Achieving Highly Selective Photocatalytic CO 2 Reduction to CO via an S‐Scheme CuPc/Ni Co‐Modified g‐C 3 N 4 Heterojunction

Photocatalytic CO 2 reduction driven by solar energy is a promising route for sustainable carbon utilization, yet achieving high CO selectivity with efficient charge separation remains challenging. Herein, a CuPc–Ni co‐modified g‐C 3 N 4 (CN) photocatalyst was constructed via an impregnation–photodeposition strategy to enable selective CO 2 ‐to‐CO conversion without sacrificial agents. CuPc enhances visible‐light absorption, while Ni acts as an electron sink to suppress charge recombination. Photoelectrochemical measurements and band structure analyses reveal the formation of an S‐scheme heterojunction that promotes directional charge migration. The optimized 5%CuPc–5%Ni/CN catalyst delivers a CO production rate of 9.71 μmol·g −1 ·h −1 with a high CO selectivity of 96%, along with good cycling stability. In situ diffuse reflectance infrared Fourier transform spectroscopy identifies * HCOO as a key intermediate, indicating a formate‐mediated reaction pathway. This work provides an effective strategy for constructing S‐scheme CN‐based photocatalysts toward highly selective CO 2 reduction.