Ferrocene-Facilitated Oxygen Vacancies and Fe Doping in BiOCl for Boosted Photocatalytic CO2 Reduction

Abstract In this study, Fe-doped BiOCl photocatalysts with enriched oxygen vacancies (OVs) were synthesized via a one-pot solvothermal method by using ferrocene as an organic iron source. Theoretical calculations and experimental results demonstrate that the ferrocene-assisted preparation of BiOCl induces Fe doping and abundant OVs, achieving the regulation of morphology. Fe doping and OVs reduce the formation energy of BiOCl, stabilize defect structures, induce the generation of defects, promote the separation of carriers, and enhance the adsorption and activation of CO2. Under simulated solar light irradiation, the CO and CH4 production rates over the optimal catalyst (BOC-6) are 2.26 and 5.16 times those on the reference BiOCl, respectively. In situ diffuse reflectance Fourier transform spectroscopy (DRIFTS) reveals the evolution pathway of key intermediates during CO2 reduction. This work highlights the unique advantages of ferrocene as an iron source and provides new insights into the rational design of high-performance BiOCl-based photocatalysts via defect engineering and doping.