ZnS/CuS nanotubes for visible light-driven photocatalytic hydrogen generation

ZnS/CuS nanotubes are synthesized by using ZnO nanorods as the precursor, followed by sulfuration and subsequent cation exchange reaction. The deposition of CuS on ZnS nanotubes are confirmed by EDS analysis, XPS and UV-Vis diffuse reflectance spectroscopy. HRTEM images clearly display the heterojunctions between ZnS and CuS nanoparticles. ZnS/CuS nanotubes exhibit good photocatalytic activity for H-2 generation without cocatalysts under visible light irradiation (lambda > 420 nm). The H-2 generation rate depends on the CuS content in the ZnS/CuS nanotubes. The highest H-2 generation rate is 85 times higher than that of copper-free ZnS tubes. The highly improved performance for H-2 evolution is supposed to originate from the formation of heterojunctions between ZnS and CuS nanoparticles.