Regulating Photocatalytic CO₂ Reduction Kinetics through Modification of Surface Coordination Sphere

Solar-driven reduction of CO₂ to value-added products represents a sustainable strategy for mitigating the greenhouse effect and addressing the related green-energy crisis. Herein, it is demonstrated that modifying the surface coordination sphere can significantly enhance the reaction kinetics and overall efficiency of CO₂ reduction. More specifically, the decoration of isolated Mn atoms over the multi-edged TiO₂ nano-pompons (Mn/TONP) upshifts the d-band center that allows favorable CO₂ adsorption. Ultrafast spectroscopy demonstrates the greatly accelerated charge transfer between photoexcited multi-edged TONP and the newly implanted Mn reactive centers, supplying long-lifetime electrons to reduce absorbed CO₂ molecules. By integrating adsorption and activation functions into the newly decorated Mn sites, the developed photocatalyst demonstrate impressive capacity for CO₂ reduction (80.51 mmol g⁻¹ h⁻¹). The surface modulation strategy at the atomic level not only opens new avenues for regulating the reaction kinetics toward photocatalytic CO₂ reduction, but also paves the way for the rational design of highly efficient and selective photocatalysts for clean energy conversion.