Influence of morphology and structure geometry on NO₂ gas-sensing characteristics of SnO₂ nanostructures synthesized via a thermal evaporation method

• Published in: Sensors and actuators. B, Chemical Vol. 153; no. 1; pp. 11 - 16
• Main Authors: Shaalan, N.M, Yamazaki, T, Kikuta, T
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.03.2011
• Subjects: Evaporation; Nanoparticles; Nanostructure; Nanowires; Nitrogen dioxide; Sensors; Tin dioxide; Tin oxides
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2010.09.070

SnO₂ microwires, nanowires and rice-shaped nanoparticles were synthesized by a thermal evaporation method. The diameters of microwire and nanowire were 2μm and 50–100nm, respectively, with approximately the same length (∼20μm). The size of nanoparticles was about 100nm. It was confirmed that the as-synthesized products have SnO₂ crystalline rutile structure. The sensing ability of SnO₂ particle and wire-like structure configured as gas sensors was measured. A comparison between the particle and wire-like structure sensors revealed that the latter have numerous advantages in terms of reliability and high sensitivity. Although its high surface-to-volume ratio, the nanoparticle sensor exhibited the lowest sensitivity. The high surface-to-volume ratio and low density of grain boundaries is the best way to improve the sensitivity of SnO₂ gas sensors, as in case of nanowire sensor which exhibited a dramatic improvement in sensitivity to NO₂ gas.