An earth-abundant, amorphous cobalt-iron-borate (Co-Fe-Bi) prepared on Ni foam as highly efficient and durable electrocatalysts for oxygen evolution

Abstract

The rational designing of Earth-abundant, low-cost and efficient oxygen evolution reaction electrocatalysts is prerequisite to develop the alternative sustainable energy sources. In this work, we demonstrate the development of a highly efficient and durable electrocatalyst based on an amorphous Co-Fe-Bi directly grown on three-dimensional nickel foam via a facile solution approach. Co-Fe-Bi electrocatalysts on nickel foam exhibits an overpotential of ~307 mV to achieve the geometrical current density of 10 mA cm−2, a low Tafel slope of ~68.6 mV dec−1 and outstanding durability for 40 h at a mass loading of 1.2 mg cm−2, which is superior to those of borate-based electrocatalysts reported in the literature. This remarkable preliminary electrocatalytic performance in Co-Fe-Bi originates from the synergistic influence of unique binder-free ultra-thin nanosheets on the three dimensional porous structure, amorphous nature of multimetal-metalloid complex with highly abundant catalytically active sites and high conductivity of nickel foam. This work holds a great promise in the design and development of highly efficient and durable electrocatalysts at a large-scale based on an amorphous bimetallic borate nanosheets using a facile one-step solution process.