Kinetic Analysis of WO₃-Modified Cr- and Sb-Codoped TiO₂ for the Photocatalytic O₂ Evolution Reaction

Photocatalysis-electrolysishybrid systems areattractivecandidates for cost-effective green hydrogen production. For thesesystems, it is crucial to improve the O-2 evolution activityof the aqueous solution containing the redox mediators. In this study,a kinetic analysis was conducted, for the first time, to determinethe role of WO3 modified at various temperatures onto Cr-and Sb-codoped TiO2. The kinetic analysis successfullyelucidated the factor that contributed to the higher activity. Basedon this implication, it was revealed that the WO3 speciesincreased the amount of Fe3+ ions at the sliding surfaceowing to the low isoelectric point of WO3, resulting inimproved O-2 evolution activity. Thus, this study proposesa strategy based on kinetic analysis for the design and developmentof photocatalysts with improved activity in the O-2 evolutionreaction.