Cavity-like hierarchical architecture of WS2/α-NiMoO4 electrodes for supercapacitor application

Abstract

In this study, we fabricated a nano/micro cavity-like hierarchical architecture of WS2/α-NiMoO4 composite using microwave hydrothermal and calcination processes. The composite was characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, and X-ray photoelectron spectroscopy. The electrochemical measurements of the WS2/α-NiMoO4 composite electrode for application in supercapacitors (SCs) were performed through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The WS2/α-NiMoO4 nanocomposite exhibited a specific capacity of 460 F g-1 at 1 A g-1 current density and a capacitor retention of 92% after 2000 cycles. However, α-NiMoO4 spherical nanoparticles had a specific capacity of 231 F g-1 at 1 A g-1 current density and capacitor retention of 73% after 2000 cycles. The excellent specific area, formation of cavity-like structures, increase in pore size, superior electrical conductivity, and robust stability of WS2/α-NiMoO4 enhanced the effectiveness of the electrode composite material for supercapacitor application.