Oriented charge migration induced by Ni−Se bond for enhanced solar fuel generation under infrared light

Narrow-bandgap semiconductors stand out as ideal candidates for photocatalytic reactions, benefiting from their broad-spectrum light-harvesting capability. However, their practical deployment is severely hampered by the intrinsic rapid recombination of photogenerated charge carriers. Herein, we propose a d-band center-regulated single-atom doping strategy to tailor the physicochemical properties of photocatalysts. Specifically, nickel single-atom-doped CuInSe 2 (denoted as NCIS) was synthesized via partial substitution of Cu with Ni ions. Concomitantly, the in-situ formation of Ni–Se bonds establishes a directional pathway for accelerated charge migration. The introduced Ni single atoms exhibit an upshifted d-band center, which not only reinforces CO 2 adsorption and activation but also effectively reduces the reaction barrier for ∗COOH intermediate formation. Notably, the optimized catalyst (2%–NCIS) delivers exceptional CO evolution activity with high selectivity under both full-spectrum illumination and near-infrared (NIR) light irradiation. This work presents a versatile doping paradigm for advancing solar fuel production, particularly in the underutilized NIR region.