Investigation on CH4 sensing characteristics of hierarchical V2O5 nanoflowers operated at relatively low temperature using chemiresistive approach

• Published in: Analytica chimica acta Vol. 1106; pp. 148 - 160
• Main Authors: Mounasamy, Veena, Mani, Ganesh Kumar, Ponnusamy, Dhivya, Tsuchiya, Kazuyoshi, Reshma, P.R., Prasad, Arun K., Madanagurusamy, Sridharan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-04-2020
• Subjects: CH4; Gas sensor; Hierarchical nanostructures; Sputtering; Thin film; V2O5; Gas sensor; Hierarchical nanostructures; V2O5; Sputtering; CH4; Thin film
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2020.01.060

Methane (CH4) gas, the second most potent greenhouse gas share a substantial role in contributing to the global warming and it is a necessary pre-requisite to detect the release of CH4 into the environment at its early stage to combat climate change. In that front, this work is focussed to develop an effective CH4 gas sensor using vanadium pentoxide (V2O5) thin films that works at an operating temperature of ∼100 °C. To understand the effect of sputtering power towards the structural characteristics of V2O5 films, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) analysis were performed from which the orthorhombic polycrystalline structure of V2O5 thin films was confirmed with varied texture co-efficient. Further, the surface elemental studies using X-ray photoelectron spectroscopy (XPS) confirmed the prominence of V+5 oxidation state from the binding energy of V2p3/2 and O1s peak. The effect of sputtering power on the growth of different nanostructures were observed using field-emission scanning electron microscopy (FE-SEM). The critical role of adsorption and desorption kinetics of the deposited nanostructures were explained through first order kinetics based on Elovich model and the phase stability of different nanostructures were evaluated using Raman spectral analysis. This work achieved the sensor response of about ∼8% towards CH4 at an operating temperature of 100 °C towards 50 ppm concentration.
Schematic of V2O5nanoflower sensing mechanism towards CH4gasMethane (CH4) gas sensing characteristics and sorption kinetics of hierarchical vanadium pentoxide (V2O5) thin film. [Display omitted]
•Polycrystalline orthorhombic V2O5 with hierarchical nanostructures using dc sputtering.•Stable V+5 stoichiometry with varied preferential orientation for different nanostructures.•Sequential sensing studies towards CH4 achieving sensitivity at relatively low operating temperature of 100 °C towards 50 ppm.•Adsorption and Desorption kinetics elucidation using Elovich plot.