Quaternary Ni x (CoCuFe) y Se2 nanoparticles towards electrocatalytic alkaline oxygen evolution

Abstract Oxygen evolution reaction (OER) is a key but sluggish reaction during water splitting to hydrogen, and highly-active catalysts are required. Herein, quaternary selenides (Nix(CoCuFe)ySe2) with Ni, Co, Cu and Fe as OER catalysts were developed. The optimal Ni0.86(CoCuFe)0.14Se2 drives 50 mA cm-2 with a low overpotential of ∼265 mV, and has ∼0.956 mA cmECSA-2 of specific activity, which outperforms benchmarked RuO2. The high OER activity of Ni0.86(CoCuFe)0.14Se2 is closely related with the moderate 3d-4p valence band center.