Nano-Micro-Structured Nickel-Cobalt Hydroxide/Ni₂P₂O₇ Assembly on Nickel Foam: An Outstanding Electrocatalyst for Alkaline Oxygen Evolution Reaction

The design and development of materials for the efficient electrochemical evolution of oxygen from hydroxyl ions in alkaline media is of prime importance for reducing energy losses in water-alkaline electrolytes. In this Communication, we report non-noble nano-micro-structured Ni₂P₂O₇ microsheets decorated with nickel-cobalt hydroxide (Ni−Co-hydroxide) nanoflakes for the efficient oxygen evolution reaction (OER). Remarkably, the nano-micro-assembled Ni−Co-hydroxide/Ni₂P₂O₇ structured electrode exhibits superior catalytic activity towards the OER with a relatively low overpotential of 197 mV at a current density of 10 mA/cm² in 1.0 M KOH, coupled with excellent long-term stability (12 h). The outstanding OER activity resulted from the nano-micro structure of the prepared electrode with excellent redox activity in an alkaline electrolyte.