Abstract
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•Simple and highly efficient method for deposition of Cobalt based electrode.•Efficient OER performance of Co(OH)2.•Co(OH)2 exhibits low overpotential (290mV) over Co3O4 (340mV) at current density of 10mAcm−2.•Superior performance of Co(OH)2 mainly due to large surface and active sites compare to Co3O4.
The development of an inexpensive, stable, and highly active electrocatalyst for oxygen evolution reaction (OER) is essential for the practical application of water splitting. Herein, we have synthesized an electrodeposited cobalt hydroxide on nickel foam and subsequently annealed in an air atmosphere at 400°C for 2h. In-depth characterization of all the films using X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) techniques, which reveals major changes for their structural, morphological, compositional and electrochemical properties, respectively. The cobalt hydroxide nanosheet film shows high catalytic activity with 290mV overpotential at 10mAcm−2 and 91mVdec−1 Tafel slope and robust stability (24h) for OER in 1M KOH electrolyte compared to cobalt oxide (340mV). The better OER activity of cobalt hydroxide in comparison to cobalt oxide originated from high active sites, enhanced surface, and charge transport capability.