Anodic oxidation of aspirin on PbO2, BDD and porous Ti/BDD electrodes: Mechanism, kinetics and utilization rate

The electrochemical abatement of aspirin, a representative anti-inflammatory drug, is carried out through anodic oxidation by employing PbO 2 , boron-doped diamond (BDD) and porous Ti/BDD as anodes. The effect of nature characteristic and structure of the electrode material on the electrochemical oxidation is systematic investigated. The redox behavior of aspirin on different electrodes is studied by linear sweep voltammetry. Completely mineralization of aspirin could be achieved on BDD electrodes. The results show that the electrochemical incineration of aspirin on three electrodes follows a pseudo first-order kinetics behavior with apparent rate constant of 0.051, 0.185 and 0.367   h −1 for PbO 2 , flat BDD and porous BDD electrode. Electrochemical degradation mechanism on BDD electrodes involves the direct and indirect electrochemical oxidation while there is only indirect oxidation for aspirin on PbO 2 electrode. Porous Ti/BDD presents the best excellent electrochemical oxidation ability for aspirin compared with flat BDD and PbO 2 electrode. The discrepancy of electrochemical oxidation could be explained in terms of in situ generation and utilization rate of hydroxyl radicals on the surface of electrode materials.