Effect of the sp3/sp2 Ratio in Boron‐Doped Diamond Electrodes on the Degradation Pathway of Aniline by Anodic Oxidation

Abstract The sp 3 /sp 2 ratio present in boron‐doped diamond (BDD) electrodes conditions the way in which organic compounds are oxidized and transformed to CO 2 during anodic oxidation. A higher content of sp 3 carbon on the surface favors the generation of hydroxyl radicals over the oxygen evolution reaction, which generates different degradation byproducts. In this work, we studied the degradation of aniline by anodic oxidation using five BDD electrodes with different sp 3 /sp 2 ratios in sulfate and chloride media. Aniline was degraded using the five BDD electrodes in both electrolytes, and clear differences were observed in the intermediates produced during the electrolysis. BDD electrodes with higher sp 3 proportions allowed for greater degradation and mineralization of aniline with lower molecular weight and the production of fewer toxic organic byproducts. Degradation pathways for aniline in sulfate and chloride media are proposed, evidencing the differences in the oxidation mechanisms for aniline and its byproducts due to the varying sp 3 /sp 2 ratio in the BDD electrodes.