Oxygen Vacancy Engineering of Bi24 O31 Cl10 for Boosted Photocatalytic CO2 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 Bi24 O31 Cl10 photocatalyst (Bi24 O31 Cl10 -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 Bi24 O31 Cl10 -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 Bi24 O31 Cl10 . 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.