Hierarchical SnO2 nanostructures for potential VOC sensor

Detection of volatile organic compounds (VOCs) is rapidly becoming a necessity as they have significant percentage in the indoor air pollution. Therefore, use of highly sensitive, small and portable VOC sensors ranges from households, offices to large industries. This paper deals with the use of a highly responsive semiconductor, i.e. SnO2, in VOC sensors. A hitherto unreported strategy of using hollow cage-frame-type nanostructures is proposed. These hollow particles supersede the response characteristics of solid or even the porous nanostructures, which are mostly used till date. VOCs such as: ethanol, methanol, acetone, toluene and formaldehyde can be easily detected using SnO2 hollow structures as the chemically active component of the sensor. The fabricated sensors exhibit high selectivity for each VOCs, at different operating temperature. The sensing mechanism of hollow nanostructures is also described in detail. The work can initiate significant activity on VOC sensing using hollow structures, which has remained ignored till now.