Gas sensing properties of individual composite nanostructures TiO2-x/MWCNT and SnOx/MWCNT measured by scanning probe microscopy

Abstract

Abstract The gas sensitivity properties of individual composite nanostructures based on multi-walled carbon nanotubes (MWCNT), functionalized by argon ions and coated with tin and titanium oxides, were investigated by the methods of scanning probe microscopy. The Fermi level shift and the change in longitudinal conductance of nanostructure upon absorption of ammonia and nitrogen dioxide are determined. It is shown that the change in conductance of the composite nanostructures correlates with the Fermi level shift under gases exposure as a result of charge carrier concentration changing in the metal oxide surface layers upon adsorption of gas molecules.