Topochemically prepared tungsten disulfide nanostructures as a novel pseudocapacitive electrode for high performance...

The topochemical preparation of nanostructured materials (NMs) has received significant attention in recent years due to the exceptional electrochemical properties exhibited by the resulting NMs. This work focuses on the preparation of two-dimensional tungsten di-sulfide (WS₂) nanostructures through the topochemical conversion of tungsten trioxide (WO₃) nanostructures and also evaluates their potential applications as electrode materials for supercapacitors (SCs). The X-ray diffraction and photoelectron studies conducted in this research reveal the conversion of hexagonal WO₃ into hexagonal WS₂ nanosheets, accompanied by changes in oxidation states. The FE-SEM and HR-TEM studies confirm the formation of WS₂ in the sheet-like morphologies with lateral dimensions of 100 × 100 nm. The electrochemical investigation, using techniques such as CV, galvanostatic CD, and EIS, confirmed the presence of intercalation pseudocapacitance in the WS₂ electrode, with a higher electrode-specific-capacitance (260 F g^-1) than that of WO₃ electrode. The WS₂ symmetric SC delivered high device capacitance (59.17 F g^-1), energy density (8.21 Wh kg^-1) and power density (3,750 W kg^-1) with better cyclic stability over 5000 cycles. These experimental findings show that the topochemically synthesized WS₂as novel supercapacitor electrodes might be useful for the advancement of future-generation energy storage devices.