Fabrication of C-doped WO3 nanoamterial-based gas sensors for highly sensitive NO2 detection at room temperature

This paper firstly reports a method to fabricate C-doped tungsten oxide (WO3) nanomaterials using carbon nanotubes (CNTs) template and demonstrates its application to highly sensitive NO2 gas sensing at room temperature. The W-coating on the CNTs template is performed by a simple solution process, and the C-doped WO3 nanomaterials are synthesized through an annealing process while the CNTs are removed simultaneously. The synthesized C-doped WO3 has a shape like the CNTs, which indicates that the material has a large surface area favorable for sensitive gas detection. The fabricated sensor detected 6 ppm of NO2 at room temperature and returned perfectly to its original state. These sensing performance is comparable to the existing WO3-based NO2 sensors.