Comparative analysis of hydrogen sensing based on treated-TiO2 in thick film gas sensor

• Published in: Applied physics. A, Materials science & processing Vol. 128; no. 7
• Main Authors: Mohd Chachuli, Siti Amaniah, Hamidon, Mohd Nizar, Ertugrul, Mehmet, Mamat, Md. Shuhazlly, Coban, Omer, Shamsudin, N. H.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2022; Springer Nature B.V
• Subjects: Aluminum oxide; Anatase; Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Crystallites; Electrical resistivity; Gas sensors; Hydrogen; Machines; Manufacturing; Materials science; Nanotechnology; Nitrogen; Operating temperature; Optical and Electronic Materials; Pastes; Physics; Physics and Astronomy; Processes; Screen printing; Sensitivity; Sensors; Smell; Substrates; Surfaces and Interfaces; Thin Films; Titanium dioxide; Crystallite size; Organic binder; nanoparticles; TiO; Screen-printing; thick film gas sensor
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-022-05738-z

This paper compares two TiO 2 thick film gas sensors to the hydrogen at elevated operating temperatures. The first gas sensor was prepared by applying nitrogen treatment at 200 °C for 2 h to the TiO 2 powder before the TiO 2 paste was prepared. The second gas sensor was prepared using TiO 2 powder without purification to make the TiO 2 paste. Both TiO 2 pastes were prepared by mixing the sensing material with an organic binder. Both pastes were deposited on an alumina substrate using a screen-printing technique and annealed at 500 °C for 30 min under ambient air. FESEM and XRD characterizations were carried out to investigate the morphology and elemental composition. The results revealed that the TiO 2 thick film with nitrogen treatment produced slightly higher crystallinity and smaller crystallite sizes for the anatase and rutile phases than the TiO 2 thick film without nitrogen treatment. In terms of resistivity, the WTN gas sensor produced lower resistivity than the WON gas sensor for operating temperatures below 200 °C. The results were found that the WON gas sensor had higher sensitivity than the WTN gas sensor to various concentrations of hydrogen at the operating temperature of 150 °C, 200 °C, and 250 °C. Both gas sensors also produced similar optimum operating temperatures, which occurred at 200 °C. The sensitivity of the WON gas sensor was approximately 6.30, 8.39, 12.70, 15.92, and 19.87 optimum operating temperatures to 100 ppm, 300 ppm, 500 ppm, 700 ppm, and 1000 ppm of hydrogen, respectively. In addition, the WTN gas sensor has better stability characteristics for higher operating temperatures.