水热法制备纳米MnO2及其赝电容性能研究

摘要

Nanostuctured MnO2 with different morphology were prepared via a hydhothermal method at 120℃ and different dwell time,which K2S2O8 was oxidizing agent and MnSO4 was Mn source.The products were characterized by powder X-ray diffraction (XRD),scanning electron microscopy(SEM).The pseudocapacitive properties of nanostuctured MnO2 were investigated by cyclic voltammetry,AC impedance and galvanostatic charging/discharging test.The results showed that the morphology of as-prepared MnO2 changed from microspheres withurchin-like nanostructure into dispersive nanowires with the increase of the dwell time from 12h to 36 h.And the specific capacitance of the single electrode decreased from 282F·g-1 for the sample at 12h to 161F·g-1 for the sample at 24h,then increased to 203F·g-1 for the sample at 36h.%本文K2S2O8作氧化剂,以MnSO4为锰源,于120℃不同水热反应时间下制备得到不同形貌的纳米MnO2,用X射线衍射(XRD)和扫描电镜(SEM)对样品的结构与形貌进行表征.采用循环伏安法、交流阻抗和恒流充放电技术对纳米MnO2赝电容性能进行测试.结果表明,随着反应时间的增加,纳米MnO2形貌由海胆结构转变为纳米线,水热处理12 h时纳米MnO2比电容为282 F·g-1,水热处理时间延长至24h时比电容下降为161 F·g-1,继续反应至36 h比电容又上升为203 F·g-1.