Enhancing Redox Activity and Surface Reactivity via Incorporation of Hierarchical MoO3 Nanobelts into Layered WS2 Nanosheets for High-Performance Symmetric and Asymmetric Supercapacitors

Abstract

This study aims to develop a redox-active molybdenum trioxide incorporated tungsten disulfide (WS2/MoO3) nanocomposite electrode, synthesized via a facile hydrothermal method, and assessed for both symmetric and asymmetric supercapacitor applications. The influence of varying MoO3 content (0, 1, 3, 5, and 7 wt.%) on the surface morphology, structural properties, and electrochemical performance of WS2 nanosheets was systematically investigated using comprehensive characterization techniques. The resulting hierarchical 2D–1D heterostructure offers enhanced redox activity, increased surface reactivity, and a defect-enriched interface. Electrochemical measurements revealed a specific capacitance of 715 F g-1 at 0.5 A g-1, with excellent cycling stability, retaining 85% of its initial capacitance after 6,000 charge-discharge cycles at a high current density of 12 A g-1. The symmetric WS2/MoO3//WS2/MoO3 cell exhibited surface-controlled capacitive behavior, leading to superior rate capability. Furthermore, the asymmetric WS2/MoO3//AC supercapacitor achieved an energy density of 37.1 W h kg-1 at a power density of 1.23 kW kg-1 and could maintain 20.3 W h kg-1 under a high-power density of 5.63 kW kg-1, highlighting its potential for high-performance energy storage applications.