α-MnO_2纳米线的微波法制备及其电化学性能研究

Microwave Assisted Synthesis ofα-MnO_2 Nanowires and Their Electrochemical Properties

以KMnO_4为锰源,在离子液体1-丁基-3甲基咪唑六氟磷酸盐[BMIM][PF_6]水溶液中通过微波加热法制备了α-MnO_2纳米线,并采用XRD和FESEM对产物的结构和形貌进行了表征。发现反应时间和离子液体对产物的形貌和尺寸起着关键作用,提出了反应机理。用循环伏安曲线、线性扫描曲线以及塔弗尔曲线在1mol/L的NaOH碱性溶液中研究了α-MnO_2的电化学性能。结果表明,90℃微波辐照1h所得到的纳米线形貌最均一,平均直径为15nm、平均长度为2μm,且具有良好的电化学性能,有望作为催化剂应用在燃料电池上。

A microwave-assisted heating process has been developed to synthesize α-MnO2 nanowires based on the decomposed reaction of KMnO4 in ionic liquid （[BMIM][PF6） aqueous solution. The product was characterized by X-ray diffraetion（XRD） and field emission scanning electron mieroscopy（FESEM）. It is found that the reaction temperature and ionic liquid are the key factors to determine the morphology and size. A plausible mechanism was pro posed to explain the formation of α-MnO2 nanowires. The electrochemical properties of the as-prepared samples were utilized by cyclic voltammetry curves, linear potential sweep curves, Tafel plots in lmol/L NaOH solution. The results show that α-MnO2 nanowires have the best morphology with a mean diameter of 15nm and a length of 2μm at 90℃ heating for 1h and the α-MnO2 exhibited excellent electrochemical characteristics. It＇s possible that the α-MnO2 can be used as a catalyst in fuel cells.