微球状Co_3O_4修饰电极检测邻苯二酚

Determination of catechol by using Co_3O_4 microsphere modified electrode

采用水热法在400℃的条件下煅烧并形成Co_3O_4微球,通过XRD粉末衍射、SEM等对Co_3O_4结构及形貌进行表征,并用循环伏安法(Cyclic Voltammetry,CV)和电化学阻抗谱法(Electrochemical Impedance Spectroscopy,EIS)对Co_3O_4的电化学性能进行表征。利用Co_3O_4修饰玻碳电极(Co_3O_4/GCE)并通过方波伏安法(Square wave voltammetry,SWV)检测邻苯二酚,在3.3~33μmol/L的浓度范围内,邻苯二酚浓度和峰电流值呈线性关系,回归方程的相关系数为0.995,检测限(LOD)为0.42μmol/L(3σ法),灵敏度为0.029μA·(μmol/L)-1。同时进行了电极的稳定性实验,经10次循环,其峰电流的相对标准偏差(RSD)为0.25%。还对实际水样进行加标回收实验,该电极对实际水样的检测呈现出良好的性能。

The Co3O4 microspheres are synthesized through hydrothermal method calcining at 400℃. The structure and morphology of Co3O4 microspheres obtained are characterized by X-ray power diffraction（XRD） and scanning electronic microscopy（SEM）. The electrochemical performances of Co3O4 microspheres are characterized by cyclic voltammetry（CV） and electrochemical impedance spectroscopy（EIS）. Glassy carbon electrode（GCE） is modified by Co3O4 microspheres.Then Co3O4/GCE electrode is used to detect catechol by square wave voltammetry（SWV） method.Results show that if the concentration of catechol is in the range of 3. 3 μmol·L-1to 33 μmol·L-1,the concentration of catechol is linear with peak current value with the correlation coefficient of regression equation being 0. 995.The detection limit is 0. 42 μmol·L^-1（3σ method） and the sensitivity is 0. 029 μA·（μmol/L）^-1.Besides,the stability of Co3O4/GCE electrode is also detected through experiments,and results indicate that the relative standard deviation（RSD） for peak current is 0. 25% after 10 cycles. It is also applied to the determination of catechol in real water samples using the standard addition method and exhibits a good performance as well.