Preparation, characterization, and electrochemical evaluation of nickel sulphide on lignin-derived carbon material for supercapacitors
Violet Moagi, L.F. Mabena, M.V. Maphoru Tshwane University of Technology, South Africa
Porous carbon is the main important component in energy storage systems. The production procedures for carbon materials should be cost-effective and use renewable materials, which is considered a green approach to producing energy [1]. Supercapacitors (SCs) have been of interest due to their high-power density, rapid charge/ discharge, and long life [2] but they are disadvantaged by their low energy density [1], which can be improved by promoting the specific capacitance of electrode materials. The improvement of carbon-based materials has little effect hence there is a focus on the development of transitional metal sulphides such as nickel sulphide (NiS) as electrode materials for electrochemical performances. In this study, lignin was successfully extracted by H 2 SO 4 and used to prepare activated carbon. NiS nanoparticles and NiS/L-AC are prepared by a power-controlled microwave. All materials were characterized by FTIR, TGA, BET, XRD, SEM, and TEM and electrochemically analysed by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. Figure 1(A) The XRD pattern of NiS/L-AC showed sharp intense peaks of highly crystalline NiS and a broad peak at 24 o ,which is indexed by (002) and is attributed to the amorphous structure of carbon from L-AC. Figure 1(B) CV curves of NiS NPs, L-AC and NiS/L-AC 7 at a scan rate of 100 mV s −1 with specific capacitance of 590.9, 197.8 and 701.7 F g -1 respectively. These CV curves remain in good rectangular shapes even at higher scan rates, which displays a good current response and a good charge separation.
Figure 1: (a) XRD graph and (b) CV curves of L-AC 750 o C, NiS NPs and NiS/AC 750 o C References
1. Hung, T.-F.; Yin, Z.-W.; Betzler, S. B.; Zheng, W.; Yang, J. & Zheng, H. Nickel Sulfide Nanostructures Prepared by Laser Irradiation for Efficient Electrocatalytic Hydrogen Evolution Reaction and Supercapacitors. Chemical Engineering Journal 2019 , 367 , 115-122. 2. Li, Q.; Horn, M.; Wang, Y.; Macleod, J.; Motta, N.& Liu, J. A Review of Supercapacitors Based on Graphene and Redox- Active Organic Materials. Materials (Basel) 2019 , 12 .
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© The Author(s), 2022
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