Preparation and electrochemical behavior of the CA/TiO2/Sb2O5 composite electrode modified with p-benzoquinone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In this present study, a novel material made up of p-benzoquinone (BQ) immobilized on a new composite of cellulose acetate and mixed metal oxides (CA/TiO2/Sb2O5) was applied to the electrocatalytic oxidation of ascorbic acid (H(2)AA). The material was prepared by a phase inversion process and characterized by several techniques including scanning electronic microscopy coupled with energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence. Ti and Sb mapping profiles on the surface showed a homogeneous distribution of the matrices. Ti-2p and Sb-3d doublet indicate that the formation of TiO2 and Sb2O5 is the presumed responsible for the good rigidity of the polymeric matrix. A carbon paste electrode of this material was used to study the electrocatalytic oxidation of ascorbic acid by cyclic voltammetric, chronoamperometric and differential pulse techniques. The electrode had a quick response time, showing great potential to be utilized as an electrochemical sensor for the determination of ascorbic acid in commercial samples. (C) 2012 Elsevier B.V. All rights reserved.6907482Pro-Reitoria de Pesquisa da Universidade Federal do Rio Grande do Sul (Propesq-UFRGS)Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministerio de Ciencia e Tecnologia (MCT)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq