超声-浸渍法制备介孔MnO_2及其性质表征

采用超声-浸渍法,以SBA-15为硬模板、Mn(NO_3)_2为锰源制备出介孔MnO_2. 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MnO_2复制了SBA-15的介孔结构,比表面积、平均孔径分别为282m~2·g~(-1)和2.75nm;介孔MnO_2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).

Ultrasonic dipping synthesis and characterization of mesoporous MnO_2

A ultrasonic dipping method was used to prepared mesoporous MnO_2 with SBA-15 as a hard template and Mn(NO_3)_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). Galvanostatic charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were performed to investigate the electrochemical performance of the samples. The results indicated that the synthesized MnO_2 fabricated SBA-15 structure. The specific surface and mesopore size of the synthesized MnO_2 were 282m~2·g~(-1) and 2.75nm, respectively. As an electrode material of supercapacitors, mesoporous MnO_2 exhibited favorable reversible kinetic characteristics, low charge transfer resistance and high electrochemical activity, which had a initial specific capacitance of 285F·g~(-1) and retained at 210F·g~(-1) after 500 cycles.