Characterization of performance and wear mechanism of diamond electrodes used for electrochemical oxidation of TCE

Boron-doped diamond (BDD) electrodes have shown tremendous promise for the oxidation of recalcitrant and complex waste streams through a combination of direct electron transfer at the electrode surface and indirect electron transfer mediated by hydroxyl radicals produced by water oxidation. However, little research has been dedicated to understanding the mechanisms associated with electrode wear and the effects of electrode wear on the mechanisms (direct vs. indirect) of contaminant oxidation. In this work, TCE is used as a model organic contaminant to investigate the relationship between electrode wear and the mechanisms of contaminant oxidation. Surface characterization (XPS, SEM, AFM) of the electrodes along with electrochemical impedance spectroscopy are used to correlate the electrode structure with measured TCE oxidation rates. This information will help to obtain a better understanding of the mechanisms associated with BDD electrode wear and will aid in the design of long-life electrodes.