Engineering the Local Electronic Microenvironment via Interfacial Chelation for Efficient CO ₂ Photoreduction Toward CH ₄

ABSTRACT The photocatalytic conversion of CO ₂ into hydrocarbons using sustainable solar energy offers a promising strategy to address the global energy crisis and achieve carbon neutrality. However, conventional p‐block photocatalysts are often limited by inefficient electron transfer, which restricts the reaction to a two‐electron reduction pathway, primarily yielding CO and impeding the formation of high‐value hydrocarbons like CH ₄ . Herein, we construct a novel BiOCl–BiO(HCOO) heterostructure (denoted as BiOCH), which features interfacial chelating interactions between the [Bi ₂ O ₂ ] ^{2 +} and [HCOO] ⁻ layers within the BiO(HCOO) component, for efficient photocatalytic CO ₂ reduction to CH ₄ . This unique heterostructure broadens the light absorption spectrum and facilitates the separation of photoinduced charges. More importantly, the interfacial Bi─O chelation in BiO(HCOO) modulates the local electronic microenvironment of Bi sites. Mechanistic studies reveal that this modulation enhances the coupling between the C‐2p orbital of the ^* CHO intermediate and the Bi‐p orbital, thereby lowering the Gibbs free energy barrier for the critical ^* CO‐to‐ ^* CHO step and promoting CH ₄ generation. Consequently, the optimized BiOCH catalyst achieves a remarkable CH ₄ production rate of 42.95 µmol·g ^{− 1} ·h ^{− 1} with a high electron selectivity of 95.38%. This work provides a novel design strategy of organic–inorganic hybrid layered structures for steering photocatalytic CO ₂ reduction toward value‐added hydrocarbons.