ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photocatalytically-assisted electrochemical degradation of p-aminophenol in aqueous solutions using zeolite-supported TiO₂ catalyst

Cornelia Ratiu, Florica Manea, Carmen Lazau, Corina Orha, Georgeta Burtica, Ioan Grozescu, and Joop Schoonman

Department of Condensed Matter, National Institute of Research-Development for Electrochemistry and Condensed Matter Timisoara, Plautius Andronescu 1, 300224 Timisoara, Romania

E-mail: cornelia_ratiu@icmct.uvt.ro

Abstract: This paper reports the results of an investigation into enhancement of the electrochemical oxidation of p-aminophenol (4-AP) in an aqueous solution with a boron-doped diamond (BDD) electrode, assisted by photocatalysis using a zeolite-supported TiO₂ (Z-TiO₂) catalyst. The BDD electrode was characterised in 0.1 M Na₂SO₄-supporting electrolyte and the presence of 4-AP by open-circuit potential behaviour (OCP) and cyclic voltammetry (CV). The electrode behaviour was investigated in the dark and following UV irradiation and in the absence/presence of the Z-TiO₂ catalyst. The electro-oxidation process was carried out using chronoamperometry (CA) and multiple-pulsed amperometry (MPA) at the selected potential under potentiostatic conditions. The electrochemical degradation process of 4-AP on the BDD electrode was improved by the application of a pulsed potential, which allowed both in-situ electrochemical cleaning of the electrode and indirect oxidation of 4-AP by oxygen evolution. The application of photocatalysis using Z-TiO₂ in the 4-AP electrochemical degradation exhibited an enhanced effect when the anodic potential was set at +1.25 V vs. Ag/AgCl in the water stability region, close to the oxygen evolution potential.

Keywords: p-aminophenol removal – electrochemical oxidation – photocatalytically-assisted electrochemical oxidation – zeolite-supported TiO2

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0009-2

Chemical Papers 65 (3) 289–298 (2011)