High-performance photocatalyst based on nanosized ZnO-reduced graphene oxide hybrid for removal of Rhodamine B under visible light irradiation

Nano-sized zinc oxide-reduced graphene oxide (ZnO-RGO) hybrid containing well-dispersed ZnO nanoparticles with an average diameter of 4.5 ± 0.5 nm has been successfully prepared via a one-step sol-gel method. FTIR characterization reveals that GO underwent deoxygenation during the preparation of ZnO nanoparticle. The introduction of RGO in the ZnO-RGO hybrid significantly improved the photocatalytic efficiency of ZnO in the degradation of Rhodamine B under visible light irradiation. The apparent reaction constant of ZnO-RGO is 8 times higher than that of pure ZnO, and the photocatalytic efficiency of ZnO-RGO remains high even after 4 consecutive reactions. Results from the X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area measurements, and electrochemical impedance spectroscopy analysis suggest that the enhancement in the photocatalytic activity of the ZnO-RGO hybrid comes from (1) the enormous surface area provided by the nano-sized ZnO particles, (2) significant dye adsorption from RGO template, and (3) excellent electron reception and conduction of RGO. The attractive properties of ZnO-RGO make it a promising candidate material in addressing the environmental pollution issues we have to face today.