Leaf‐Inspired Hetero‐Structure WS 2 /WO 3 In Situ Embedded on Pomelo Peel Derived Carbon for Supercapacitor and Capacitive Deionization

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.