Constructing FeCoSe2/Co0.85Se heterostructure catalysts for efficient oxygen evolution

The slow kinetics and high cost of noble metal catalysts greatly hinder the oxygen evolution reaction (OER) in the application of large-scale oxygen production, as well as water splitting. In order to overcome this burgeoning issue, worldwide research efforts have been carried out to find alternative, and efficient electrocatalysts. Due to its cheap and abundant sources, FeCo-based materials are considered as better candidate electrocatalysts for OER. Herein, a nanocomposite catalyst consisting of FeCoSe2 nanoparticles and Co0.85Se nanosheets was synthesized via a one-pot hydrothermal method. The resultant FeCoSe2/Co0.85Se heterostructure catalysts can further used as a self-supported catalytic electrode to drive the OER, which exhibits the overpotential of 0.33 V at a current density of 10 mA cm−2 and Tafel slope of 50.8 mV dec−1. Raman spectroscopy was employed to explore the intrinsic active species of as-prepared hybrid catalyst during the OER process, and test result shows that metal selenides was acting as the precursor of the real reaction species. This work provides a possibility to develop cheap and effective OER electrocatalysts to replace the costly noble metal catalysts for OER in electrochemical devices. •FCS/CS nanocomposites are synthesized by one-pot method.•5% FCS/CS nanocomposite exhibits the best OER performance.•The real reaction species of CoOOH is formed during the OER process.