Cobalt-based co-ordination complex-derived nanostructure for efficient oxygen evolution reaction in acidic and alkaline medium

Abstract

Electrochemical water splitting is one of the most important method for energy conversion and storage. For this, the design and development of a low-cost robust electrocatalyst are highly desirable. In this study, Cobalt-based electrocatalyst for Oxygen Evolution Reaction was synthesized by thermal treatment of Cobalt-dehydroacetic acid (Co-DHA). The as-synthesized Co nanostructures and Co-DHA crystals were characterized with powder X-ray diffraction, X-ray photoelectron spectroscopy thermo-gravimetric analysis, and field emission scanning electron microscopy. The electrochemical O2 evolution study shows the overpotential (at 10 mV/cm−2) correspond to 294 mV vs reference hydrogen electrode (RHE) for K-300 (Co3O4@300), whereas K-500 (Co3O4@500) shows 170 mV vs RHE values in 1 M KOH solution, respectively. Similar trends have been observed for electrochemical O2 evolution studies in 0.5 M H2SO4, where K-300 and K-500 shows the overpotential (at 10mV/cm−2) of 234 mV vs RHE, and 199 mV vs RHE, respectively. The outcomes show better catalytic efficiency of K-500 as compared to K-300.

Keywords

• Cobalt nanostructures
• Dehydroacetic acid
• Cobalt oxide
• O2 evolution
• Electrocatalyst