| Abstract:It is still a challenge for WO3photoanode to meet the requirements of practical application due to the high recombination of photo-generated electrons and holes, the low utilization of solar light. Additionally, the rate of oxygen evolution reaction is awkward for the reaction kinetics and this will indirectly affected the hydrogen evolution reaction. In this paper, we aim to study the impact of heterostructure properties on WO3photoanode and fabricate the NiWO4/WO3, CuWO4/WO3heterojunction photoanode with deposition-annealing method.NiWO4/WO3, CuWO4/WO3heterojunction photoanode were fabricated for the first time to enhance the photoelectrochemical (PEC) performance under visible light irradiation. Such two photoanodes was prepared using a simple deposition-annealing method of NiWO4, CuWO4onto the surface of porous WO3films and the morphologies has never been changed after NiWO4, CuWO4coating. Synthesis details are discussed, with film morphologies and structures characterized by X-ray diffraction, field emission scanning electron microscope, transmission electron microscope and X-ray photoelectron spectroscopy. It was found that the NiWO4/WO3and CuWO4/WO3films synthesized with25mmol/L Ni(NO3)2and20mmol/L Cu(NO3)2in ethanol exhibited the best PEC performance, which achieved70%and50%increase compared with the pure WO3film under similar conditions. Through the Mott-Schottky and the electrochemical impedance spectroscopy (EIS) analyses, a conclusion can be drawn that the NiWO4/WO3and CuWO4/WO3films have advantages of effective separation and restraining the recombination of the photo-generated electron-hole pairs and better electron transport properties, which resulted in enhancing PEC performance. |
PDF Full Text Request