Electrochemical impedance spectroscopy of dichlorophenols at boron-doped diamond electrodes

Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrocatalytic process of boron-doped diamond (BDD) electrode with 2,4-dichlorophenol (2,4-DCP) and 2,6-dichlorophenol (2,6-DCP) as target pollutants. Results showed that the oxidation potential of the 2,4-DCP and 2,6-DCP were 1.55 and 1.62 V, respectively. Equivalent circuit simulation results showed that the charge transfer resistance for the two DCPs were both decreased when the polarization potential increased from open circuit potential to 1.5 V, indicating that electrocatalytic oxidation was favored by increasing potential. The diffusion step was the control step at oxidation potential. The indirect electrochemical oxidation of 2,4-DCP occurred more easily at BDD electrode than 2,6-DCP.