Fabrication and characterization of SnO₂ nanospheres for hydrogen detection

Abstract

This article demonstrates a novel chemical vapor deposition strategy of tin oxide (SnO 2) by vapor phase material reaction at room temperature and presents the applications to hydrogen detection using this material. Tin chloride anhydrate was used as the precursor, and it reacted with NH 3 to form Sn(OH) 4 nanospheres. The samples with Sn(OH) 4 nanospheres were subject to drying up at 80°C, and then they transformed to polycrystalline SnO 2 nanospheres. The X-ray diffraction measurement was carried out to investigate the structural properties of the SnO 2 films annealed at various temperatures. The morphology of the samples was investigated by field-emission scanning electron microscopy. Micropellistor was fabricated based on the SnO 2 catalyst for hydrogen detection. Compared with the traditional method to make SnO 2 sensing material (hydrolysis of SnCl 4 Á5H 2 O in basic solutions), the SnO 2 nanospheres prepared by this method have a higher relative sensitivity and a good linearity for the concentration of H 2 ranging from 0% v/v to 4% v/v. A short response time about 6 s was achieved.