KCl-assisted rapid and low-cost synthesis of antiperovskite (Fe1-xCux)4N anchored on Cu2O nanosheets for highly efficient electrochemical overall water splitting

Developing bifunctional electrocatalysts with abundant reserves and efficient performance is significant for alkaline water electrolysis. Herein, the antiperovskite nitride (FexCu1-x)4N particles anchored on the surface of Cu2O nanosheets have been synthesized by one-step solution combustion synthesis with the assistance of KCl. The (FexCu1-x)4N interacts with Cu2O in the form of p-n junction. Such an assembly effectively promotes the charge transfer under the interval built-in field, which can regulate the electronic densities to greatly increase the reaction kinetics and available active sites. Moreover, the electrocatalysts experience the different structural evolution during HER and OER process. The in-situ reconstructed species possess a proper free energy of adsorbed intermediates for highly efficient bifunctional electrocatalysis via DFT calculation. The optimal (Fe1-xCux)4N-Cu2O heterostructure couples show a superior bifunctional performance for water electrolysis, with a low cell voltage of 1.57 V at 10 mA cm−2 and nearly 100 % Faraday efficiency, surpassing the benchmark precious metal couples.