A high-performance oxygen evolution electrode of nanoporous Ni-based solid solution by simulating natural meteorites

Abstract

Transforming the intermittent solar and wind energies into green hydrogen energy by water electrolysis is deemed to be a promising approach to substitute traditional fossil energies. However, the scarcity of precious IrO2/RuO2-based metal oxides for oxygen evolution reaction hinders the large-scale utilization. Here, based on the nanoscale Kirkendall effect, we fabricate nanoporous γ-Ni based solid solution with the simulated FeCoNi surface compositions of Gibeon meteorites by a facile microwave sintering method. A metal (oxy)hydroxide layer with a thickness of approximately 9 nm was formed on the surface of as-prepared electrode after aging, achieving an overpotential of only 254 mV at 10 mA cm−2 and a low Tafel slope of 37.0 mV dec−1. The electrode exhibits outstanding long-term stability in a wide range of current densities without compromising the electrocatalytic activity, which is attributed to the 3D-interconnected nanoporous structure, synergistic effect of different species, high conductivity and excellent wettability. The fabrication of nanoporous non-precious solid solution architectures which mimic naturally-formed materials provides a feasible strategy for the design of high-performance electrocatalysts towards clean energy applications.