DOI: https://doi.org/10.29363/nanoge.interect.2022.021
Publication date: 11th October 2022
Artificial photosynthesis, inspired by natural photosynthesis, is considered a promising technology to store solar energy into chemical bonds, such as NH3, H2 or carbon-based fuels via (photo)electrochemical water splitting, ammonia reduction or CO2 reduction. This process is usually limited by the oxidation reaction taking place at the photoanode, in particular n metal-oxide photoanodes. The photoelectrochemical performance of these photoanodes vary depending on their synthetic route and post-synthesis treatment that can lead to crystal defects such as oxygen vacancies. However, the chemical nature of such oxygen vacancies and their role in photoelectrochemical oxidation of water or organic substrates to produce high added-value chemicals is still in debate.
In this talk, I will present a spectroscopic, microscopic and electrochemical analysis of the chemical nature of light-induced oxygen vacancies in one of the most studied photoanodes such as BiVO4. Oxygen vacancies in these BiVO4 photoanodes were produced by light exposure treatments and are associated with the migration of Bi towards the surface forming nanoparticles.[1] Additionally, I will show the role of oxygen vacancies in the photoelectrochemical behaviour of BiVO4, WO3[2] and a-Fe2O3[3] photoanodes and their role in the water oxidation mechanism as example.