Oxygen Vacancy Engineering of Bi O Cl for Boosted Photocatalytic CO Conversion.

Unearthing an ideal model to describe the role of defect sites for boosting photocatalytic CO reduction is rational and necessary, but it still remains a significant challenge. Herein, oxygen vacancies are introduced on the surface of Bi O Cl photocatalyst (Bi O Cl -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 CO conversion. As a result, the activity of Bi O Cl -OV for selective photoreduction of CO to CO is significantly improved, with a CO generation rate of 0.9 μmol h  g , which is nearly 4 times higher than that of pristine Bi O Cl . 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.