Electrocatalytic activity of nickel oxide nanoparticles-modified electrodes: Optimization of the loading level and operating pH towards the oxygen evolution reaction

The current study addresses the superior electrocatalytic activity of nickel oxide nanoparticles (nano-NiOx) modified GC, Au and Pt electrodes towards the OER. The electrodeposition of nickel oxide nanoparticles (with an average particle size of 80 nm) are believed to enhance the OER reaction. NiOOH phase, as shown from XRD data, participates in the OER mechanism in such a way to facilitate the charge transfer during various steps in the reaction mechanism through a reversible transformation of NiOOH to NiO2. Optimizing the loading level and the operating pH of the proposed catalyst has been carried out.

► Nickel oxide nanostuctures have been fabricated onto various substrates. ► Enhanced electrocatalytic activity for the oxygen evolution reaction was observed. ► Minute amount of nano-NiOx onto GC decreases the anodic polarization of the OER. ► NiOOH/NiO2 redox is thought to facilitate the charge transfer during the OER.