Photocatalytic hydrogen production with CuS/ZnO from aqueous Na2S + Na2SO3 solution

The photocatalytic hydrogen production in the sacrificial S2−–SO32− anions was investigated with ZnO in the addition of metal sulfides containing Ag2S, CuS, Fe2S3, and NiS. In the absence of metal sulfides, the photocatalytic H2 evolution using ZnO was observed with 255 μmol g−1. The CuS amount and the concentrations of S2− and SO32− ions were optimized. It was found that ternary component semiconductor CuS/ZnS/ZnO was formed during the photocatalytic hydrogen production in the aqueous Na2S + Na2SO3 solution. The photocatalytic hydrogen evolution with CuS/ZnS/ZnO in the 0.4 M Na2S–0.4 M Na2SO3 solution was more than about 8.5 times better compared with those obtained with only ZnO. The CuS clusters on the surface of ZnS/ZnO seem to play an important role on the separation for electron–hole pair and the enhancement of H2 production. Nano-sized ZnS/ZnO photocatalytic hydrogen technology has great potential for low-cost, environmentally friendly solar-hydrogen production to support the future hydrogen economy.