Synergetic catalysis of CuO and graphene additives on TiO2 for photocatalytic water splitting

A highly efficient and visible-light-responsive CuO/TiO2-GR photocatalyst had been synthesized by a two-step process. The as-prepared CuO/TiO2-GR composites were characterized by X-ray diffraction, N2-physisorption, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectra, UV–vis diffuse reflectance spectra and Photoluminescence spectra. The results indicated that a chemical bond formed between GR and TiO2 in CuO/TiO2-GR composites. CuO/TiO2-GR composites had a higher photocatalytic activity for hydrogen production due to a synergistic effect between CuO and GR. The synergistic effect could efficiently suppress charge recombination, improve interfacial charge transfer, enhance visible-light adsorption and provide plentiful phtotocatalytic reaction active sites. The maximum hydrogen evolution rate of CuO/TiO2-GR-0.5 was 2905.60 μmol/(h·g), which was 20.20 times larger than pure P25.