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.

Effect of electron beam irradiation on chemically synthesized nanoflake-like CdS electrodes for photoelectrochemical applications.

In this paper, we chemically synthesized interconnected nanoflake-like CdS thin films for photoelectrochemical solar cell applications and subsequently irradiated them with electron beam irradiation at various doses of irradiation. The as-synthesized and irradiated samples were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical measurements. XRD and XPS results confirmed the formation of CdS with a hexagonal crystal structure. FE-SEM and HR-TEM studies confirmed the photoelectrochemical performance, which was dependent on the surface morphology. The calculated values for efficiency demonstrated an outstanding photoelectrochemical performance with a fill factor of 0.38 and efficiency of 3.06% at 30 kGy. The high photoelectrochemical performance may be due to the interconnected nanoflake-like nanostructure and higher active surface area of the CdS samples. These results show that the electron beam irradiation is capable as an electrode for photoelectrochemical solar cells.

Morphological enhancement to CuO nanostructures by electron beam irradiation for biocompatibility and electrochemical performance.

This paper reports the effect of electron beam irradiation on CuO thin films synthesized by the successive ionic layer adsorption and reaction (SILAR) method on copper foil for supercapacitor and biocompatibility application. Pristine and irradiated samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and electrochemical study. Pristine and irradiated CuO films were pure monoclinic phase, with uniform nanostructures over the whole copper foil. After irradiation, CuO samples had formed innovative nanostructures. Biocompatibility of pristine and irradiated CuO samples suggest that CuO sample is non-toxic and ecofriendly. The specific capacitance of pristine and irradiated CuO strongly depends on surface morphology, and CuO electrodes after irradiation showed superior performance than pristine CuO. The highest specific capacitance of the 20kGy irradiated CuO nanoflowers exceeded 511Fg-1 at 10mVs-1 in 1M KOH electrolyte. Irradiated CuO samples also showed lower ESR, and were superior to other report electrical energy storage materials.

Chemical synthesis of hierarchical NiCo2S4 nanosheets like nanostructure on flexible foil for a high performance supercapacitor.

In this study, hierarchical interconnected nickel cobalt sulfide (NiCo2S4) nanosheets were effectively deposited on a flexible stainless steel foil by the chemical bath deposition method (CBD) for high-performance supercapacitor applications. The resulting NiCo2S4 sample was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical measurements. XRD and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of the ternary NiCo2S4 sample with a pure cubic phase. FE-SEM and HR-TEM revealed that the entire foil surface was fully covered with the interconnected nanosheets like surface morphology. The NiCo2S4 nanosheets demonstrated impressive electrochemical characteristics with a specific capacitance of 1155 F g-1 at 10 mV s-1 and superior cycling stability (95% capacity after 2000 cycles). These electrochemical characteristics could be attributed to the higher active area and higher conductivity of the sample. The results demonstrated that the interconnected NiCo2S4 nanosheets are promising as electrodes for supercapacitor and energy storage applications.

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.

Photoelectrochemical cell studies of Fe(2+) doped ZnSe nanorods using the potentiostatic mode of electrodeposition.

The Fe(2+) doped ZnSe nanorods are synthesized using simple potentiostatic mode of electrodeposition on the ITO substrate. In order to study the doping effect of Fe(2+) in ZnSe, varied the doing percent such as 0.5%, 1%, 1.5%. These films are characterized for structural, compositional, morphological, optical and electrochemical properties using the X-ray diffraction study (XRD), X-ray photoelectron spectroscopy, field emission scanning electron microscopy, UV-vis spectroscopy and electrochemical spectroscopy. Along with these Raman spectroscopy and photoluminescence spectroscopy have been studied for understanding the characteristics vibrations of ZnSe and luminescence of ZnSe nanorods. FE-SEM shows the nanorods like morphology. Photoelectrochemical cell performance studied using the J-V measurement and it shows the maximum efficiency at 1% Fe(2+) doped ZnSe nanorods. The observed maximum efficiency of Fe(2+) doped ZnSe nanorods is 0.32%.