LAUSR

In this study, high-density carbon nanotubes (CNTs) are grown on an oxidized Si substrate by thermal chemical vapor deposition (CVD). CNTs were synthesized by thermal CVD at 700 °C in a C2H2 atmosphere and used to fabricate a gas sensing-device. The average length and diameter of the CNTs were about ~ 4.52 μm and ~ 45 nm, respectively. Au nanoparticles were coated onto nanotube surfaces to a thickness of approximately 5 nm and the CNTs thus formed could be utilized to sense acetone vapor. In 800 ppm ammonia (NH3) vapor at room temperature, the adsorption of Au nanoparticles increased the sensitivities of the device to these species from 1.11, 1.54, 2.03, 2.44 and 2.74%, respectively.