Effect of different electrolytes and deposition time on the supercapacitor properties of nanoflake-like Co(OH)2 electrodes.

The effect of ultrasonic treatment and deposition time on nanoflake-like Co(OH)2 thin films were prepared using the potentiostatic mode of electrodeposition method on stainless steel substrates by a nitrate reduction reaction. After ultrasonic treatment, we used stainless steel substrates for deposition of the nanoflakes like Co(OH)2 thin films. The effect of deposition times and electrolytes on different physico-chemical properties of Co(OH)2 was investigated in detail, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and electrochemical testing. After ultrasonic treatment Co(OH)2 thin films had devolvement of the uniform and interconnected formation of nanoflakes nanostructures. Supercapacitor performance of the Co(OH)2 electrodes suggest that, specific capacitance are depends on the surface morphology, and Co(OH)2 electrodes after ultrasonic treatment exhibited higher performance than without ultrasonication. The maximum specific capacitance of the 30 min. deposited Co(OH)2 nanoflakes exceeded 276 Fg-1 in 0.5M KOH electrolyte at 5 mVs-1 scan rate.

Chemical synthesis of flower-like hybrid Cu(OH)2/CuO electrode: Application of polyvinyl alcohol and triton X-100 to enhance supercapacitor performance.

In this research article, we report hybrid nanomaterials of copper hydroxide/copper oxide (Cu(OH)2/CuO). A thin films were prepared by using a facile and cost-effective successive ionic layer adsorption and reaction (SILAR) method. As-synthesized and hybrid Cu(OH)2/CuO with two different surfactants polyvinyl alcohol (PVA) and triton-X 100 (TRX-100) was prepared having distinct morphological, structural, and supercapacitor properties. The surface of the thin film samples were examined by scanning electron microscopy (SEM). A nanoflower-like morphology of the Cu(OH)2/CuO nanostructures arranged vertically was evidenced on the stainless steel substrate. The surface was well covered by nanoflake-like morphology and formed a uniform Cu(OH)2/CuO nanostructures after treating with surfactants. X-ray diffraction patterns were used to confirm the hybrid phase of Cu(OH)2/CuO materials. The electrochemical properties of the pristine Cu(OH)2/CuO, PVA:Cu(OH)2/CuO, TRX-100:Cu(OH)2/CuO films were observed by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy technique. The electrochemical examination reveals that the Cu(OH)2/CuO electrode has excellent specific capacitance, 292, 533, and 443Fg-1 with pristine, PVA, and TRX-100, respectively in 1M Na2SO4 electrolyte solution. The cyclic voltammograms (CV) of Cu(OH)2/CuO electrode shows positive role of the PVA and TRX-100 to enhance supercapacitor performance.