Novel hybrid materials for gas sensing applications made of metal-decorated MWCNTs dispersed on nano-particle metal oxides

Novel hybrid gas-sensitive materials were fabricated by means of metal-decorated multiwall carbon nanotubes (MWCNT) dispersed on nano-particle metal oxides. The MWCNT were initially functionalized in an oxygen plasma for improving their dispersion and surface reactivity, and then they were decorated with metal nano-clusters by thermally evaporating gold or silver on the MWCNT. Active layers for gas sensing applications were obtained by adding a small amount of metal-decorated MWCNT to two different types of metal oxides (SnO2 and WO3). The hybrid materials have been analyzed by means of XPS, TEM and SEM. The gas sensing potential of the fabricated hybrid materials has been tested upon exposure to different hazardous species, specifically NO2, CO, C6H6 and NH3, at low operating temperature.