Temperature Dependence of Sensors Based on Silver-Decorated Nitrogen-Doped Multiwalled Carbon Nanotubes

Abstract EN

Vapor sensors are easily fabricated onto alumina substrates using foils of silver-decorated nitrogen-doped multiwalled carbon nanotubes (CN X-MWNTs-Ag) as active sensing material.

The vapor sensors are tested using carbon disulfide, acetone, ethanol, and chloroform vapors.

The CN X-MWNTs are produced by chemical vapor deposition process and then decorated with 14 nm Ag nanoparticles (Ag-NPs).

The samples are characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction.

Our results demonstrate that Ag-decorated CN X-MWNTs exhibit a better response and sensitivity when compared with pristine CN X-MWNTs based sensors, making them promising candidates for air-pollutants environmental monitoring.

The temperature effect on the sensor performance is also studied; we found that the detection mechanism could be tuned from physisorption, at room temperature, to chemisorption at higher working temperature.

Finally, first-principles density functional calculations are carried out to understand the interactions between the systems involved in the sensors, finding good agreement between experimental results and the theoretical approach.