FeCoNi sulphide-derived nanodots as electrocatalysts for efficient oxygen evolution reaction

Although many single- and bi-metal sulfides were reported as bifunctional catalysts for oxygen evolution reaction (OER), The catalytic activity of trimetal sulfides was seldom reported and their catalytic mechanisms need to be further investigated. Herein, trimetal FeCoNi sulphide nanostructures (MSX, M = FeCoNi) are grown on carbon paper as OER catalytic electrodes for alkaline water splitting. The MSX outperforms the state-of-the-art IrO2 in 1M KOH with a reduced overpotential of 250 mV and a superior Tafel Slope of 30 mV dec(-1). It is found that after OER the morphologies of MSX change to nanodots with the smaller size (3-5 nm), therefore, the shorter hydrogen bond on the surfaces of MSX-derived nanodots may enable to significantly reduce kinetic energy barriers for H2O-splitting.