Nanoporous nonprecious multi-metal alloys as multisite electrocatalysts for efficient overall water splitting

Abstract

Developing robust nonprecious metal-based electrocatalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential for hydrogen production via electrochemical water splitting. Herein, the NiFeCoCuTi alloy is described as a multisite electrocatalyst for highly effective hydrogen and oxygen evolution in alkaline environments. This is achieved by utilizing heterogeneous atoms on the surface that exhibit distinct adsorption behaviors for hydrogen and hydroxyl, thereby accelerating the dissociation of water and mediating the adsorption of hydrogen intermediates required for molecule formation. The monolithic nanoporous multi-metal NiFeCoCuTi alloy electrode displays remarkable alkaline HER and OER electrocatalysis, exhibiting low overpotentials of 48.7 and 264.2 mV, respectively, to deliver a current density of 10 mA cm⁻². Furthermore, it demonstrates exceptional stability for over 100 h in 1 M KOH electrolyte. The exceptional qualities of nanoporous NiFeCoCuTi alloy electrodes make them a highly desirable option for utilization as the cathode and anode material in water electrolysis, which produces hydrogen. They also imply that this is the optimal platform for the development of multisite electrocatalysts.