Water splitting by electrodepositing Ni–Co on graphite rod: Low-cost, durable, and binder-free electrocatalyst

Abstract

This research looks at NiCo-based electrocatalytic improvements for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The technique of synthesis, which uses cyclic voltammetry (CV) on the rod of graphite as substrate, provides a unique one-step electrochemical approach. The best conditions for effective catalyst production were discovered by fine-tuning parameters such as cycle numbers, scan speed, and Ni:Co concentration ratios. The major findings indicate that the enhanced Nickel–Cobalt film on a graphite rod demonstrates promising HER performance. Notably, it exhibits moderate overvoltage of −255 mV and −403 mV at current densities of 10 mA cm⁻2 and 100 mA cm⁻2, respectively. Furthermore, the Nickel–Cobalt electrocatalyst produced requires just 380 mV overvoltage to achieve 10 mA cm−2 current density, showing good efficiency of this electrode in OER. This study highlights its high stability, activity, and improved kinetics, attributing these characteristics to new microstructures, a binder-free electrodeposition procedure, and the combined benefits of Nickel and Cobalt. The proposed Nickel–Cobalt electrode, developed through a simple and cost-effective electrochemical deposition, demonstrates high efficiency for both HER and OER, making it a promising candidate for sustainable hydrogen generation.