Highly sensitive detection of carbon monoxide at room temperature using platinum-decorated single-walled carbon nanotubes

We demonstrated highly sensitive detection of carbon monoxide (CO) down to 1 ppm at room temperature using platinum-decorated single-walled carbon nanotubes (Pt-SWNTs). The obtained sensitivity to CO was 3-4 orders higher than the values reported for functionalized SWNTs, and was achieved by the controlled deposition of Pt nanoparticles on SWNTs. For 1-10 ppm of CO, the sensor response linearly increased with CO concentration, affording the quantitative detection of CO. in a low-concentration range. Furthermore, Pt-SWNTs exhibited detection selectivity to CO against H(2). The sensing mechanism was attributed to electron donation to the SWNTs as a result of CO oxidation on the Pt catalyst surface. (C) 2008 The Japan Society of Applied Physics.