The potential of oxygen vacancies (OVs) has been demonstrated in controlling photocatalytic activities by altering the electronic and/or band structures of photocatalysts. The effects of oxygen vacancies on photocatalytic reaction processes are yet unclear. In this work, indium oxyhydroxide (InOOH), well known as a wide band p-block metal compound with OVs, was synthesized through a one-pot solvothermal method to explore the roles of OVs in photocatalytic oxidation and ring opening of toluene. The defect level introduced by OVs enhanced light absorption and charge carrier separation, while promoting the activation of reactants to generate active oxygen species. As such, the modified InOOH was validated to enhance the photocatalytic performance by lowering the reaction energy barrier of the key intermediates during toluene oxidation (relative to the pristine InOOH). More strikingly, the energy barrier for the formation of benzoic acid was reduced with the increasing number of OVs on InOOH (accompanied by the increases in the ring opening reaction rates), in line with the results derived from the in situ DRIFTS investigation and theoretical calculation. Accordingly, it is possible to explain the mechanism regulating the photocatalytic oxidation of toluene on defective InOOH. This work could provide an electronic insight into oxygen vacancy engineering as a new strategy to enhance the photocatalytic selectivity and activity for VOC degradation.

通过改变光催化剂的电子和/或能带结构，已证明氧空位（OVs）的潜力可控制光催化活性。氧空位对光催化反应过程的影响尚不清楚。在这项工作中，通过一锅溶剂热法合成了羟基氧化铟（InOOH），即众所周知的带有OV的宽带p嵌段金属化合物，以研究OV在光催化氧化和甲苯开环中的作用。OVs引入的缺陷水平增强了光吸收和电荷载流子分离，同时促进了反应物的活化以生成活性氧。因此，通过降低甲苯氧化过程中相对于原始InOOH的关键中间体的反应能垒，验证了改性InOOH可以增强光催化性能。更惊人的是，随着InOOH上OV数量的增加（伴随着开环反应速率的增加），苯甲酸形成的能垒降低了。原位DRIFTS调查和理论计算。因此，可以解释调节有缺陷的InOOH上的甲苯的光催化氧化的机理。这项工作可以提供电子空缺工程的电子见解，作为提高光催化VOC降解的选择性和活性的新策略。