Sol-Gel Preparation of Layered d-MnO2 Phase for Salt Removal by Hybrid Capacitive Deionization

Recent research on capacitive deionization (CDI) materials indicates that salt removal efficiency of their cells can be increased by modifying one carbon electrode, with an electrode operating through a redox mechanism.A potential candidate is δ-MnO2, due to its diverse crystalline phase structure, low price and environmental friendliness.This study synthesized the layered phase of δ-MnO2 via sol-gel route, targeting a high-performance electrode for hybrid CDI (HCDI) technology.Analyzes results on δ-MnO2 composition and porosity were verified through BET, Raman, SEM and X-RD measurements.Electrochemical properties confirmed pseudo-capacitance charge-storage of δ-MnO2 and high durability, with specific capacitance (Csp) of 143 F/g, at a rate of 1 A/g, remaining stable after 1000 cycles.Efficiency of salt removal by optimal performance active material, at 1.4 V, with a moderate salt adsorption capacity (SAC) of 22.5 mg/g, was investigated.