Herein, this report uses Co3O4 nanoneedles to decorate Mo-Co3O4 nanosheets over Ni foam, which were fabricated by the hydrothermal route, in order to create a supercapacitor material which is compared with its counterparts. The surface morphology of the developed material was investigated through scanning electron microscopy and the structural properties were evaluated using XRD. The charging storage activities of the electrode materials were evaluated mainly by cyclic voltammetry and galvanostatic charge-discharge investigations. In comparison to binary metal oxides, the specific capacities for the composite Co3O4@Mo-Co3O4 nanosheets and Co3O4 nano-needles were calculated to be 814, and 615 C g−1 at a current density of 1 A g−1, respectively. The electrode of the composite Co3O4@Mo-Co3O4 nanosheets displayed superior stability during 4000 cycles, with a capacity of around 90%. The asymmetric Co3O4@Mo-Co3O4//AC device achieved a maximum specific energy of 51.35 Wh Kg−1 and power density of 790 W kg−1. The Co3O4@Mo-Co3O4//AC device capacity decreased by only 12.1% after 4000 long GCD cycles, which is considerably higher than that of similar electrodes. All these results reveal that the Co3O4@Mo-Co3O4 nanocomposite is a very promising electrode material and a stabled supercapacitor.
1 November 2018 in Materials Science in Semiconductor Processing
Replacing precious metals with low-cost metals is the best solution for large scale production. Copper is known for its excellent conductivity and thermal management applications. When it comes to hydrogen evolution reaction, it is highly unstable, especially in KOH solution. In this paper, we approached a simple method to reduce corrosion and improve the performance by depositing nickel-molybdenum oxide and nickel on copper substrates and the achieved tafel slopes of 115 mV/dec and 117 mV/dec at 10 mA/cm2. While at first, molybdenum oxide coated samples showed better performance after 100 cycles of stability tests, the onset potential rapidly changed. Cu-Ni, which was deposited using the electron gun evaporation (e-gun), has shown better performance with 0.28 V at 10 mA/cm2 and led to stability after 100 cycles. Our results show that when copper is alloyed with nickel, it acts as a promising hydrogen evolution reaction (HER) catalyst.
In this study, the effect of deposition time on physical properties of tin monosulphide films capped by polyvinyl alcohol was investigated. Chemical bath deposition technique was used to...
26 October 2018 in Material Science Research India
Spray deposited Mo-doped zinc oxide (MZO) films were grown on glass substrates at different substrate temperatures (Ts)that varied in the range of 300°C-450 °C at aconstant Mo-doping concentration of 2 at. %.XRD spectra revealed better crystallinity of films prepared atTs400 °C. FTIR spectra showed the vibrational modes related toZn–O bonding.Photoluminescence spectra of MZO films showed a peakrelated toviolet emissionsbetween 400 nm and 420 nm. Electrical analysis showed n type semiconducting nature of the films and the films grown at Ts= 400 °C hadlow resistivity and high mobility.Adetailed analysis on theeffect of substrate temperatureon photoluminescence and electrical propertiesof MZO films wasdiscussed and reported.