A novel composite photocatalyst for water splitting hydrogen production

A novel composite photocatalyst, Pt-TiO_2-xN_x-WO₃ was synthesized by the template method and characterized by X-ray diffraction (XRD), ultraviolet-visible light diffusion spectroscopy (UV-vis), and element analysis. XRD spectra indicated that the photocatalyst was in anatase form and the diagnostic peak for WO₃ existed. Combined with the XRD spectra and the results of elemental analysis, the formula of the composite photocatalyst was determined to be Pt-TiO_2-xN_x-WO₃. UV-vis spectra showed the absorption edge was red-shifted to around 750 nm. Under the irradiation of ultraviolet, and with Na₂S/Na₂SO₃ as the sacrificial reagent, the composite photocatalyst showed higher hydrogen production activity than anatase TiO₂, and under irradiation with visible light (λ > 400 nm) it showed higher hydrogen production activity than TiO_2-xN_x while the anatase TiO₂ showed negligible activity. An explanation was put forward for the mechanism of the red-shift of the absorption edge and the hydrogen production activity improvement.