Effects of niobium-loading on sulfur dioxide gas-sensing characteristics of hydrothermally prepared tungsten oxide thick film

• Main Authors: Viruntachar Kruefu, Anurat Wisitsoraat, Sukon Phanichphant
• Format: Journal
• Published: 2018
• Subjects: Agricultural and Biological Sciences
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84926443817&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/44768
• Institution: Chiang Mai University

© 2015 Viruntachar Kruefu et al. Nb-loaded hexagonal WO 3 nanorods with 0-1.0 wt% loading levels were successfully synthesized by a simple hydrothermal and impregnation process and characterized for SO 2 sensing. Nb-loaded WO 3 sensing films were produced by spin coating on alumina substrate with interdigitated gold electrodes and annealed at 450°C for 3 h in air. Structural characterization by X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis showed that spherical, oval, and rod-like Nb nanoparticles with 5-15 nm mean diameter were uniformly dispersed on hexagonal WO 3 nanorods with 50-250 nm diameter and 100 nm-5 μm length. It was found that the optimal Nb loading level of 0.5 wt% provides substantial enhancement of SO 2 response but the response became deteriorated at lower and higher loading levels. The 0.50 wt% Nb-loaded WO 3 nanorod sensing film exhibits the best SO 2 sensing performances with a high sensor response of 10 and a short response time of 6 seconds to 500 ppm of SO 2 at a relatively low optimal operating temperature of 250°C. Therefore, Nb loading is an effective mean to improve the SO 2 gas-sensing performances of hydrothermally prepared WO 3 nanorods.