Synthesis and NO2 sensing characteristics of Mg-functionalized VO2(M) Nanorods

Abstract

Herein, we report the synthesis , characterization, and potential ${\mathrm{NO}}_2$ gas sensing application of pristine and Mg-doped ${\mathrm{VO}}_2$(M) nanorods sensors. The gas sensing properties of both sensors were tested for various analytes, i.e., CO, ${\mathrm{CH}}_4$, $H_2$S, ${\mathrm{NO}}_2$, ${\mathrm{SO}}_2$ while varying operating temperatures. The sensors demonstrated substantial sensing performance at working temperature of about $120°C$, where ${\mathrm{VO}}_2$-Mg outperformed the pristine sensor with a response value of about 59.3%. At ambient temperature ($\sim 25°C$), the response values for pristine and ${\mathrm{VO}}_2$-Mg were 3.29% and 6.35%, respectively. The Mg-dopant’s catalytic activity alters the electrical characteristics and adsorbed oxygen species on the sensor surface, leading to improved sensing performance. ${\mathrm{VO}}_2$(M)-based sensor‘s sensing mechanism fits the Freundlich isotherm model, thus making the sensors suitable for detecting ${\mathrm{NO}}_2$ at high and ambient temperatures.