Visible light-driven photocatalytic H2-generation activity of CuS/ZnS composite particles

CuS/ZnS composite particles with diameter of 200–400 nm were successfully prepared by a simple cation-exchange reaction using ZnS spheres as a precursor. CuS nanoparticles with a few nanometers in diameter were observed on the surface of composite particles. The synthesized CuS/ZnS composite particles showed photocatalytic property effective for H2 evolution from an aqueous Na2S and Na2SO3 solution under visible light irradiation without any cocatalysts. The rate of H2 generation was found to be strongly dependent on the CuS content. The highest rate of H2 evolution reached 695.7 μmol h−1 g−1, which was almost 7 times as high as that of the mechanical mixture of CuS and ZnS. The enhancement in the photocatalytic activity of CuS/ZnS composite particles is supposed to be due to the direct interfacial charge transfer of the CuS/ZnS heterojunction.