Electrochemical Oxidation of Acid Violet 7 Dye by Using Si/BDD and Nb/BDD Electrodes

Autor(es)

Brito, Chrystiane N. ^[1] ; Ferreira, Maiara B. ^[1] ; Marcionilio, Suzana M. L. de O. ^[2] ; de Moura Santos, Elaine Cristina M. ^[1] ; Leon, Jose J. Linares ^[2] ; Ganiyu, Soliu O. ^[1] ; Martinez-Huitle, Carlos A. ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Univ Fed Rio Grande do Norte, Inst Quim, Lab Eletroquim Ambiental & Aplicada, BR-59078970 Natal, RN - Brazil

^[2] Univ Brasilia, Inst Quim, Lab Desenvolvimento Proc Quim, BR-70910900 Brasilia, DF - Brazil

^[3] Johannes Gutenberg Univ Mainz, Inst Organ Chem, D-55128 Mainz - Germany

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Electrochemical Society; v. 165, n. 5, p. E250-E255, 2018.
• Citações Web of Science: 4

Resumo

The electrochemical performance of thin film boron-doped diamond (BDD) electrodes deposited on either single crystal p-type Si (Si/BDD) or Nb (Nb/BDD) substrates have been investigated for the electrooxidation of azo-dye Acid Violet 7 (AV7). Both electrodes were characterized by linear voltammetry and the production of hydroxyl radicals ((OH)-O-center dot) at their surfaces was assessed by spin trap experiment using N, N-dimethyl-p-nitrosoaniline (RNO) as a spin trap molecule. Slightly higher O-2 evolution reaction (OER) potential was observed with Nb/BDD compared to Si/BDD in both 0.05 M Na2SO4 and AV7 solutions. Enhanced bleaching of RNO was always observed when an increased current density was applied and a significant decay of the adsorption band of RNO was attained with Nb/BDD compared to Si/BDD electrode, indicating higher generation of (OH)-O-center dot on its surface. Complete decolorization of 200 mg L-1 of AV7 was achieved with either electrodes at current density of 30 and 60 mA cm(-2) in 120 min or less. Quite similar degradation efficiency was attained at both electrodes but Si/BDD showed better results than Nb/BDD. Nevertheless, lower energy requirements was achieved by Nb/BDD, demonstrating that it can be a suitable electrode for an efficient electrochemical oxidation process. (C) 2018 The Electrochemical Society. (AU)

• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático