Fe/Co bimetallic borides with modified electronic structure for Efficient oxygen evolution reaction

Abstract

Bimetallic compounds usually exhibit superior properties to monometallic compounds, owing to the synergistic effect between two components. Herein, a bimetallic boride (FeB/CoB) has been successfully fabricated by the in-situ solid state reaction. When used as electrocatalyst toward the oxygen evolution reaction (OER), the activated bimetallic boride delivers an overpotential as low as 262 mV at 10 mA cm⁻² and exhibits a satisfactory stability over 60 h, surpassing the commercial RuO₂ catalyst. Theoretical calculations indicate that the high intrinsic OER activity of FeB/CoB originates from the modified electronic structure that effectively facilitates electron transfer. Therefore, this work indicates that the bimetallic borides with low cost and high performance have the potential application as anodic electrocatalysts in electrochemical water splitting.