Estudio de la degradación de diclofenaco en medio acuoso mediante fotoelectrocatálisis empleando un fotoánodo de diamante dopado con boro (BDD) modificado con dióxido de titanio (TiO2)

Abstract

This work presents the study of the diclofenac degradation by photoelectrocatalysis (PEC), using a boron-doped diamond modified with titanium dioxide photoanode (TiO2/BDD), which is obtained by electrophoretic deposition method.

For electrophoretic deposition, the concentration of TiO2 in suspension and deposition time were analyzed. It was determined that a suspension of 2,5% W/V of TiO2 in isopropyl alcohol at 2,5% V/V and 15 s of deposition time are required for the photoanode preparation. The characterization suggests that the TiO2 film increases the electroactive area and consequently the oxidation capacity of the electrode. The diclofenac degradation is compared by photoelectrocatalysis (FEC) and electrooxidation (EO) in 25 ppm solutions. In two hours of treatment using FEC with UV-C light and a current density of 2,2 mA cm-2, 98,5% degradation and 80,1% mineralization were achieved; while, through EO, 85,6% degradation and 76,1% mineralization were achieved, with twice the current density (4,4 mA cm-2). Therefore, the PEC is more efficient than EO process both in degradation and in energy consumption.