Partially surface exposed CoFe₂O₄ anchored on N-doped carbon endows its high performance for oxygen evolution reaction

The exploration of earth-abundant and high-efficiency electrocatalysts for the oxygen evolution reaction (OER) is of great significant for sustainable energy conversion applications. Although spinel-type binary transition metal oxides represent a class of promising candidates for water oxidation catalysis, their intrinsically inferior electrical conductivity could decrease their electrochemical performances to some extent. Here, we present an metal-organic frame (MOF)-assisted synthesis of partially surface exposed CoFe₂O₄ nanoparticles anchored on nitrogen doped carbon substrate (NC), which can act as the superior catalyst for OER. With enough exposure of active sites and high electron transfer capability and durability, CoFe₂O₄@NC show a low overpotential of 1.517 V at 10 mA · cm⁻² with a Tafel slope of 87 mV · dec⁻¹ in alkaline medium. Moreover, it delivers an outstanding stability with small degradation after 15 h operation. The present work would open a new avenue for the exploration of cost-effective and efficient OER electrocatalysts to substitute noble metals for various renewable energy conversion applications.