High Performance Photo-Catalyst Based on Nanosized ZnO–TiO₂ Nanoplatelets for Removal of RhB Under Visible Light Irradiation

Nano-sized Zinc oxide–Titanium dioxide (ZnO–TiO₂) nanocomposites containing well dispersed ZnO nanoparticles with an average crystal size of 57 nm has been successfully prepared via a hydrothermal method. FTIR characterization reveals that ZnO–TiO₂ underwent oxygenation during the preparation of ZnO nanoparticle. The introduction of ZnO–TiO₂ in the ZnO–TiO₂ hybrid significantly improved the photocatalytic efficiency of ZnO in the degradation of Rhodamine B under visible light irradiation. The apparent reaction constant of ZnO–TiO₂ is more times higher than that of pure ZnO, and the photocatalytic efficiency of ZnO–TiO₂ remains high even after 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–TiO₂ hybrid comes from surface area provided by the nano-sized ZnO particles, significant dye adsorption from TiO₂ template, and excellent electron reception and conduction of TiO₂.