Partially amorphous iron-copper-nickel sulfides for robust bifunctional electrocatalysis

Bifunctional electrocatalysts are in demand to pursue dual functions in applications like energy conversion and pollution treatment. In this study, we synthesize the iron-copper-nickel sulfide (FeCuNiS) catalysts with partial amorphous character via the hydrothermal method. The iron rich composition with optimal copper and nickel ratios exhibits robust performances on hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline conditions. The partial amorphous feature offers more active sites for reaction due to the partial disordered structure. The partially amorphous FeCuNiS exhibits lower overpotential for HER and OER at 50 mAcm^- 2. Moreover, all compositions were found to be electrocatalytically stable. The optimum design and synthesis strategy of the partially amorphous bifunctional electrocatalysts provided in this work will open pathways to advanced electrocatalysts for energy conversion applications.