Engineering borate modified NiFe layer double hydroxide nanoarrays as “hydroxyl ions hungry” electrocatalysts for enhanced oxygen evolution

Abstract

NiFe layered double hydroxides (NiFe-LDHs) have been regarded as significant electrocatalysts for the oxygen evolution reaction (OER). However, their overpotential must still be further reduced to enable commercial applications. Herein, a promising and highly effective “hydroxyl ions hungry” electrode structure was prepared for the first time via a two-step hydrothermal reaction procedure to enhance the surface adsorption kinetics to obtain an ultralow overpotential. The electrode exhibits OER activity with ultralow overpotentials of 203 mV and 293 mV at the current densities of 10 mA cm⁻² and 100 mA cm⁻², respectively, in 1.0 M KOH. These results reveal an important way to improve the catalytic performance in an alkaline medium.