In-situ evolution of NH4CoPO4·H2O nanoplates on cobalt foil as an efficient and stable electrocatalyst for oxygen evolution reaction

Abstract This paper demonstrates a novel approach to prepare NH4CoPO4·H2O nanoplates on commercial Co foils via a chemical corrosion process. As a 3D self-supported oxygen revolution reaction (OER) electrocatalyst, the as-developed NH4CoPO4·H2O/Co exhibits remarkable electrocatalytic activity and exceptional stability. In specific, it can deliver a catalytic current density of 10 mA cm−2 at an ultralow overpotential of 262 mV. Notably, it can hold its catalytic performance for 100 h at least. The impressive catalytic activity can be mainly attributed to the 3D self-supported configuration that provides abundant exposed active sites and rapid charge transfer and mass transport.