(569el) Revealing Transition Metal Cocatalyst Effect on Single Crystalline BiVO4 for Photoelectrochemical Water Splitting

Light harvesting based on photocatalytic generation of chemical fuels, or artificial photosynthesis, has long been sought as a renewable solar energy technology. Solar water splitting within a photoelectrochemical is a typical realization of artificial photosynthesis. Bismuth vanadate (BiVO₄, BVO) is an outstanding photoanode material for photoelectrochemical water splitting, and transition metal oxide coating as cocatalyst is a common strategy to improve the performance of photoanode. Here, we review our recent progress on bismuth vanadate multilayer samples coated by different transition metal oxides as cocatalyst, such as cobalt oxide, iron oxide and nickel oxide, which were synthesized by using pulsed laser deposition (PLD) method. BVO samples with different cocatalyst coatings were then used in both photoelectrochemical chlorine generation, and water splitting reactions to have a comprehensive understanding on influence of different transition metal species on BVO’s behavior with simulated solar light. Through changing the thickness of cocatalyst layer and temperature of electrolyte, they were found to have a synergistic effect on photocurrent density and faradic efficiency. Detailed mechanistic research and surface characterizations were performed to understand the inherent correlation between transition metal oxide layer and performance, which will have a heuristic effect towards future photoanode material design for both solar water splitting, chlorine generation and transition metal choosing as cocatalyst.