1. Electrostatic immobilization of polyoxometallates on silicon: X-ray Photoelectron Spectroscopy and electrochemical studies
- Author
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Fleury, Benoit, Billon, Martial, Duclairoir, Florence, Dubois, Lionel, Fanton, Aurélien, and Bidan, Gérard
- Subjects
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POLYOXOMETALATES , *ELECTROCHEMICAL analysis , *X-ray photoelectron spectroscopy , *ELECTROSTATICS , *PROTON transfer reactions , *VOLTAMMETRY - Abstract
Abstract: Keggin-type dodecatungstosilicates polyoxometallates (POMs) ([SiW12O40]4−) were immobilized in a straightforward manner by electrostatic interactions on ammonium layers covalently grafted on silicon. This method does not require any POM modification synthetical steps. The presence of [SiW12O40]4− on the surface is demonstrated by X-ray Photoelectron Spectroscopy from a specific modification of the tungsten 4f7/2 signal. Moreover the surface coverage of [SiW12O40]4− has been improved by 35% upon changing the nature of the anchoring ammonium groups from protonated to methylated amino groups. The organic–inorganic composite films have also been characterized by cyclic voltammetry showing that POMs have a specific behavior on silicon surfaces. In addition the use of a polyallylamine capping layer proved to stabilize efficiently the POM electrochemical response. [Copyright &y& Elsevier]
- Published
- 2011
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