Synergistic interactions between g-C3N4 and Cu–Zn-MOFs via electrostatic assembly for enhanced electrocatalytic CO2 reduction†

Abstract

Electrocatalytic carbon dioxide reduction (eCO₂R) represents a sustainable technique for converting CO₂ into valuable chemicals and fuels. Metal–organic frameworks (MOFs) are recognized as promising candidates in eCO₂R due to their favorable adsorption of CO₂. However, the insufficiency of adequate active sites restricts their in-depth investigation. Herein, inspired by the interfacial electronic effects, the layered g-C₃N₄ with unpaired electron characteristics is integrated into Cu–Zn-MOFs with nucleophilic imidazolate ligands via electrostatic assembly. The resultant g-C₃N₄@Cu–Zn-MOFs-1 : 1 exhibits excellent CO₂ reduction performance for CO in a wide potential range, where the peak faradaic efficiency reaches 85% at −1.3 V. g-C₃N₄ with a graphitic carbon backbone significantly stabilizes the Cu–Zn-MOF structure and enhances the exposure of active sites. The excellent performance stems from the significant activation of active sites by the efficient electron transfer induced by π–π stacking interactions between g-C₃N₄ and Cu–Zn-MOFs-1 : 1. This work proposes an innovative approach to stabilizing MOFs and activating the active sites in MOFs through interfacial electron engineering for CO₂ reduction.