Ultrasonic dipping synthesis and characterization of mesoporous MnO₂

A ultrasonic dipping method was used to prepared mesoporous MnO₂ with SBA-15 as a hard template and Mn(NO₃)₂ as a Mn source. The texture/structures of the samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), nitrogen adsorption-desorption and thermogravimetry-differential thermal analysis (TG/DTA). Galvanostatie charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were performed to investigate the electrochemical performanee of the samples. The results indicated that the synthesized MnO₂ fabricated SBA-15 structure. The specific surface and mesopore size of the synthesized MnO₂ were 282 m²·g^-1 and 2.75 nm, respectively. As an electrode material of supercapaeitors, mesoporous MnO₂ exhibited favorable reversible kinetic characteristics, low charge transfer resistance and high electrochemical activity, which had a initial specific capacitance of 285 F·g^-1 and retained at 210 F·g^-1 after 500 cycles.