Metal-decorated multi-wall carbon nanotubes for low temperature gas sensing

We investigate the possibility of using, as a gas sensitive material, multi-walled carbon nanotubes (MWCNT) covered with gold or silver nanoclusters deposited by thermal evaporation. Metal-decorated MWCNT were dispersed in an organic vehicle, micro-deposited onto silicon micro-machined sensor substrates and subsequently annealed to remove the organic vehicle. The resulting sensors are shown to be sensitive to NO2 when operated at room temperature and significantly more selective than sensors based on MWCNT without metal nanoclusters attached to their surface.