Structural and sensing properties of a novel Fe/Fe2O3/ polyoxocarbosilane core shell nanocomposite powder prepared by laser pyrolysis

This paper reports about the synthesis and characterization of a novel Fe/Fe2O3/polyoxocarbosilane core shell nanocomposite as a material for gassensing applications. The nanocomposites (Fe-based nano cores enveloped with polymeric polyoxocarbosilane shells) were prepared by the IR laser co-pyrolysis of iron pentacarbonyl and hexamethyldisiloxane. The iron-based cores become superficially oxidized in atmosphere. The morphologies, chemical content and thermal behavior were studied by different analytical techniques. The sensing properties of the polymerpoor nanocomposite thick films were tested by measuring the variation of the electrical resistance in presence of CO and CH4, at a working temperature of 450 C. Preliminary results indicate that for CO toxic gas, an n–p transitional character of the semiconducting iron oxide appears in humid relatively to dry air.