Enhanced CO2 Photoreduction Rate via Constructing Direction d-π Electron Transport Channel of Interfacial Ti-O-Fe

Solar-driven photocatalytic CO 2 reduction provides a sustainable pathway for carbon-neutral fuel production, yet its efficiency is fundamentally limited by the chemical inertness of linear CO 2 and inefficient utilization of photogenerated charge carriers. Effective activation of CO 2 requires electron injection into its antibonding π* orbitals, a process that is poorly matched with conventional oxide photocatalysts. Herein, we construct chemically defined Ti-O-Fe interfacial bonds in TiO 2 /Fe 2 O 3 heterojunctions to establish a directional d→π* electron-transfer channel for CO 2 activation. The optimized TiO 2 /Fe 2 O 3 photocatalyst, synthesized via a one-step hydrothermal method, exhibits broadened visible-light absorption and delivers a CO formation rate of 17.56 μmol·g −1 ·h −1 , over three times higher than that of pristine TiO 2 . Spectroscopic analyses and density functional theory calculations reveal that interfacial electron transfer shifts Fe 3d states toward the Fermi level, enabling strong hybridization with the CO 2 π* orbitals and significantly lowering the free-energy barrier for *COOH formation. This bond-mediated electronic coupling not only suppresses charge recombination but also directs photogenerated electrons toward the CO 2 activation pathway. These results demonstrate that interfacial d-band engineering through chemically specific oxide–oxide bonds provide a powerful strategy to program elementary reaction steps in solar-driven CO 2 reduction beyond conventional band-alignment design.