bi ₂WO₆ QDs. The much enhanced lifetime improved its performance in environmental purification and photovoltaic conversion under the irradiation of simulated sun light. This work not only provides a principle method to produce graphene-composited multiple metal oxide QDs by one-step process but also a route to obtain efficient functional material for environmental purification and optoelectronic applications.