Highly Stable and Sensitive Gas Sensor Based on Single-Walled Carbon Nanotubes Protected by Metal-Oxide Coating Layer

摘要

We fabricated a highly stable and sensitive gas sensor based on single-walled carbon nanotubes (SWNTs) protected by metal-oxide coating layer. SWNTs were deliberately decorated with 2-5 nm of oxygen-deficient SiO_x and AlO_x by pulsed laser deposition, followed by annealing under Ar/H_2 ambient. Surpassing the as-grown SWNTs, the metal-oxide coated SWNTs showed an excellent sensing stability with a variation of sensor response less than 7-8%. The obtained sensitivity to NO_2 was also improved. Moreover, the relationship between NO_2 concentration and sensor response can be described by the Frumkin-Temkin isotherm.