Rational structure design of FeCo-based materials as efficient electrodes for overall water-splitting

Abstract

Rational design of efficient electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential to promote the performance of overall water-splitting. In this work, we demonstrate the high performance electrolyzer by using Fe–Co phosphide grown on Ni foam (FeCoP/NF) as HER electrode and self-supported FeCo2O4@FeCo2S4/NF heterostructure as OER electrode. Thanks to the more active sites and faster charge transfer capability, the FeCoP/NF electrode can deliver low HER overpotentials of 59.6 and 233.6 mV at 10 and 100 mA cm[Formula: see text]. Furthermore, the synergistic effect at interfaces also endows low overpotentials of FeCo2O4@FeCo2S4/NF at specific current densities. As a result, the designed FeCoP/NF——FeCo2O4@FeCo2S4/NF device just needs a voltage of 1.52 V to afford 10 mA cm[Formula: see text], indicating greatly potential in practical application.