Artículos de revistas
Carbon paste electrodes of the mixed oxide SiO2/Nb2O5 prepared by the sol-gel method: dissolved dioxygen sensor
Registro en:
Journal Of Electroanalytical Chemistry. Elsevier Science Sa, v. 574, n. 2, n. 291, n. 297, 2005.
0022-0728
WOS:000225755600009
10.1016/j.jelechem.2004.08.010
Autor
Francisco, MSP
Cardoso, WS
Gushikem, Y
Institución
Resumen
A carbon paste of SiO2/Nb2O5 material was used as the electrode in the development of a dissolved dioxygen sensor in 1.0 mol1(-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 02 concentration was obtained for the region between 1.0 and 13.6 mg1(-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. (C) 2004 Elsevier B.V. All rights reserved. 574 2 291 297