Carbon Nitride Photocatalysts with Integrated Oxidation and Reduction Atomic Active Centers for Improved CO2 Conversion

Single-atom active-site catalysts have attracted significant attention in the field of photocatalytic CO2 conversion. However, designing active sites for CO2 reduction and H2O oxidation simultaneously on a photocatalyst and combining the corresponding half-reaction in a photocatalytic system is still difficult. Here, we synthesized a bimetallic single-atom active-site photocatalyst with two compatible active centers of Mn and Co on carbon nitride (Mn1Co1/CN). Our experimental results and density functional theory calculations showed that the active center of Mn promotes H2O oxidation by accumulating photogenerated holes. In addition, the active center of Co promotes CO2 activation by increasing the bond length and bond angle of CO2 molecules. Benefiting from the synergistic effect of the atomic active centers, the synthesized Mn1Co1/CN exhibited a CO production rate of 47 mu mol g(-1) h(-1), which is significantly higher than that of the corresponding single-metal active-site photocatalyst.

Automated summary

Single-atom active-site catalysts have attracted significant attention in the field of photocatalytic CO2 conversion. However, designing active sites for CO2 reduction and H2O oxidation simultaneously on a photocatalyst and combining the corresponding half-reaction in a photocatalytic system is still difficult. In this study, a bimetallic single-atom active-site photocatalyst with two compatible active centers of Mn and Co was synthesized. The active center of Mn promotes H2O oxidation by accumulating photogenerated holes, while the active center of Co enhances CO2 activation by modifying the bond length and bond angle of CO2 molecules. The synthesized Mn1Co1/CN catalyst exhibited a significantly higher CO production rate compared to the corresponding single-metal active-site photocatalyst due to the synergistic effect of the atomic active centers.