Single-Atom Fe Triggers Superb CO₂ Photoreduction on a Bismuth-Rich Catalyst

Insufficient separation of photogenerated electron–hole and feeble CO₂ activation remain the main obstacles in the access to high-performance CO₂ reduction nowadays. Single-atom active sites engineering could be an efficient method through simultaneously promoting charge separation and CO₂ activation. Herein, a model of Bi₄O₅I₂ with single-atom Fe implanting and accompanying Bi decorating on surface is proposed to boost the performance. The single-atom Fe implantation decreases the value of surface work function, allowing the fast transition of photon-generated electrons from the surface of catalyst to CO₂ molecule. In situ Fourier transform infrared (FT-IR) spectra, CO₂ adsorption measurements, density functional theory (DFT) calculations, and efficient CO₂ activation are realized on as-established single-atom catalyst. An exceptional yield of CO (23.77 μmol g^–1 h^–1) and CH₄ production (4.98 μmol g^–1 h^–1) is acquired over optimized Bi₄O₅I₂–Fe30 with 1.09 wt % of single-atom Fe, superior to Bi₄O₅I₂, and most other reported photocatalysts. The work paves a insight into rational design of photocatalysts toward simultaneously facilitating carrier separation and CO₂ activation from the angle of atom single metal.