十二烷基苯磺酸钠对MnO_2电化学性能影响的研究

Effect of dodecylbenzenesulfonate on the electrochemical performance of the MnO_2

在表面活性剂十二烷基苯磺酸钠(SDBS)存在下,采用液相共沉淀法制备了二氧化锰(MnO2)电极材料,研究了SDBS对其结构、形貌和电化学性能的影响。利用傅利叶变换红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)对所制备MnO2结构和形貌进行了表征。在1mol/L Na2SO4溶液中,通过循环伏安法(CV)、恒电流充放电(CD)和交流阻抗法(EIS)测试了电极材料的电化学性能。结果表明,SDBS对MnO2的晶型无明显影响,但使其粒径尺寸减小,形貌发生变化。MnO2的比电容随SDBS浓度的增加先增大后减小,SDBS浓度为0.023mol/L时制得的MnO2比电容可达193F/g(电流密度为1A/g),而不加SDBS时制得的MnO2比电容为156F/g。

In this paper,manganese oxide(MnO2)nanostructures were synthesized by fluid co-precipitation method with surfactant sodium dodecylbenzenesulfonate(SDBS).The effect of SDBS on the structure,morphology and electrochemical performance of the as prepared MnO2 was studied.The structure and morphology of the products were characterized by Fourier transform infrared spectrum(FT-IR),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The electrochemical properties of the as prepared MnO2 were investigated by cyclic voltammetry(CV),galvanostatic charge-discharge(CD)test and electrochemical impedance spectroscopy(EIS)in 1 mol/L Na2SO4 aqueous electrolyte.The results showed that SDBS had no significant influence on the crystal structure of the as prepared MnO2,but made the size of the as prepared MnO2 smaller.As the concentration of SDBS increased,the specific capacitance of the as-obtained MnO2 first increased and then decreased,and 0.023mol/L was found to be the optimum impact concentration of SDBS.The MnO2 synthesized under optimum concentration delived a high specific capacitance of 193F/g at the current density of1A/g,compared to the 156F/g of the MnO2 synthesized without surfactant.