TiO2–graphene nanocomposites for photocatalytic hydrogen production from splitting water

TiO2 (P25)–graphene (P25–GR) hybrids were prepared via solvothermal reaction of graphene oxide and P25 using ethanol as solvent. The as-prepared P25–GR nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence emission spectroscopy and ultraviolet-visible (UV–vis) diffuse reflectance spectroscopy. The results indicated that P25–GR nanocomposites possessed enhanced light absorption ability and charge separation efficiency. As photocatalysts, P25–GR hybrids were much better than the bare P25, when they were used in the hydrogen evolution from aqueous methanol solution under Xe-lamp illumination. A significant enhancement in the rate of hydrogen production was achieved through using P25–GR as photocatalysts, comparing to bare P25. The optimum mass ratio of GR to P25 in the hybrids was 0.5 wt%. The higher mass ratio of GR in P25–GR would decrease the photocatalytic activity of P25.