Photocatalytic reduction of CO into CH over Ru-doped TiO: Synergy of Ru and oxygen vacancies.

Photocatalytic conversion of CO and HO into CH is an intriguing approach to achieve solar energy utilization and CO conversion, yet remains challenging in conversion efficiency. In this study, we present a synthesis of defected TiO nanocrystal with oxygen vacancies (V) by a facile Ru doping-induced strategy under hydrothermal condition. The synergistic effect of Ru and oxygen vacancies contributed to the enhanced photocatalytic reduction of CO toward CH. Oxygen vacancies and doped Ru not only can synergistically promote the separation of photogenerated carriers, but also promote the CO adsorption, thus enhancing the photocatalytic activities. The optimal Ru-doped TiO (denoted as 1% Ru-TiO) exhibited a remarkable enhanced photocatalytic performance with a CH yield of 31.63 μmol·g·h, which is significantly higher than Ru-TiO and TiO counterparts. This study systematically investigates the multiple roles of Ru in CO reduction and provides new insights for the construction of metal oxide photocatalysts with oxygen vacancies by simple doping of metal ions.