α-MnO_2和β-MnO_2一维材料的可控制备及其电容性能  

Controlled Preparation of α-MnO_2 and β-MnO_2 Materials with One-Dimensional Structure and Its Capacitive Performances

作　　者：朱刚[1] 段淑娥[1] 赵彤 戴琪 ZHU Gang;DUAN Shu-e;ZHAO Tong;DAI Qi(School of Chemical Engineering,Xi'an University,Xi'an 710065,China)

机构地区：[1]西安文理学院化学工程学院,西安710065

出　　处：《人工晶体学报》2018年第8期1675-1679,共5页Journal of Synthetic Crystals

基　　金：西安市科技计划项目(2016CXWL08);2017年国家级大学生创新创业训练计划项目(201711080018)

摘　　要：将锰粉分散在K_2S_2O_8水溶液中,分别在150℃和180℃水热处理24 h制备了两种MnO_2材料。应用X-射线衍射(XRD)、扫描电镜(SEM)和N2吸-脱附技术对所得产物进行表征。结果表明,α-MnO_2具有纳米线状形貌(直径为40~60 nm,长度约为4μm),β-MnO_2具有棒状形貌(长度约为3μm)。α-MnO_2的比表面积高达87 m2/g,而β-MnO_2的仅为6.2 m2/g。电化学测试结果表明,在1 mol/L Na2SO4水溶液中,当扫描速度为5 m V/s时,α-MnO_2和β-MnO_2的比电容分别为121 F/g和19 F/g。扫速为20 m V/s时,α-MnO_2循环2000次后的容量保持率高达99.2%。α-MnO_2具有优异的电容性能。Two kinds of MnO 2 were prepared by hydrothermally treating the suspension of K 2 S 2 O 8(water as dispersant)and Mn powder at 150℃and 180℃for 24 h,respectively.The physicochemical characterization of the obtained products was proceeded by X-ray diffraction(XRD),scanning electron microscopy(SEM)and N 2 adsorption-desorption.SEM results show thatα-MnO 2 consists of nanowires with diameter of approximately 40-60 nm and length of about 4μm;whileβ-MnO 2 displays a rod-like shape with the length of around 3μm.N 2 adsorption-desorption results reveal that the surface area ofα-MnO 2(87 m 2/g)is much higher than that ofβ-MnO 2(6.2 m 2/g).Electrochemical characterization indicates thatα-MnO 2 andβ-MnO 2 electrodes exhibit specific capacitances of 121 F/g and 19 F/g in 1 mol/L Na 2 SO 4 aqueous solution at 5 mV/s,separately.The cycling performance ofα-MnO 2 has revealed capacitance retention of 99.2%after 2000 cycles at 20 mV/s.α-MnO 2 shows excellent capacitive performance.

关 键 词：锰粉 二氧化锰 水热制备 电容性能 

分 类 号：O614.711[理学—无机化学]