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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 BiFeO 3 (BFO), the yields of CO 2 reduction to CO and CH 4 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 CO 2 RR. 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 CO 2 RR. 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 CO 2. [Display omitted] • The Co-N-C@BFO piezoelectric catalyst with high active site was successfully designed and prepared. • Displacement current, energy band tilt and piezoelectric effect promote the charge separation efficiency greatly. • The synergistic effect of mechanical vibration and visible light driving enables the catalyst to have good reduction performance for CO 2 RR. • The reduction pathways and intermediate species are investigated by in-situ DRIFTS. [ABSTRACT FROM AUTHOR]

Inclusive quantum dots hollow CN@CIZS heterojunction has been successfully prepared and for accelerating photocatalytic CO 2 reduction. It exhibits excellent photocatalytic performance. [Display omitted] • The heterojunction between hollow g-C 3 N 4 and CuInZnS QDs is successful designed, and exhibits outstanding CO 2 RR performance. • The hollow architecture affords a larger specific surface area and enhances light absorption for photocatalysis. • CuInZnS QDs can increase the adsorption and activation capacity of CO 2 on hollow g-C 3 N 4. • Optimization of the photocatalytic performance was strongly demonstrated by in-situ DRIFTS and other photochemical tests. Photocatalytic conversion of carbon dioxide (CO 2) to fuel or useful chemicals is of great significance for energy and environmental issues. Herein, we successfully prepare a hollow g-C 3 N 4 @Cu-In-Zn-S quantum dots (CN@CIZS QDs) photocatalytic heterojunction employing the method of electrostatic self-assembly. The hollow structure, multiple exciton effect of quantum dots and the discrepancy of band structure generate excellent photocatalytic performance. The yield of CO 2 photocatalytic reduction to CO and CH 4 respectively is 23.04 μmol g−1 and 13.92 μmol g−1 after simulated visible light irradiation for 6 h for hollow CN@CIZS QDs 20 wt% sample. Moreover, the results of in-situ characterization and other photochemical tests strongly demonstrate the significant optimization of the photocatalytic performance. The research offers a feasible green thought for the resource utilization of CO 2. [ABSTRACT FROM AUTHOR]

The selective reduction of carbon dioxide (CO 2) as the primary component of greenhouse gas, remains a significant challenge in photocatalysis. Here, we present a novel strategy of preparing highly selective and stable heterostructure photocatalysts, which simultaneously contain oxygen and nitrogen vacancies. Synergistic catalysis effect originated from Nb 2 O 5 with oxygen vacancies and nitrogen-rich vacancies of metal-free catalytic (g-C 3 N 4) substrate leads to excellent photocatalytic reduction performances. The as-prepared photocatalysts exhibit outstanding capacity of selective reduction of CO 2 with yields of CH 4 16.07 μmol g−1 and CO 0.89 μmol g−1 after 5 cycles. Furthermore, the CO 2 reduction mechanism is confirmed through density functional theory (DFT) calculation and in-situ technology in detailing. This indicates that the heterojunction surface has a lower free energy barrier for CO 2 reduction compared with the pristine sample surface. This new strategy may exploit a vital application of dual-vacancy heterostructure in environmental catalysis. The designed dual-vacancy Nb 2 O 5 @g-C 3 N 4 heterojunction forms a highly stable V 1 -C-O-V 2 configuration. The configuration boosts photocatalytic CO 2 reduction with highly selective conversion to CH 4. [Display omitted] • Rich oxygen and nitrogen vacant g-C 3 N 4 -Nb 2 O 5 heterojunction is successful designed. • Dual-vacancy structure increases the adsorption and activation capacity of CO 2 on V O,N -NBCN. • The V O,N -NBCN exhibits enhanced photocatalytic CO 2 RR with highly selective conversion to CH 4. • The active reduction pathways and intermediate species are investigated by DFT calculation and in-situ DRIFTS. [ABSTRACT FROM AUTHOR]