Synergistically engineered molybdenum-cobalt-nickel sulfide catalysts for enhanced electrochemical activity in overall water splitting applications

Nickel sulfide has emerged as a promising, low-cost catalyst for electrochemical water splitting due to its inherent activity. However, practical application demands higher performance. A key strategy for improvement is creating heterojunctions with other transition metal sulfides, which optimizes charge transfer and increases active sites. In this work, we synthesized MoCoNiS nanosheets via an easy solvothermal method to enhance water splitting efficiency. The composite demonstrated exceptional performance for the Oxygen Evolution Reaction (OER), achieving low overpotentials of 100 mV at 20 mA cm⁻²and 210 mV at 60 mA cm⁻². This efficiency is attributed to the synergistic interactions between the Mo, Co, and Ni components. Similarly, the MoCoNiS material showed excellent activity for the Hydrogen Evolution Reaction (HER), with overpotentials of 211 mV and 290 mV at 20 mA cm⁻²and 60 mA cm⁻², respectively. Evaluating its overall efficiency in a two-electrode configuration, MoCoNiS required only 1.5 V to reach a current density of 10 mA cm⁻². This confirms its high efficiency for complete water splitting and underscores its potential for renewable energy applications. In addition to renewable energy applications, MoCoNiS could provide sustainable power source for assistive and rehabilitation technologies, thereby fostering inclusive advancements within biomedical research.