Heterostructure CdS/ZnS nanoparticles as a visible light-driven photocatalyst for hydrogen generation from water |
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| Authors: | Xi Wang |
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| Institution: | 1. School of Chemistry and Environment, South China Normal University, Guangzhou, Guangdong, China;2. Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong |
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| Abstract: | (CdS)x/(ZnS)1–x nanoparticles were synthesized as a visible light-driven photocatalyst using the stepped microemulsion technique with a series of the ratio factors (x). The photocatalytic test results showed that (CdS)x/(ZnS)1-x with x = 0.8 had the highest photo-reactivity for H2 production from water under visible light. The composite (CdS)0.8/(ZnS)0.2 catalyst had a heterogeneous structure that exhibited a much greater photocatalytic hydrogen production activity than either pure CdS or the homogeneous Cd0.8Zn0.2S solid solution. ZnS deposition also was shown to largely improve the stability of CdS in the heterostructured CdS/ZnS catalyst. Thermal treatment of the catalyst, i.e., annealing (CdS)0.8/(ZnS)0.2 at 723 K, improved the crystallinity of the catalyst and increased its photocatalytic H2 production rate by more than 36 times. Deposition of Ru on the surface of the catalyst particles by in situ photo-deposition further increased the photo-H2 generation rate by 3 times. The photocatalyst of 0.5%Ru/CdS/ZnS achieved the highest H2 production activity, at a rate of 12650 μmol/g-h and with a light to hydrogen energy conversion efficiency of 6.5%. |
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| Keywords: | CdS-ZnS heterostructure hydrogen generation photocatalyst Ru coating solar energy |
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