Preparation and photoelectrochemical water oxidation properties of ZnO/Ni-B_i composite photoanodes

ZnO nanorods were hydrothermally synthesized on the surface of indium tin oxide glass using precipitate pre-treating method. The ZnO nanorods were uniformly and firmly grown on the indium tin oxide glass and possesed high photoelectrochemical oxygen evolution performance. Then electriocatalysis Nickel-borate were deposited onto the surface of ZnO with electro-assisted photodeposition method. The composite photoanodes were characterized by scanning electron microscopy (SEM), X-ray diffraction(XRD) and the UV-vis diffuse reflection spectroscopy, and the photoelectrochemical water oxidation properties of ZnO/Ni-B_i composite photoanodes were investigated by electrochemical and photoelectrochemical methods. The effect of deposition methods, deposition time and heat treatment progress to the photoelectrochemical oxygen evolution performance of the ZnO/Ni-B_i composited photoanodes were invesigated. The performance of ZnO is improved for as high as 40% after coupling with Ni-B_i. The high oxygen evolution activity of the composite photoanodes can be attributed to seperation and inhibit of hole-electron recombination by Ni-B_i through facilitating the transfer of photon-induced holes from ZnO for water oxidation.