Oxygen Vacancy Modification MIL-125(Ti) Promotes CO2 Photoreduction to CO with Near 100% Selectivity

The substantial release of industrial carbon dioxide has been identified as a key factor in the development of various environmental issues. In addressing these concerns, the utilization of photocatalytic technology for carbon reduction has garnered significant attention. The disadvantage of CO₂ photoreduction is the problem of product yield and selectivity. It is known that MIL-125(Ti) with a high specific surface area (S_BET) possesses more active sites using Ti as a node. The calcination of MIL-125(Ti) in a reducing atmosphere has been shown to introduce oxygen vacancies (O_V), thereby enhancing the material's surface and internal pores. This process has been demonstrated to result in a significant increase in the S_BET and an enhancement of the Ti³⁺/Ti⁴⁺ ratio. The increased Ti³⁺ centers have been found to improve the material's reducing properties. The results demonstrate that the O_V-rich MIL-125-2H material exhibits the high-performance and highly selective photoreduction in CO₂.