超声-浸渍法制备介孔MnO_2及其性质表征

Ultrasonic dipping synthesis and characterization of mesoporous MnO_2

采用超声-浸渍法,以SBA-15为硬模板、Mn(NO3)2为锰源制备出介孔MnO2.采用X射线衍射(XRD)、扫描电镜(SEM)、氮气吸附-脱附以及热重-差热方法(TG/DTA)对样品的物理结构进行表征;用恒流充放电、循环伏安和电化学阻抗(EIS)考察样品作为超级电容器电极材料的性能.结果表明,样品MnO2复制了SBA-15的介孔结构,比表面积、平均孔径分别为282m2.g-1和2.75nm;介孔MnO2作为超级电容器电极材料,具有良好的动力学可逆性,电荷转移电阻小,电化学活性较高,首次放电比容量为285F.g-1,循环500次后仍保持在210F.g-1.

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 m^2 ·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.