Structure Engineering of WS₂@Carbon Nanofibers for CO₂ Capture, Supercapacitors, and Na-Ion Storage

Abstract

Two-dimensional ultrathin nanosheets of layered transition metal dichalcogenides (TMDCs) on flexible substrates like carbon nanofibers (CNF) are fundamentally and technologically intriguing structures. Nowadays, the main challenges are flexibility, high rate capability, porosity, and stability. The flexible 2D-layered TMDCs are created by exfoliating bulk materials on flexible CNF with controlled composition, structure, and dimensionality. Layering electroactive materials on mechanically durable, porous, chemically stable, and electrically conductive networks can successfully address these difficulties. As proven in this work, the tunable porosity and flexible design of heterophase IT/2H TMDC@CNF [tungsten disulfide on CNF (WS 2 @CNF)] are useful for a range of applications. These unique characteristics of the WS 2 @CNF heterophase structure adsorb 2.1 mmol/g of CO 2 at 1.0 bar, and supercapacitor electrochemical studies show good performance with a specific capacitance of 294 F/g at a current density of 2 A/g. Furthermore, these flexible binder-free sodium-ion (NIBs) electrodes have exceptional electrochemical properties, with WS 2 @CNF achieving a remarkable specific capacity of 300 mA h/g and an initial Coulombic efficiency of 80% at 300 cycles.