Lattice Fe/Co dual-doping engineered gallium oxide boosts CC coupling toward highly efficient and selective...

In photocatalytic CO₂ reduction, the slow kinetics of the CC coupling step results in low yield and poor selectivity toward C₂ products (e.g., C₂H₄, C₂H₆). Herein, a Fe/Co lattice co-doped Ga₂O₃ catalyst (Fe₂Co_2.5G) was synthesized via the spatial confinement effect of nanomicelles in a microemulsion system. In contrast to pure Ga₂O₃, which only responds to deep UV light, Fe₂Co_2.5G shows an extended optical absorption edge up to 700 nm. Owing to enhanced photogenerated carrier separation, prolonged photoelectron lifetime, and synergistic electron-rich multi-active sites, Fe₂Co_2.5G exhibits outstanding photocatalytic CO₂ reduction performance, producing C₂H₄ (18.94 μmol g^-1 h^-1) and C₂H₆ (10.68 μmol g^-1 h^-1) with a high C₂ electron selectivity of 85.1%. Density functional theory (DFT) calculations demonstrate that Fe/Co co-doping introduces additional electronic states within the band gap of Ga₂O₃, which effectively modulates the electronic structure of active sites. The d-band center and *CO adsorption energy analyses verify that Fe sites in Fe₂Co_2.5G stabilize the *CO intermediate more favorably, lowering the energy barrier for CC coupling to 0.72 eV. This work provides a feasible strategy to optimize light-harvesting of wide-bandgap semiconductors and construct efficient photocatalysts for CO₂ reduction to C₂ products.