Perspective on ultrathin layered Ni-doped MoS2 hybrid nanostructures for the enhancement of electrochemical properties in supercapacitors

Over the last two decades, extensive study has been done on two-dimensional Molybdenum Sulphide (MoS2) due to its outstanding features in energy storage applications. Although MoS2 has a lot of active sulphur edges, the presence of inactive surfaces leads to limit conductivity and efficiency. Hence, in this article, we aimed to promote the additional active sites by doping various weight percentages (2%, 4%, 6%, 8% and 10%) of Nickel (Ni) into the MoS2 matrix by simple hydrothermal technique, and their doping effects were investigated with the help of Physio-chemical analyses. X-ray diffraction (XRD) pattern, Raman, and chemical composition (XPS) analyses were used to confirm the Ni incorporation in MoS2 nanosheets. Microscopic investigations demonstrated that Ni-doped MoS2 nanosheets were vertically aligned with enhanced interlayer spacing. Cyclic voltammetry, Galvanostatic charge-discharge, and elec-trochemical impedance spectroscopy investigations were used to characterize the electrochemical char-acteristics. The 6% Ni-doped MoS2 electrode material showed better CSP of 528.7 F/g @ 1 A/g and excellent electrochemical stability (85% of capacitance retention after 10,000 cycles at 5 A/g) compared to other electrode materials. Furthermore, the solid-state asymmetric supercapacitor was assembled using Ni-doped MoS2 and graphite as anode and cathode materials and analysed the electrochemical properties in the two-electrode system. To determine the impact of the Ni-atom on the MoS2 surface, first -principles computations were performed. Further, it was examined for electronic band structure, the pro-jected density of states (PDOS) and Bader charge transfer analyses.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This article investigates the doping effects on two-dimensional Molybdenum Sulphide (MoS2) to improve conductivity and efficiency. Different weight percentages (2%, 4%, 6%, 8%, 10%) of Nickel (Ni) were doped into the MoS2 matrix using a simple hydrothermal technique, and their effects were studied using physio-chemical analyses. The results show that Ni-doped MoS2 nanosheets exhibit enhanced interlayer spacing and the 6% Ni-doped MoS2 electrode material shows better electrochemical performance.