电活化玻碳电极作为苯酚伏安传感器的研究

玻碳电极在0.5mol.L-1硫酸溶液中以恒电位法在＋1.7V（vs.Ag/AgCl）电位阳极氧化400s得到电活化玻碳电极。采用循环伏安法和差分脉冲伏安法对苯酚在电活化玻碳电极上的电化学行为进行了研究。结果发现,在pH值7.0的磷酸盐缓冲溶液中,苯酚在0.75V（vs.Ag/AgCl）处有一良好的氧化峰,在0.02～0.10V.s-1范围内,其氧化峰电流与扫描速率呈良好线性关系,表明电极过程为受吸附控制的不可逆过程;氧化峰电流（Ip）与苯酚浓度在1×10-6～1×10-4 mol.L-1范围内呈良好的线性关系（R=0.9852）,检出限为6.0×10-7 mol.L-1（S/N=3）。并应用此法分析了自来水中苯酚的含量。

Study on Electro-Activated Glassy Carbon Electrode as A Voltammetric Sensor for Phenol

Electrochemical behavior of phenol at electro-activated glassy carbon electrode（EGCE） was studied by cyclic voltammetry（CV） and differential pulse voltammetry（DPV）.The glassy carbon electrode（GCE） was activated in 0.5 mol·L-1 H2SO4 solution for 400 s by potentiostatic method at the potential ＋1.7 V（vs.Ag/AgCl）.In a PB solution with pH value of 7.0,a well defined oxidative peak of phenol was observed at 0.75 V（vs.Ag/AgCl） with the activated electrode,the oxidation peak current was linear over the scanning speed in the range of 0.02～0.10 V·s-1,indicating the electrode process of phenol was irreversible and phenol controlled by adsorption.Experimental parameters were optimized and the correlation between peak current（Ip） and concentration was studied by DPV.Under the optimal conditions,the calibration curve showed a good linearity between the oxidation peak current（Ip） and phenol concentration in the range of 1×10-6～1×10-4 mol·L-1（R=0.9852） with a detection limit of 6.0×10-7 mol·L-1（S/N=3）.The proposed method was used to determine phenol content in tap water samples.