Carbon paste electrodes of the mixed oxide SiO2/Nb2O5 prepared by the sol–gel method: dissolved dioxygen sensor

Autor:	Maria Suzana P. Francisco, William S. Cardoso, Yoshitaka Gushikem
Rok vydání:	2005
Předmět:	General Chemical Engineering Inorganic chemistry chemistry.chemical_element Chronoamperometry Electrochemistry Analytical Chemistry Carbon paste electrode Electron transfer chemistry Electrode Mixed oxide Cyclic voltammetry Carbon
Zdroj:	Journal of Electroanalytical Chemistry. 574:291-297
ISSN:	1572-6657
DOI:	10.1016/j.jelechem.2004.08.010
Popis:	A carbon paste of SiO2/Nb2O5 material was used as the electrode in the development of a dissolved dioxygen sensor in 1.0 mol l−1 KCl solution at pH 6.2. The material was prepared by the sol–gel method. In the investigation of its electrochemical properties, linear and cyclic voltammetric and chronoamperometric techniques were employed. Dioxygen reduction, which was diffusion controlled, occurred at −280 mV vs. SCE by a two electron mechanism, producing peroxide. A linear response between the cathodic peak current intensity and the dissolved O2 concentration was obtained for the region between 1.0 and 13.6 mg l−1. The stability proved to be very good over successive voltammetric cycles. The electrode response time was about 5 s. The electron transfer reactions were explained as being to an n-type semiconductor of niobia dispersed in the silica surface.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ba175017bbb906a003e0abd93ceee8db https://doi.org/10.1016/j.jelechem.2004.08.010 Zobrazit plný text záznamu Full Text from ScienceDirect