Department Of Physics

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    Fabrication of activated carbon coated MSe2 (M=Mo, Co, and Ni) nanocomposite electrode for high-performance aqueous asymmetric supercapacitor
    (Elsevier B.V., 2023-03-09T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
    Transition metal diselenides are trendy electrode materials for supercapacitors. The main reason behind it is their high specific capacitance. But, they suffer from poor electronic conductivity and agglomeration issues which hinder their practical use. Herein, we present the preparation of nanocomposites including transition metal diselenide MSe2 (M=Mo, Co, and Ni) with activated carbon using the facial hydrothermal route. Inspiring from the high electrochemical results of a hybrid nanocomposites symmetric cell, an aqueous asymmetric ultracapacitor cell (AUC) comprised of different shaped carbon-coated MSe2 (positive electrode) as well as activated carbon (AC) (negative electrode) has been fabricated. The NAC//6KOH//AC asymmetric cell displays the best outcomes among all fabricated devices. The specific capacitance observed is about 3740 F g?1 at 10 mV s?1. It delivers a high energy density of 69 Wh kg?1 along with a power density of 687 W kg?1 at 1 A g?1. The electrochemical results motivate us to explore the practical usability of the prepared NAC//6KOH//AC device via illuminating 26 red LED panels which glow for 26 min. The findings in this report indicate that MSe2-based nanocomposite has the scope and is a potential material in the energy storage field. � 2023 Elsevier B.V.
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    Microwave scattering behaviour of carbon black/ molybdenum di sulphide /cobalt composite for electromagnetic interference shielding application
    (Elsevier Ltd, 2022-01-28T00:00:00) Yadav, Akshita; Tripathi, Krishna C.; Baskey, Himangshu B.; Alegaonkar, Prashant S.
    Erasing signature of an object from an enemy's radar is, tactically, disruptive move achieved by the effective electromagnetic interference (EMI) shield. We report on the microwave scattering (2�18 GHz) behaviour of the nano-composite for architecting efficient shield composed of carbon black (CB), molybdenum di sulphide (MoS2) and cobalt (Co). Nano-composite, prepared by a facile, solid state synthesis route, are characterized using infrared, x-ray diffractometry, UV�visible, energy dispersive x-ray spectroscopic techniques including scanning electron microscopy. In infrared and Rayleigh analysis, formation of -C-Mo-C, O[dbnd]S[dbnd]O, Mo�O, and Co�O phases generated asymmetric polarization at low % CB content that gets transformed into a symmetric mode due to formation of Co�O and Co�S�C radicals at high CB % to cause maximum power losses. Possible polarization mechanism is discussed. In constitutive analysis, two-fold increase in the dielectric function, the dual behaviour (Debye and Jonscher) of the ac conductivity, and the synergistic magneto-dielectric coupling factor influenced the scattering performance of the composite. Broadly, at 18% composition, the shielding effectiveness is recorded to be > 97@14 GHz with 7.7 GHz of the bandwidth and the thickness ?2.5 mm. The Dallenbach return loss is almost 75% revealing a high-performance shield design @18% CB/MoS2/Co nano-composite. � 2022 Elsevier B.V.