Room temperature methane detection using palladium loaded single-walled carbon nanotube sensors

Single-walled carbon nanotubes (SWNTs) loaded with palladium (Pd) nanoparticles are used for detection of methane ranging from 6 to 100 ppm in air at room temperature. The Pd-SWNT nanosensors show advantages over conventional catalytic beads and metal oxide sensors for methane detection in terms of reduced size and power consumption by a factor of 100 and sensitivity by a factor of 10. A charge transfer sensing mechanism in which Pd attracts electrons from SWNTs to form a weakly bound complex Pddelta+(CH4)(delta-) is discussed. In addition, the elevated temperature and ultraviolet light effects on the sensor characteristics are also studied. (C) 2004 Published by Elsevier B.V.