Progress in Carbon Nanotube Gas Sensor Research

Carbon nanotubes have become ideal candidates for fabricating nanosized gas sensors because of their excellent mechanical, electrical, physical, and chemical properties, one-dimensional nanostructure, high surface adsorption capability, superior conductive performance, and electronic ballistic transport characteristics. Recently, a great deal of effort has been devoted to the development of carbon nanotube-based gas sensors and rapid progress has been made. The results show that carbon nanotube gas sensors possess unique properties such as high sensitivity, fast response, small size, low energy consumption, and low operating temperature. In this review, we combine the great deal of work carried out by our group and try to summarize research progress in carbon nanotube-based gas sensors for environmental monitoring, medical diagnosis, and military and defense applications. The working mechanisms and manufacturing processes of these sensors are also presented and analyzed. Despite facing enormous challenges, owing to their excellent performance, sensors based on carbon nanotubes will be substitutes for commercially traditional gas sensors.