A high-performance oxygen evolution electrocatalyst based on partially amorphous bimetallic cobalt iron boride nanosheet

Abstract

The oxygen evolution reaction (OER) plays a crucial role in various electrochemical energy conversion devices, but it greatly suffers from sluggish kinetic. Therefore, developing economical and high-active electrocatalysts with superior durability and high efficiency for OER is still a huge challenge. Herein, a partially amorphous nanosheet-liked bimetallic cobalt iron boride is directly grown on the nickel foam (CoFeB-5-30 NS/NF) via a facile electroless plating method and adopted as a catalyst for OER. Benefiting from the rational designed nanosheet array which provides large surface areas and more open-pathways to obtain fast electron transportation and gas release, the resulted CoFeB-5-30 NS/NF catalyst exhibits excellent catalytic activity and superior electrochemical stability in alkaline medium. The obtained CoFeB-5-30 NS/NF exhibits an overpotential of 260 mV to reach the current density of 20 mA cm−2. Most importantly, the CoFeB-5-30 NS/NF possesses a small Tafel slope of 38 mV dec−1 and excellent stability with insignificant activity degradation after successive electrolytic measurement (for over 60 h) at 20, 50 and 100 mA cm−2 in 1.0 M KOH, respectively. This work provides a simple and rapid strategy to prepare bimetallic borides and broadens the way for the development of efficient OER catalysts.