Effect of Nickel Oxide Synthesis Conditions on its Electrochemical Behavior in Alkaline Media

摘要

Nickel oxide (NiO) was synthesized using three different aqueous-phase precipitation methods, and connections were made between physical and electrochemical properties. Room temperature NaOH-precipitated NiO showed the highest electrocatalytic activity for the methanol oxidation reaction and stability among those synthesized. Microcracking and electrode disintegration was associated with the γ-NiOOH/α-Ni(OH)_2 redox couple in combination with the oxygen evolution reaction. Carbonate electrolytes have potential as a superior reaction medium to hydroxide, evidenced by 3-4 times higher average current densities and 85% lower charge transfer resistances. In addition, its moderate alkalinity limits electrode and membrane deterioration.