The Role of Dual Vacancies in TiO2 for Enhanced Photocatalytic Hydrogen Generation and Pollutants Removal

The mechanism of TiO2 with Ti vacancy and O vacancy in photocatalytic hydrogen production is unknown. Herein, TiO2 with three types of vacancies was constructed. It was found that DV-Ti-3O containing both O vacancies and Ti vacancies had the highest photocatalytic hydrogen production of 12.42 mmol.g(-1).h(-1) twice that of SV-Ti, where the O vacancy acted as an emitter providing a directional path for the migration of photogenerated electrons and provided the adsorption sites for water molecules, while the introduction of Ti vacancies took the role as electron traps to collect more electrons for hydrogen proton reduction. DV-Ti-3O achieved ultra-fast migration of electronics from O vacancies to Ti vacancies and created ideas for defective engineering of non-precious metal catalysts for photocatalytic hydrogen production and organic pollutants removal.

Automated summary

The mechanism of Ti vacancies and O vacancies in TiO2 for photocatalytic hydrogen production was investigated. It was found that TiO2 with both O vacancies and Ti vacancies showed the highest photocatalytic hydrogen production. O vacancies acted as emitters for electron migration and provided adsorption sites for water molecules, while Ti vacancies served as electron traps for hydrogen proton reduction. This study provides insights for the development of efficient non-precious metal catalysts for photocatalytic hydrogen production.