Facial growth of Co(OH) 2 nanoflakes on stainless steel for supercapacitors: effect of deposition potential

Abstract

In this work, the nanoflakes of Co(OH) 2 have been grown successfully on a stainless steel (SS) substrate at an ambient temperature. The novel architecture, binder free synthesis and considerable capacitance of Co(OH) 2 nanoflakes render them as a potential candidate to be used as an electrode material for supercapacitor application. It is observed that the different cathodic potentials have a dramatic impact on the growth mechanism of Co(OH) 2 nanoflakes. The prepared thin films were subjected for their structural and morphological study using X-ray diffraction, field emission scanning electron microscope, energy dispersive X-ray spectroscopy, etc. The supercapacitive properties of Co(OH) 2 nanoflakes have been studied using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques. The Co(OH) 2 nanoflakes evaluated a maximum specific capacitance of 275 F g −1 for 5 mV s −1 in 1 M KOH.