Highly Sensitive, Room-Temperature Gas Sensors Prepared from Cellulose Derivative Assisted Dispersions of Single-Wall Carbon Nanotubes

We have developed highly sensitive gas sensors based on single-wall carbon nanotube (SWNT) networks prepared from aqueous hydroxypropylcellulose-assisted dispersions. Gas responses were monitored at room temperature for different concentrations of NO2. The stable baseline and its recovery (after NO2 exposure) were achieved by ultraviolet (UV)-induced photodesorption, for which a compact and low-power UV light emitting diode can be used as a light source. The sensors are capable of detecting 25 ppb or lower concentrations of NO2 and 5 ppm ammonia, and show almost no baseline drift after multiple NO2 exposures. The simple and low-cost fabrication process, reproducible performance and room-temperature operation bode well for industrial mass production and broad uses.