Efficient photocatalytic degradation of ibuprofen in aqueous solution using novel visible-light responsive graphene quantum dot/AgVO3 nanoribbons

Single crystalline, non-toxicity, and long-term stability graphene quantum dots (GQDs) were modified onto the AgVO3 nanoribbons by a facile hydrothermal and sintering technique which constructs a unique heterojunction photocatalyst. Characterization results indicate that GQDs are well dispersed on the surface of AgVO3 nanoribbons and GQD/AgVO3 heterojunctions are formed, which can greatly promote the separation efficiency of photogenerated electron-hole pairs under visible light irradiation. By taking advantage of this feature, the GQD/AgVO3 heterojunctions exhibit considerable improvement on the photocatalytic activities for the degradation of ibuprofen (IBP) under visible light irradiation as compared to pure AgVO3. The photocatalytic activity of GQD/AgVO3 heterojunctions is relevant with GQD ratio and the optimal activity is obtained at 3 wt% with the highest separation efficiency of photogenerated electron-hole pairs. Integrating the physicochemical and photocatalytic properties, the factors controlling the photocatalytic activity of GQD/AgVO3 heterojunctions are discussed in detail. Moreover, potential photocatalytic degradation mechanisms of IBP via GQD/AgVO3 heterojunctions under visible light are proposed.