Synthesis, Characterization and Electrical Conductivity of High Porous Tin Oxide Nanocrystallites for Ethanol Sensing

• Published in: Materials today : proceedings Vol. 4; no. 11; pp. 12094 - 12102
• Main Authors: Rajeeva, M.P., Naveen, C.S., Lamani, Ashok R., Jayanna, H.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2017
• Subjects: Combustion synthesis; Ethanol sensor; Nanoparticles; Porous material; Thick film; Tin oxide; Nanoparticles; Combustion synthesis; Thick film; Porous material; Ethanol sensor; Tin oxide
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2017.09.136

Tin oxide nanomaterials have been synthesized using gel combustion method by varying the oxidizer (conc. HNO3) and keeping fuel (C6H8O7) as a constant. The prepared samples were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Analysis X-ray Spectroscopy (EDAX) and UV-visible spectroscopy. In this work, the effects of crystallite size and porosity on electrical and ethanol sensing properties of SnO2 thick films assembled by nanocrystals were investigated. When the oxidizer increased from 0 to 6.2 moles the crystallite size decreased from 31 to 12nm whereas the porosity gradually increased as in the SEM images. Interestingly, it was found that their gas sensing properties to ethanol vapour were determined by considering crystallite size and porosity. The gas response increased firstly (≤ 6.2 moles) and then (> 6.2 moles) decreased with increasing crystallite size and decreasing porosity. The sensor sample prepared by using 6.2 moles of HNO3 dominated sensing performance about 95% sensitivity for 2.5VPC of ethanol by influencing the surface reaction activity. This work could provide an understanding for nanostructure of the porous gas sensing metal oxide materials.