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

Vapor sensors are easily fabricated onto alumina substrates using foils of silver-decorated nitrogen-doped multiwalled carbon nanotubes (cnx-mwnts-ag) as active sensing material. the vapor sensors are tested using carbon disulfide,acetone,ethanol,and chloroform vapors. the cnx-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 cnx-mwnts exhibit a better response and sensitivity when compared with pristine cnx-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. © 2016 eduardo gracia-espino et al.