Gas sensors based on doped-CNT/SnO₂ composites for NO₂ detection at room temperature

For the first time nitrogen or boron doped carbon nanotubes were added into a SnO matrix to develop a new hybrid CNTs/SnO gas sensors. The hybrid sensor is utilised to detect low ppb concentrations of NO in air, by measuring resistance changes of thin CNTs/SnO films. The tests are performed at room temperature. For comparison, pure SnO and N or B-substituted CNT sensors are also examined. Comparative gas sensing results reveal that the CNTs/SnO hybrid sensors exhibit much higher response towards NO , at least by a factor of 10, and good baseline recovery properties at room temperature than the blank SnO and the N or B-substituted CNT sensors. This finding shows that doping SnO with low quantity of CNTs doped with heteroatoms can dramatically improve sensitivity.