A high-performance bimetallic cobalt iron oxide catalyst for the oxygen evolution reaction

Abstract

Due to the sluggish kinetics, the oxygen evolution reaction (OER) restricts the feasible application of water splitting. Herein, we have reported bimetallic cobalt iron oxide (CoFe₂O₄) with a nanosphere structure as a highly efficient electrocatalyst for OER. Benefiting from the unique mesoporous structure, the as-synthesized CoFe₂O₄ nanospheres presented superior electrochemical properties to those of the corresponding monometallic Fe₃O₄, Co₃O₄, and even commercial RuO₂. As a result, the overpotential of the CoFe₂O₄ electrocatalyst was only 275 mV up to 10 mA cm⁻² and a Tafel slope of 58.6 mV dec⁻¹ was obtained. Besides, there was negligible variation between the LSV curves obtained before and after conducting 4000 cycles, testifying the outstanding long-term stability.