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 (SBET) 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 (OV), thereby enhancing the material's surface and internal pores. This process has been demonstrated to result in a significant increase in the SBET 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 OV-rich MIL-125-2H material exhibits the high-performance and highly selective photoreduction in CO2.