Three-Phase-Heterojunction Cu/Cu₂O-Sb₂O₃ Catalyst Enables Efficient CO₂ Electroreduction to CO and High-Performance...

Zn-CO₂ batteries are excellent candidates for both electrical energy output and CO₂ utilization, whereas the main challenge is to design electrocatalysts for electrocatalytic CO₂ reduction reactions with high selectivity and low cost. Herein, the three-phase heterojunction Cu-based electrocatalyst (Cu/Cu₂O-Sb₂O₃-15) is synthesized and evaluated for highly selective CO₂ reduction to CO, which shows the highest faradaic efficiency of 96.3% at -1.3 V versus reversible hydrogen electrode, exceeding the previously reported best values for Cu-based materials. In situ spectroscopy and theoretical analysis indicate that the Sb incorporation into the three-phase heterojunction Cu/Cu₂O-Sb₂O₃-15 nanomaterial promotes the formation of key ^*COOH intermediates compared with the normal Cu/Cu₂O composites. Furthermore, the rechargeable aqueous Zn-CO₂ battery assembled with Cu/Cu₂O-Sb₂O₃-15 as the cathode harvests a peak power density of 3.01 mW cm^-2 as well as outstanding cycling stability of 417 cycles. This research provides fresh perspectives for designing advanced cathodic electrocatalysts for rechargeable Zn-CO₂ batteries with high-efficient electricity output together with CO₂ utilization.