纳米类仙人球状MnO2的合成与超级电容器性能

Synthesis of ball-cactus-like nanostructured α-MnO_2 and supercapacitor performance

通过简单的化学法首次合成了均一的琢α-MnO2类仙人球状纳米球。通过X射线衍射分析(XRD),扫描电镜(SEM)和热重分析(TG)对产品进行了表征。XRD结果显示产品是无定形琢α-MnO2。SEM测试表明产品为纳米类仙人球形貌。合成产品的最佳制备条件为:反应温度60℃,反应时间3 h,KMnO4和H2C2O4配比是2∶3。把产品在400℃下恒温热处理2 h后,比电容高达265 F/g。这可能归因于它有着独一无二的类仙人球状纳米结构。

In this work, homogeneous nanostructured ball-cactus-like α-MnO2 was first synthesized via a simple chemistry route. The products were characterized by power X-ray diffraction （XRD）, scanning electron microscopy （SEM） and thermogravimetric （TG）. The XRD results indicate that the product is amorphous α-MnO2. The SEM pictures show that the morphologies of the product are nanostructured ball-cactus-like. The optimal prepared conditions are as follows： reaction temperature is 60 ℃, reaction time is 3 h and the molar ratio is KMnO4 ： H2C2O4=2 ： 3. The specific capacitance is up to 265 F/g, when the product is heat-treated at 400 ℃ for 2 h. This may be attributed to the unique nanostructure of ball-cactus-like α-MnO2.