Orderly Drawing Photo-Thermal Synergistic Electron Flow for Efficient CO₂ Reduction under Natural Sunlight

Photocatalysis is a green promising approach for CO₂ reduction. Metal sulfides are widely studied in this field due to the high-efficiency, however, most of them are prone to photo-corrosion. Herein, a stable and efficient Z-scheme heterojunction catalyst is reported, Fe_xIn_yS_z/TiO₂ owing an orderly drawing photo-thermal synergistic electron flow for CO₂ reduction in a field experiment. The tests under natural sunlight conditions demonstrated that Fe_xIn_yS_z/TiO₂ has a stability of 4 natural days. The maximum photothermal energy conversion efficiency is 1.16%, which is the highest record under concentrated natural sunlight for CO₂ reduction with pure water. The in situ rapid-scan XANES and XPS show the raising temperature and photo-irradiation synergistically stretch electrons from O to Fe, revealing the mechanism of thermal modulation to optimize the active sites for efficient and stable photocatalytic CO₂ reduction. This work pioneers the stable and efficient reduction of CO₂ under outdoor sunlight conditions, providing a theoretical foundation for the outdoor application of this technology.