Understanding the synergistic mechanism of single atom Co-modified perovskite oxide for piezo-photocatalytic CO2 reduction

The synergistic effect of novel piezoelectric catalysis and traditional photocatalysis can significantly enhance catalytic performance. Herein, we design novel heterojunction piezo-photocatalysts combining Co-N-C and BiFeO3 (BFO), the yields of CO2 reduction to CO and CH4 with Co-N-C@BFO(1:7) catalyst are up to 1373.41 µmol/g and 169.32 µmol/g, respectively. The displacement current, energy band theory, piezoelectric effect, and in-situ DRIFTS are combined to explain the mechanism. In piezo-photocatalysis, displacement current generates time-varying electrostatic potential, which transfers electrons to the Co-N-C active site and promotes CO2RR. The energy band of the BFO supplier meeting the potential requirements also promotes electron transfer to the Co-N-C active site to participate in CO2RR. The combination of piezoelectric electric fields and visible lights promotes charge separation and improves catalytic activity. This work provides a profound understanding and a new idea for piezo-photocatalytic reduction of CO2.