A Single Cu-Center Containing Enzyme-Mimic Enabling Full Photosynthesis under CO₂ Reduction

Polymeric carbon nitride (CN) is one of the most promising metal-free photocatalysts to alleviate the energy crisis and environmental pollution. Loading cocatalysts is regarded as an effective way to improve the photocatalytic efficiency of CNs. However, commonly used noble metal cocatalysts limit their applications due to their rarity and high cost. Herein, we present the effective synthesis of single-atom copper-modified CN via supramolecular preorganization with subsequent condensation, which provides effective charge transfer pathways by an "infused" delocalized state with variable-valence catalysis at the same time. The C-Cu-N₂ single-atom catalytic site can activate CO₂ molecules and reduces the energy barrier toward photocatalytic CO₂ reduction. Excellent performance for photocatalytic CO₂ reduction was found. This work thereby provides a general protocol of designing a noble-metal-free photocatalyst with infused metal centers toward a wide range of applications.