Performance of amorphous CoS_x/oxygen vacancies ZnO heterojunction photocatalytic hydrogen evolution

CoS_x/OV–ZnO is prepared by two-step hydro-thermal method. The photocatalytic hydrogen evolution amount of ZnO samples is near to zero. The novel composite photocatalyst CoS_x/OV–ZnO have high photocatalytic liveness. It is up to 256 µmol under visible light irradiation for 5 h, which is about increased 30% than CoS_x/ZnO. The hydrogen production number of CoS_x/OV–ZnO do not reduce obviously after 15 h irradiation, it exhibits high photocatalytic stability. The morphologies, surface features and physical characteristics of catalyst are analysed by scanning electron microscope (SEM), X-ray diffraction, X-ray energy spectrum (XPS), Brunner–Emmet–Teller (BET), and fluorescence spectra etc. The SEM results demonstrates amorphous CoS_x is uniformly diffused on the hexagonal wurtzite OV–ZnO. The XPS shows the successful synthesis of ZnO oxygen vacancies. The CoS_x/OV–ZnO has better superficial area and pore volume (BET), which is conducive to the adsorption of EY molecules. The ZnO electron transfer and the charge separation are obviously improved (fluorescence and electrochemical). Accordingly, CoS_x/OV–ZnO might be a latent new photocatalyst.