High-Energy Faceted SnO2‑Coated TiO2 Nanobelt Heterostructure for Near-Ambient Temperature-Responsive Ethanol Sensor

• Published in: ACS applied materials & interfaces 2015-11, Vol.7 (44), p.24950-24956
• Main Authors: Chen, Guohui, Ji, Shaozheng, Li, Haidong, Kang, Xueliang, Chang, Sujie, Wang, Yana, Yu, Guangwei, Lu, Jianren, Claverie, Jerome, Sang, Yuanhua, Liu, Hong
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.5b08630

A SnO2 gas sensor was prepared by a two-step oxidation process whereby a Sn­(II) precursor was partially oxidized by a hydrothermal process and the resulting Sn3O4 nanoplates were thermally oxidized to yield SnO2 nanoplates. The SnO2 sensor was selective and responsive toward ethanol at a temperature as low as 43 °C. This low sensing temperature stems from the rapid charge transport within SnO2 and from the presence of high-energy (001) facets available for oxygen chemisorption. SnO2/TiO2 nanobelt heterostructures were fabricated by a similar two-step process in which TiO2 nanobelts acted as support for the epitaxial growth of intermediate Sn3O4. At temperatures ranging from 43 to 276 °C, the response of these branched nanobelts is more than double the response of SnO2 for ethanol detection. Our observations demonstrate the potential of low-cost SnO2-based sensors with controlled morphology and reactive facets for detecting gases around room temperature.