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.