Chemical Coprecipitation-Thermal Synthesis of Nano-Ni-Co Alloy for Efficient Hydrogen and Oxygen Evolution Reactions

Transition metals from the d-group, specifically Fe, Co, and Ni, have demonstrated exceptional electrocatalytic performance as non-noble metal electrocatalysts for water splitting in alkaline electrolytes. In this study, nanostructured Ni-Co alloy electrocatalysts were synthesized using a chemical coprecipitation-thermal method and tested in a 1 M KOH alkaline solution. Five distinct nano-Ni-Co alloy electrodes, each with unique morphologies and structures, were fabricated by varying the composition. The nano-Ni-Co alloy facilitates the adsorption and desorption of H⁺ and OH⁻ ions, thereby enhancing the efficiency of hydrogen and oxygen evolution reactions (HER and OER). Among the tested alloys, the NiCo1 alloy exhibited outstanding electrocatalytic activity in alkaline media, with overpotentials of 267.6 mV for HER and 158.5 mV for OER at 40 mA cm⁻². This work demonstrates a simple and effective synthetic route for integral water decomposition, highlighting the potential of Ni-Co alloys for practical applications in the energy sector.