Tailoring <i>p‐p</i> Orbital Hybridization via Oxygen Vacancy in Bismuth Oxybromide Heterojunctions for Efficient Photocatalytic CO <sub>2</sub> Reduction
Jiangchuan Liu, Xiuzheng Deng, Rui Wu, Yani Huang, Jingshan Fan, Jing Li, Huihui Mao, Changhai Liu, Qian Liang
Abstract
Abstract Oxygen vacancies (Ovs) are considered potentially important in photocatalytic CO 2 reduction, yet effectively activating CO 2 and regulating key intermediates toward the target product by Ovs in heterostructure remains challenging. Herein, an Ov‐engineered BiOBr/In 2 O 3 heterojunction (BOvIN) is constructed under polyvinylpyrrolidone (PVP) regulation, which induces the formation of Ov near Bi─O bonds. Experimental and theoretical results indicate that Ov can modify the Bi‐6 p electronic structure to strengthen the interaction with CO 2 , which further regulates the orbital hybridization between Bi‐6 p and C‐2 p ( * COOH), thereby facilitating the rate‐determining step ( * CO 2 → * COOH). Furthermore, the BOvIN S‐scheme heterojunction, featuring an internal built‐in electric field and Ovs‐induced defect states, not only enables CO 2 reduction on BiOBr and H 2 O oxidation on In 2 O 3 with high redox capacity, but also significantly reduces photoexcited charge recombination. Consequently, the BOvIN exhibits a competitive CO production rate of 341.60 µmol g −1 h −1 with ≈100% selectivity in pure water, achieving a record apparent quantum efficiency of 3.55% at 420 nm. This work offers a new perspective on optimizing intermediate adsorption by tuning electronic structure through advanced photocatalysts for efficient and selective photocatalytic CO 2 conversion.