水热法制备二氧化锰及在过氧化氢传感器中的应用

Preparation of MnO_2 nanomaterials in hydrothermal method and applied in hydrogen peroxide sensing

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(MnO_2)催化剂,通过X射线衍射分析(XRD)、扫描电镜(SEM)以及N_2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-MnO_2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^(–6)mol/L(S/N=3)。

A series of manganese dioxide,namely urchinα-MnO2,α-MnO2nanowires andβ-MnO2nanorods were synthesized using hydrothermal method by changing raw materials such as KMnO4、MnSO4、Na2S2O8,etc.The MnO2materials were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),and N2adsorption-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 urchinα-MnO2nanowires based sensor exhibited the best electro catalytic activity towards the reduction of H2O2with a sensitivity of26.2μA·L/mmol.And the reduction peak currents of H2O2were linear to their concentrations in the range of2×10-6mol/L to0.14×10-3mol/L wih a lowest limit of detection of0.57×10-6mol/L(S/N=3).