Leaf‐Inspired Hetero‐Structure WS₂/WO₃ In Situ Embedded on Pomelo Peel Derived Carbon for Supercapacitor and Capacitive Deionization

Abstract

Composite materials have occupied a reliable position in electrochemical energy storage and conversion due to their double electric layer and pseudocapacitance. In this work, a leaf‐like heterostructure composite, obtained by peeling – carbonizing – in situ sulfuration/oxidation approach for the first time, is investigated as electrode material for electrochemical capacitance behavior. The thin and highly active transition metal WS2 acts as an energetic “blade” to trap free ions, which are then transported across the material through a strong “tendon skeleton” WO3. The derived carbon PPC with a large aspect ratio holds up the overall leaf structure, also as a “warehouse” for ion storage, thus enhancing the conductivity and wettability of the material. The above three (WS2+WO3+PPC) synergistically provide outstanding double‐layer capacitance and pseudocapacitance. In particular, the vacancy defects, constructed at the heterogenous interface from WS2‐WO3 in situ growth, can still achieve superior ion absorption/desorption ability even under large current density and high concentration brackish solution.