Superior selectivity and enhanced response characteristics of palladium sensitized vanadium pentoxide nanorods for detection of nitrogen dioxide gas

Vanadium pentoxide (V2O5) nanorods have been deposited onto the glass substrates by spraying 75ml of 30mM vanadium trichloride (VCl3) solution at optimized substrate temperature of 400 degrees C. The XRD study confirms the formation of orthorhombic crystal structure of V2O5 nanorods. The FE-SEM micrograph shows the nanorods-like morphology of V2O5. The presence of palladium (Pd) in the Pd-sensitized V2O5 nanorods is confirmed using EDAX study. The gas sensing measurements show that the Pd-sensitized V2O5 sensing material is an outstanding candidate for nitrogen dioxide (NO2) gas detection. Obtained results demonstrate that the Pd-sensitized V2O5 nanorods show the superior selectivity for NO2 gas in comparison with other gases such as NH3, H2S, CO, CO2 and SO2 at an operating temperature of 200 degrees C. It shows the 75% response for 100ppm NO2 gas concentration with response and recovery times of 22s and 126s, respectively. Finally, the gas sensing mechanism based on chemisorption process is proposed to illustrate how Pd nanoparticles affect the gas sensing characteristics (response and response-recovery times). (C) 2017 Elsevier Inc. All rights reserved.