Oxygen Vacancy-Enriched Amorphous Transition Metal Ternary Oxides toward Highly Efficient Oxygen Evolution Reaction

Abstract

Developing highly efficient oxygen evolution reaction (OER) electrocatalysts based on earth-abundant elements is critical to improve the efficiency of water electrolysis, but it remains a challenge. Herein, an amorphous ternary oxides composites FeNiCoO_x/CoO_x with rich oxygen vacancies are developed through a low-cost wet chemical deposition strategy toward this challenge. Benefiting from the synergistic effect of multimetal atom interaction and high exposure of active sites caused by oxygen vacancies and amorphous structure, the as-developed FeNiCoO_x/CoO_x electrocatalyst exhibits an exceptional catalytic performance with a low overpotential of only 221 mV at a current density of 100 mA cm^–2 and negligible performance degradation over 240 h. Furthermore, the FeNiCoO_x/CoO_x-assembled anion exchange membrane water electrolyzer (AEMWE) can achieve a high current density of 1 A cm^–2 at a low voltage of 1.765 V, demonstrating its great potential for practical application.