Interface Modulation of rGO/Bi⁰/BiOCl Enables Efficient Electron Utilization for CO₂ Photoreduction

Engineering interfacial electronic structure is critical for enhanced charge utilization and product selectivity in photocatalytic CO₂ reduction toward multi-electron hydrocarbon products. Herein, we report a one-step glycerol-assisted solvothermal strategy to construct ternary catalyst rGO/Bi⁰/BiOCl, in which oxygen vacancies and in-situ formed Bi⁰ nanodomains are intimately integrated with a conductive rGO network. Comprehensive spectroscopic and electrochemical analyses along with in situ EPR and DRIFTS results under CO₂ + H₂O conditions indicate that rGO incorporation not only improves CO₂ adsorption but also alters electron distribution and interfacial charge-transfer dynamics. While defect-rich BiOCl with Bi⁰ enables CO₂ activation, electron accumulation at vacancy sites limits further reduction. In contrast, the rGO/Bi⁰/BiOCl interface facilitates continuous electron extraction and redistribution, preventing charge stagnation and supporting sustained activation of surface intermediates for deeper hydrogenation. This transition from localized electron trapping to dynamic electron utilization enables enhanced selectivity (92%) toward CH₄ and C₂H₄ and exhibits a 12-fold increase in CH₄ photoreduction activity compared to pristine water made BiOCl. This work establishes a design principle for coupling defects with conductive interfaces and identify roles of rGO and Bi⁰ in driving CO₂ reduction to hydrocarbons.