Abstract
The unique structure of carbon nanotubes endows them with fantastic physical and chemical characteristics. Carbon nanotubes have been widely studied due to their potential applications in many fields including conductive and high-strength composites, energy storage and energy conversion devices, sensors, field emission displays and radiation sources, hydrogen storage media, and nanometer-sized semiconductor devices, probes, and quantum wires. Some of these applications have been realized in products, while others show great potentials. The development of carbon nanotubes-based sensors has attracted intensive interest in the last several years because of their excellent sensing properties such as high selectivity and prompt response. Carbon nanotube-based gas sensors are summarized in this paper. Sensors based on single-walled, multiwalled, and well-aligned carbon nanotubes arrays are introduced. Modification of carbon nanotubes with functional groups, metals, oxides, polymers, or doping carbon nanotubes with other elements to enhance the response and selectivity of the sensors is also discussed.
Highlights
Carbon nanotubes (CNTs) are a group of one-dimensional nanoscale materials composed of carbon atoms with fullerene structure, in which each carbon atom is sp2 hybrid and every carbon atom is covalently bonded to another three adjacent carbon atoms
Much effort has to be done before the practical application of CNTs-based gas sensors
Gas sensors are required to be with high selectivity, low operating temperature, quick response and recovery
Summary
Carbon nanotubes (CNTs) are a group of one-dimensional nanoscale materials composed of carbon atoms with fullerene structure, in which each carbon atom is sp hybrid and every carbon atom is covalently bonded to another three adjacent carbon atoms. MWCNT comprise of several layers of graphene cylinders that are concentrically nested like rings of a tree trunk, with an interlayer distance close to that of graphite (0.34 nm). Both MWCNTs and SWCNTs have diameters in the range between fractions of nanometers and tens of nanometers and length up to several centimeters with both their ends normally capped by fullerene-like structures [1]. Most of the CNT sensors are based on FET devices with a semiconductive single nanotube (Figure 1(a)) or nanotube networks (Figure 1(b)) as the active sensing elements, and the conductivity of the CNTs was monitored when the sensors were exposed to various atmospheres
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
