Effect of MoS2 and electrolyte temperature on the electrochemical performance of NiCoS@rGO-based electrode material for energy storage, oxygen reduction reaction and electrochemical glucose sensor

Abstract

Two-dimensional transition metal dichalcogenides (2D-TMDs) are essential in energy storage devices. MoS2/rGO nanostructures have improved energy storage capacity because of their layered shape, proximity effect, inherent broad surface area, and edge locations. Herein, we have synthesized NiCoS@MoS2@rGO composite electrode material for supercapattery energy storage devices and electrochemical glucose sensors via the hydrothermal method. The electrochemical performance of NiCoS, NiCoS@MoS2 and NiCoS@MoS2@rGO were first investigated in three electrode assemblies at different electrolyte temperatures (27 °C to 50 °C). Among all the samples, NiCoS@MoS2@rGO shows the superior value of Qs (1138C/g or 1896.66 F/g) with 1 M KOH electrolyte solution at 50 °C. The asymmetric NiCoS@MoS2@rGO//AC device showed a high specific capacity (301C/g, at 1 A/g), energy and power densities of 65.44 (Wh/Kg), and 1267.18 (W/Kg), respectively. A significant value of Coulombic efficiency of 92.79 % and capacity retention of 83.42 % was acquired after 5000 galvanostatic charging/discharging (GCD) cycles. Further, the NiCoS@MoS2@rGO nanocomposite electrode material is used for oxygen reduction reaction activity. The initial potential for the oxygen reduction was 0.67 V vs. RHE, and the electrode showed high stability. Besides, the hybrid device is used as an electrochemical glucose sensor to detect glucose with a highly precise detection response. This research will open new ideas for developing more efficient TMDs sulfide-based nanocomposite materials for future energy storage systems and biomedical applications.