resumo
Hybrid multilayer films composed of poly(ethylenimine) and the Keggin-type polyoxometalates were prepared on glassy carbon electrodes by layer-by-layer self-assembly, and were characterized by cyclic voltammetry and scanning electron microscopy. UV-vis absorption spectroscopy of films deposited on quartz slides was used to monitor film growth, showing that the absorbance values at characteristic wavelengths of the multilayer films increase almost linearly with the number of bilayers. Cyclic voltammetry indicates that the electrochemical properties of the polyoxometalates are maintained in the multilayer films, and that the first tungsten reduction process for immobilized SiW11 and SiW11Co is a surface-confined process. Electron transfer to as electrochemical probes was also investigated by cyclic voltammetry. The (PEI/SiW11Co)(n) multilayer films showed excellent electrocatalytic reduction properties towards nitrite, bromate and iodate.
palavras-chave
GLASSY-CARBON ELECTRODES; KEGGIN-TYPE; ELECTROCHEMICAL-BEHAVIOR; POLYELECTROLYTE FILMS; TRANSITION-METAL; HOMOGENEOUS CATALYSIS; PASTE ELECTRODE; POLYOXOMETALATE; POLYOXOTUNGSTATES; SURFACES
categoria
Electrochemistry
autores
Fernandes, DM; Brett, CMA; Cavaleiro, AMV
nossos autores
Ana Maria Vieira Silva Viana Cavaleiro
Professor CatedráticoGrupos
agradecimentos
The authors thank the Fundacao para a Ciencia e a Tecnologia (FCT) for financial support (project POCI 2010-Feder-POCI/QUI/56534/2004). D. Fernandes acknowledges FCT for her PhD grant SFRH/BD/30797/2006. Thanks are also due to CICECO and the University of Aveiro.