Photodecomposition of H2S to H2 over Cd x Zn1-x S composite photocatalysts

A series of Cd (x) Zn1-x S (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photophysical properties of Cd (x) Zn1-x S photocatalysts were measured by UV-Vis diffuse reflectance spectrum and surface photovoltage spectroscopy (SPS). The band gap energy gradually reduced with the increasing of x value in CdxZn(1-x) S, and when x = 0.7, the Cd0.7Zn0.3S photocatalyst had the strongest surface photovoltage. Cd (x) Zn1-x S photocatalysts were used in the photodecomposition of H2S to H-2. The evolution rate of H-2 over the Cd0.7Zn0.3S photocatalyst was also the highest among Cd (x) Zn1-x S photocatalysts. And the effect of calcination temperature on the evolution rate of H-2 was investigated and the optimum temperature was 650A degrees C.