Ni-doped ZnS decorated graphene composites with enhanced photocatalytic hydrogen-production performance

This study investigated the abilities of photocatalytic H2 production by Ni-doped ZnS-graphene composite photocatalysts. Undoped or Ni-doped ZnS was loaded on the surface of graphene to prepare a series of composite photocatalysts. Properties of the photocatalysts were characterized by field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible diffuse reflectance spectroscopy (DRS), photoinduced current, and photocatalytic hydrogen evolution test. The as-prepared graphene@Ni-doped ZnS nanocomposites are highly active photocatalysts for hydrogen evolution and the highest photocatalytic activity reaches 8683 μmol h−1 g−1. Effects of introducing graphene, doping, and decorated ZnS on the surface chemistry, crystalline property, optical property, surface morphology, and photocatalytic hydrogen production performance were studied. Ni-doping and decorated ZnS on graphene improved the photocatalytic H2 production activity because of improved dispersing property, increased surface area, increased absorption, and enhanced transfer of photogenerated electrons.