H2S gas sensing behavior of 2-D V2O5 nanowire network structure

In this study, a nanowire network-based V2O5 nanostructure, designed as the active surface in H2S gas sensors, was produced using an environmentally friendly method known as hydrothermal synthesis. The morphological, structural, and electrical properties of the produced nanostructure were characterized using various measurement techniques. XRD, SEM, and EDX analyses confirmed that the nanostructure was in a pure monoclinic phase, had a two-dimensional (2-D) nanowire network morphology, and was deposited stoichiometrically. From UV–Vis analysis, the energy band gap value of the nanostructure was calculated to be 2.65 eV. In gas sensing measurements conducted between 27 °C and 102 °C, the optimal operating temperature of the fabricated sensor was determined to be 42 °C. At this temperature, which is close to room temperature, the sensor exhibited a high sensitivity of 21.16 % for 50 ppm H2S gas, along with good selectivity, stable repeatability, and baseline stability. Moreover, for 2 ppm H2S gas, the response and recovery times were 39 s and 58 s, respectively. A comprehensive electrical analysis of the sensor was carried out through impedance spectroscopy measurements over a wide temperature range. Our findings indicate that the 2-D V2O5 nanowire network structure (NNS) results in several notable effects, including low operating temperature, high selectivity, and stability for H2S gas, demonstrating considerable potential for industrial applications. © 2024 Elsevier Ltd and Techna Group S.r.l.