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

Abstract

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.