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.