Facile synthesis of bimetallic Ni–Fe phosphide as robust electrocatalyst for oxygen evolution reaction in alkaline media

Bimetallic Ni–Fe phosphide electrocatalysts were in-situ synthesized through direct phosphorization of metal salts on carbon cloth (CC). The Fe dopant remarkably enhances the OER performance of Ni2P in alkaline medium through the electronic structure modulation of Ni. The (Fe0.5Ni0.5)2P/CC electrode, composed of uniform films coated on carbon fibers, delivers a low overpotential of 260 mV with a small Tafel slope of 45 mV·dec−1 at the current density of 100 mA cm−2, outperforming most reported non-noble electrocatalysts and commercial RuO2 electrocatalyst. The (Fe0.5Ni0.5)2P/CC also displays superior electrochemical stability at high current density. An appropriate Fe dopant level facilitates the in-situ transformation of Ni–Fe phosphides into active NiFeOOH during alkaline OER. This work simplifies the synthesis procedure of metal phosphides. [Display omitted] •Bimetallic Ni–Fe phosphide electrocatalysts are in-situ synthesized on carbon cloth.•Exceptional OER performances are showed by the Ni–Fe phosphide electrocatalysts.•Insight into the mechanisms underlying the excellent OER activities.•Synthetic strategy can be extended into other metal phosphides.