Honeycomb‐Like Bismuth Oxychloride/Bismuth Titanate S‐Scheme Heterojunction with Enriched Oxygen Vacancies for Efficient Photocatalytic CO ₂ Reduction

In the context of energy shortage and global warming, the transformation of carbon dioxide (CO₂) into value-added chemicals through photocatalytic processes has garnered significant attention. However, constructing highly efficient photocatalytic materials for CO₂ reduction continues to present substantial challenges, especially for the customization of highly efficient heterojunction photocatalysts. Herein, honeycomb-like BiOCl/Bi₂Ti₂O₇ S-scheme heterojunctions with enriched oxygen vacancies are successfully fabricated by an interlayer self-assembly strategy. The experimental results demonstrated that the photocatalytic CO production over BiOCl/Bi₂Ti₂O₇-3 composites reached 48.16 μmol g^-1 h^-1, exhibiting a high selectivity (96.6%) and an excellent stability. The photocatalytic activity exhibited a remarkable improvement, achieving 2.4- and 133.7-fold enhancement compared with that of the pristine BiOCl and Bi₂Ti₂O₇, demonstrating a superior performance of the synthesized composite catalyst. The remarkable enhancement in photocatalytic performance stems from the synergistic effect among the unique interface structure of S-scheme heterojunction, oxygen vacancy engineering, and the porous honeycomb-like morphology. The S-scheme heterojunction, with its unique band structure, can effectively enhance light utilization efficiency, improve the reduction capacity of photogenerated carriers, and thereby accelerate their separation and transfer. This meticulous design presents a unique approach for the customization of S-scheme heterostructures with desirable charge transfer for efficient photoreduction of CO₂ applications.