Synthesis and characterizations of V2O5/ZnO nanocomposites and enhanced photocatalytic activity

The colloidal carbon spheres were used as "transitional carriers" for the first time to obtain V2O5/ZnO nanocomposites. Each component was prepared by hydrothermal method, and the final product V2O5/ZnO nanocomposites were obtained after sintering in air to remove the colloidal carbon spheres completely. The XRD, TEM and XPS analyses showed the as-prepared samples were composed by wurtzite ZnO and orthorhombic V2O5. Meanwhile, the optical properties of samples were investigated in detail comparing with those of bare ZnO: UV-vis absorption spectra of V2O5/ZnO composites showed their stronger absorption in the visible region, in addition, a significant decrease on emission intensity was observed in the photoluminescence (PL) spectra, which revealed a low combination rate of photogenerated carriers of V2O5/ZnO nanocomposites in this work. Finally, the photocatalytic activities of samples were detected by photodegrading methylene blue (MB) under the simulated solar-driven irradiation. As a result, V2O5/ZnO nanocomposites showed an excellent photocatalytic behavior with a photodegradation rate over 2 times higher than that of bare ZnO, because of its extended visible response and enhanced charge separation efficiency.