Photoelectrocatalytic Oxidation of Sulfamethazine on TiO2 Electrodes

The photoelectrocatalytic degradation and mineralization of sulfamethazine (SMT), a sulfonamide drug, were explored in aqueous solution. Working electrodes with TiO2 coatings on Ti substrates (TiO2/Ti) used, which produced by the dip coating method. film analyzed scanning electron microscopy (SEM) X-ray diffraction (XRD) following annealing at 500 °C for 1.5 h. To photoelectrochemically characterize them, photocurrents vs. applied potential curves used. efficiency (PEC) TiO2/Ti regarding oxidation SMT has been assessed reference to under different experimental conditions. selected drug molecule was effectively degraded Langmuir–Hinshelwood (L-H) kinetic model. shown increase increasing bias up +1.5 V Ag/AgCl. It found be more favorable acidic environments compared alkaline ones. A decrease destruction rate constant recorded when pH increased from 3 5.6 (natural pH) 9. decomposition first subsequently reach saturation value high concentrations SMT, indicating that also depends other parameters (e.g., charge or mass transfer electrode double layer). results experiments those electrochemical (EC) photocatalytic (PC) SMT. significant enhancement case PEC degradation, leading an apparent constants k, mineralization, kTOC, 153 298%, respectively, simple process.