Oxygen Vacancy Engineering of Bi 24 O 31 Cl 10 for Boosted Photocatalytic CO 2 Conversion

Unearthing an ideal model to describe the role of defect sites for boosting photocatalytic CO2 reduction is rational and necessary, but it still remains a significant challenge. Herein, oxygen vacancies are introduced on the surface of Bi24O31Cl10 photocatalyst (Bi24O31Cl10-OV) for fine-tuning the photocatalytic efficiency. The formation of oxygen vacancies leads to a new donor level near the conduction band minimum, which enables a faster charge transfer and higher carrier density. Moreover, oxygen vacancies can considerably reduce the energy for the formation of COOH* intermediates during CO2 conversion. As a result, the activity of Bi24O31Cl10-OV for selective photoreduction of CO2 to CO is significantly improved, with a CO generation rate of 0.9 μmol h−1 g−1, which is nearly 4 times higher than that of pristine Bi24O31Cl10. This study reinforces our understanding of defect engineering in Bi-based photocatalysts and underscores the potential importance of implanting oxygen vacancies as an effective strategy for solar energy conversion.