Hydrogen production by photocatalytic water-splitting on Pt-doped TiO2-ZnO under visible light

•Pt/TiO2-ZnO displayed a high photocatalytic water splitting activity.•The Pt/TiO2-ZnO has the benefits of preparing easily, environmentally friendly and good re-utilization.•The possible mechanism of photocatalytic splitting water was proposed.

Pt/TiO2-ZnO photocatalytic materials were prepared for the generation of hydrogen gas from water splitting. The photocatalysts were characterized by X-ray diffraction (XRD), UV-visible spectra (UV-Vis), scanning electron microscope (SEM) and transmission electron microscope (TEM). The absorption wavelength of TiO2 was shifted to longer wavelength on Pt/TiO2-ZnO. A 400 W mercury arc lamp with a cutoff filter which filter out all the wavelengths under 400 nm as the visible light source. It reached up to the optimum value of 203 µmolh−1g−1 on TiO2-ZnO (Ti/Zn = 10). A catalyst of 0.5 wt% Pt/TiO2-ZnO (Ti/Zn = 10) was used and a best hydrogen production rate through water splitting was reaching to 2150 µmolh−1g−1. The 0.1 wt% Pt/TiO2-ZnO showed a satisfying long-term stability, and 88% and 77% of initial hydrogen productivity still remained after 7 days and 14 days, respectively.

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