Carregant...
Fitxers
Tipus de document
ArticleVersió
Versió acceptadaData de publicació
Llicència de publicació
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/147657
A hybrid photoelectrocatalytic/photoelectro-Fenton treatment of Indigo Carmine in acidic aqueous solution using TiO2 nanotube arrays as photoanode
Títol de la revista
Director/Tutor
ISSN de la revista
Títol del volum
Recurs relacionat
Resum
This article reports the synthesis of TiO2 nanotube arrays (TiO2 NTs), grown by Ti anodization, and their use as photoanode in a hybrid photelectrocatalytic (PEC)/photoelectro-Fenton (PEF) treatment of Indigo Carmine solutions in sulfate medium at pH 3.0. The anode was combined with an air-diffusion cathode that ensured continuous H2O2 electrogeneration. Comparative trials by electrochemical oxidation with electrogenerated H2O2 (EO-H2O2), electro-Fenton (EF) and PEF with Pt anode were made. The photoanode was stable operating up to 3 mA cm−2 with irradiation from a 36-W UV LED lamp, showing photoelectroactivity from an anodic potential (Ean) of +0.20 V, as determined by cyclic voltammetry. At 3 mA cm−2, color removal by EO-H2O2 with Pt and PEC with TiO2 NTs was very slow, being much faster in EF, PEF and PEC/PEF due to main role of OH formed from Fenton's reaction upon addition of Fe2+. The absorbance and dye concentration decays agreed with a pseudo-first-order kinetics, yielding a slightly lower rate constant for decolorization because of the formation of colored products. The mineralization ability increased as: EO-H2O2 ≪ EF ≪ PEF < PEC/PEF. The holes photogenerated at the TiO2 NTs surface had higher oxidation ability than OH formed at the Pt surface from water discharge. In PEC/PEF, a slower mineralization was found at 2 mA cm−2, although the final mineralization percentage was similar to that attained at 3 mA cm−2. Both, SO42− and NH4+ ions were released during the treatments, along with isatin-5-sulfonic and formic acids as main products.
Matèries (anglès)
Citació
Citació
ORIOL, Roger, SIRÉS SADORNIL, Ignacio, BRILLAS, Enric, RODRIGUES DE ANDRADE, Adalgisa. A hybrid photoelectrocatalytic/photoelectro-Fenton treatment of Indigo Carmine in acidic aqueous solution using TiO2 nanotube arrays as photoanode. _Journal of Electroanalytical Chemistry_. 2019. Vol. 847, núm. 113088. [consulta: 25 de febrer de 2026]. ISSN: 1572-6657. [Disponible a: https://hdl.handle.net/2445/147657]