Cadmium metavanadate mixed oxide nanorods for the chemiresistive detection of methane molecules

• Published in: New journal of chemistry 2020-08, Vol.44 (29), p.12473-12485
• Main Authors: Mounasamy, Veena, Mani, Ganesh Kumar, Ponnusamy, Dhivya, Tsuchiya, Kazuyoshi, Reshma, P. R, Prasad, Arun K, Madanagurusamy, Sridharan
• Format: Article
• Language: English
• Subjects: Cadmium; Detection; Gas sensors; Methane; Nanorods; Operating temperature; Photoelectrons; Polycrystals; Thin films; Transition metal oxides; Vanadium pentoxide; X ray photoelectron spectroscopy
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d0nj02690e

Mixed transition metal oxides (MTMOs) have recently been explored as building blocks for gas sensing applications due to their enhanced sensing characteristics. Here, we demonstrate the application of a co-sputtered V 2 O 5 -CdO thin film as a novel chemiresistive sensor for the detection of methane (CH 4 ) gas. From X-ray diffraction (XRD) studies, the mixed phase was identified as polycrystalline cadmium metavanadate (CdV 2 O 6 ), and from X-ray photoelectron spectroscopy (XPS) studies, the clear existence of V 5+ and Cd 2+ , corresponding to V 2 O 5 -CdO, was observed. The obtained mixed phase featured fused nanorod-like structure with ∼450 nm thickness. By monitoring the sequential sensing characteristics over various temperature (RT-150 °C) and concentration (25-500 ppm) range, the optimum operating temperature (100 °C) was identified. The polycrystalline V 2 O 5 -CdO sensor exhibited a response of ∼1.72% towards 25 ppm CH 4 at 100 °C. The use of evenly co-sputtered semiconductive (Cd 2+ and V 5+ ) nanorods will provide advanced routes towards the development of various devices based on MTMOs. An energy band diagram of the V 2 O 5 -CdO thin film and illustration of the methane (CH 4 ) gas sensing mechanism with band bending.