Department Of Physics
Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/57
Browse
2 results
Search Results
Item Aging impact of Se powder on the electrochemical properties of Molybdenum selenide: Supercapacitor application(Elsevier Ltd, 2022-02-10T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.In the present report, we have studied the impact of aging on selenium (Se) powder in hydrazine hydrate (act as reducing agent) during synthesis of pure molybdenum selenide (MoSe2) material. The MoSe2 as electrode material is prepared via single-step hydrothermal technique with aging Se powder in reducing agent for zero, one, and three days. The structural, microstructural, and chemical nature analysis of the samples was done via XRD, FESEM, and FTIR tools whereas the electrochemical study was performed via CV, GCD, and EIS techniques. The optimized material coded as M 39 (three days aged sample with pH 9) shows a high specific capacitance (Cs) of 368 F g?1 at the current density of value 0.5 A g?1 along with an energy density of 51 Wh kg?1 and power density of 250 W kg?1. Based on the electrode's electrochemical outcomes, it may be indicated that the electrochemical performance of MoSe2 material upsurges as the aging of Se increases from zero to three days. From the obtained results it is could be predicted that the M 39 material may stand appropriate for commercial supercapacitors. � 2022Item Structural and electrochemical performance of carbon coated molybdenum selenide nanocomposite for supercapacitor applications(Elsevier Ltd, 2021-12-14T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.Among the recent trends of supercapacitor electrode materials, transition metal dichalcogenides based composite materials have become popular due to their ability to have high electronic conductivity, variable oxidation states, large surface area, a porous structure. Herein we report, a composite material based on MoSe2 as electrode prepared using a standard single-step hydrothermal strategy. The structural and morphological study of the prepared material confirms the formation of the composite. The specific surface area has been estimated using BET technique and found to 522 m2 g ? 1 with average pore diameter as 4.6 nm. In all prepared composite electrodes, M@AC 1:5 electrode exhibits the highest specific capacity of 514 F g ? 1 at a scan rate of 10 mV s ? 1 for potential window 1 V in KOH electrolyte solution. The electrochemical impedance spectroscopy (EIS) study of the M@AC 1:5 electrode shows good agreement with cyclic voltammetry and galvanostatic charge-discharge storage mechanism. The aqueous symmetric cell fabricated of M@AC 1:5 with 6 M KOH electrolyte exhibits energy and power density 39.4 Wh kg?1 and 704.5 W kg?1 respectively. It shows long cycle stability with 90% capacitance retention and 100% coulombic efficiency even after 10,000 cycles. Further, the symmetric cell of M@AC 1:5 material was applied for lighting red LED, which illuminated for 22 min. The charging /discharging mechanism has been proposed based on finding of results through different characterizations. The asymmetric supercapacitor has also been designed using two different electrodes (first M@AC 1:5 and second synthetic MWCNT) and shows energy density of 14.9 Wh kg?1 and power density of 496 W kg?1 respectively. The capacitance retention is maintained up to 86.6% while coulombic efficiency recorded 100% for 10,000 cycles. Thus, obtained results highly encouraging and appropriate for the commercial applications. � 2021 Elsevier Ltd