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.