Regulation of the light absorption and charge kinetics of SmCo DSAs to achieve an efficient photocatalytic CO2RR

Abstract

Inadequate light absorption capacity and low charge separation efficiency are the primary factors constraining the performance of the photocatalytic CO₂ reduction reaction (CO₂RR). Herein, the bis-tris propane (btp) ligand-stabilized SmCo dual-single-atoms (DSAs) are introduced into TpPa-1 covalent organic frameworks (COFs) to form SmCo-btp/TpPa-1. The Sm and Co sites serve as the light absorption center and the catalytic reaction center, respectively. Experimental results demonstrate that the SmCo-btp DSAs enhance the light absorption capacity to generate more photogenerated carriers and promote the charge separation and transfer, thereby improving the efficiency of photocatalytic reactions. Under visible light irradiation, the CO generation rate of SmCo-btp/TpPa-1 is as high as 643.36 µmol g⁻¹ h⁻¹ and the CO selectivity reaches 99.29%, which are 29 and 3.7 times those of Sm-btp/TpPa-1 (21.95 µmol g⁻¹ h⁻¹) and Co-btp/TpPa-1 (173.98 µmol g⁻¹ h⁻¹), respectively. This work presents a potential strategic integration of optical and catalytic active centers to achieve efficient CO₂RR.