Investigation of Ag-Doping in Kinetically Sprayed SnO2 Composite Film and Its Application to Gas Sensor

• Published in: International journal of precision engineering and manufacturing Vol. 20; no. 11; pp. 1989 - 1996
• Main Authors: Choi, Dahyun, Lee, Hee Chul, Kim, Hyojun, Kim, Hyeong-Gwan, Ji, Choon Woo, Son, Minhee, Lee, Caroline Sunyong
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society for Precision Engineering 01-11-2019; Springer Nature B.V
• Subjects: Carbon monoxide; Doping; Electron transport; Engineering; Gas sensors; Industrial and Production Engineering; Materials Science; Nanoparticles; Nozzles; Regular Paper; Sensors; Silver; Spraying; Substrates; Tin dioxide; Gas sensor; In situ deposition; SnO; Silver nanoparticles; Kinetic spraying
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-019-00208-8

We have developed a facile method to fabricate Ag-doped SnO
2
composite film prepared via one-step kinetic spraying process. We used supersonic/subsonic nozzles to accelerate powders to their maximum kinetic energies when bombarding the substrates; no post-treatment was required. Under optimized conditions, sensors fabricated from SnO
2
-based films with and without Ag nanoparticles (NPs) were smooth and about 7 µm in thickness. To improve CO-sensing performance, Ag NPs (to less than 1 wt%) were added to SnO
2
films. The sensor response to CO of the film with 1 wt% Ag was up to 20-fold better than that of the Ag-free film, even a low CO concentration of 500 ppm. We thus confirmed that addition of a small amount of Ag NPs to a SnO
2
film increased electron transport and improved catalysis of oxygen ionization on the film surface. Therefore, we have developed a facile method of Ag-doping in composite gas sensor and this crack-free composite gas sensor was found to be highly sensitive to CO gas.