Nanocomposite catalyst of graphitic carbon nitride and Cu/Fe mixed metal oxide for electrochemical CO2 reduction to CO

Abstract

To address the challenges of excessive emission of CO2, development of highly efficient electrocatalysts based on earth-abundant metals and non-metals for CO2 reduction is of great importance. Herein, we report a novel g-C3N4/Cu2O-FeO heterogeneous nanocomposite catalyst for electrochemical CO2 reduction to CO, with a maximum Faradaic efficiency of 84.4 % at a low onset overpotential of -0.24 V vs. normal hydrogen electrode (NHE). Moreover, the turnover frequency for CO2 conversion to CO reached 10300 h−1 with a high selectivity of 96.3 % at -1.60 V vs. Ag/AgCl, corresponding to a thermodynamic overpotential of -0.865 V vs. NHE. The excellent CO2 reduction to CO can be attributed to the intimate interfacial interaction between the g-C3N4 and metal oxides (Cu2O-FeO) and the higher electrochemically active surface area. Therefore, this work demonstrates the use of a g-C3N4/mixed metal oxide heterostructure as a novel and efficient nanocomposite for electrocatalytic CO2 reduction in neutral aqueous medium.