Hydrogen sensors based on carbon nanotubes thin films

Single-walled carbon nanotubes (SWNTs) produced by arc-discharge have been researched as resistive gas sensors for H, detection. Raw as well as modified single-walled carbon nanotubes were utilised as sensor material. Two types of modification treatments were carried out on the as grown SWNT material; chemical functionalization with palladium and doping with palladium by sputtering. CNTs were deposited on alumina substrates by airbrush. Two different alumina substrates (with and without heater element) were used to obtain the sensor devices. Conductance measurements were carried out in a N-2 constant flow for H-2 detection. The results demonstrate that the CNTs are p-type semiconductor materials, increasing their resistance with reducing gases. SWNTs functionalized with Pd show the best response when exposed to H-2 at room temperature. (C) 2004 Published by Elsevier B.V.