Abstract: A series of manganese dioxide,namely urchin α-MnO₂,α-MnO₂ nanowires and β-MnO₂ nanorods were synthesized using hydrothermal method by changing raw materials such as KMnO₄、MnSO₄、Na₂S₂O₈,etc. The MnO₂ materials were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),and N₂ adsorption-desorption measurements. A novel hydrogen peroxide (H₂O₂)sensor was fabricated by coating the mixture of Nafion and nanomaterials on a glassy carbon electrode(GCE). The performances of the modified electrode was investigated using cyclic voltammetry(CV)and chronoamperometry current-time response(I-t). The test results indicated that the urchin α-MnO₂ nanowires based sensor exhibited the best electro catalytic activity towards the reduction of H₂O₂ with a sensitivity of 26.2μA·L/mmol. And the reduction peak currents of H₂O₂ were linear to their concentrations in the range of 2×10^-6mol/L to 0.14×10^-3mol/L wih a lowest limit of detection of 0.57×10^-6mol/L(S/N=3).

Key words: manganese oxide, hydrothermal method, Nafion, hydrogen peroxide (H₂O₂), electrochemical sensor

摘要： 以高锰酸钾、硫酸锰、过硫酸钠等为原料，采用水热法合成了一系列二氧化锰（MnO₂）催化剂，通过X射线衍射分析（XRD）、扫描电镜（SEM）以及N₂吸附-脱附等手段进行了表征。后将一定量的二氧化锰材料与Nafion混合后滴涂于玻碳电极（GCE）表面，构成了一系列新型的过氧化氢传感器。并采用循环伏安法（CV）和计时电流法（I-t）分别对修饰电极进行表征，考察其相应的传感性能。结果表明，海胆状α-MnO₂催化剂修饰的玻碳电极对过氧化氢有优异的电催化性能，其灵敏度为26.2μA·L/mmol。H₂O₂峰电流值在（2×10^-6）~（0.14×10^-3）mol/L范围内与浓度呈线性关系，最低检出限为0.57×10^-6mol/L（S/N=3）。

关键词: 二氧化锰, 水热法, Nafion, 过氧化氢, 电化学传感器