A Solution-Phase, Precursor Route to Polycrystalline SnO₂ Nanowires That Can Be Used for Gas Sensing under Ambient Conditions

Abstract

This paper describes a solution-based, precursor method for the facile synthesis of uniform nanowires containing rutile SnO2 nanocrystallites. In a typical procedure, nanowires of approximately 50 nm in diameters and up to 30 mum in length were obtained as a white precipitate by refluxing SnC2O4.2H2O and poly(vinylpyrrolidone) in ethylene glycol. Structural analyses by XRD, FT-IR, and TGA indicate that these highly anisotropic nanostructures were formed in an isotropic medium through the aggregation of chainlike precursors that were, in turn, formed via polyol-mediated oligomerization. These nanowires could be further converted to polycrystalline SnO2 by calcination in air at 500 degrees C. The resultant nanowires of SnO2 were highly porous and could be used for gas sensing with improved sensitivity and reversibility under ambient conditions. We have also demonstrated that this new approach could be extended to generate polycrystalline nanowires of other metal oxides such as In2O3 and anatase TiO2.

Use of nanotechnology for clean and safer future environment

“…Photochemical SnO 2 nanoribbon sensors have been fabricated for detecting low concentrations of NO 2 at room temperature under UV light [18]. Polycrystalline SnO 2 nanowire sensors were also developed for sensing ethanol, CO, and H 2 gas [19]. SnO 2 nanohole array sensors have exhibited a reversible response to H 2 [20].…”

Synthesis and Applications of One-Dimensional Porous Nanowire Arrays: A Review

“…Wang et al 71 and Zhang et al 108 fabricated a kind of highly sensitive porous SnO 2 nanowires by solution-phase precursor route and electrospinningetching route, respectively. They found that these porous SnO 2 nanowire sensors showed high sensitivity and reversibility to some gases (CO, H 2 , etc.)…”

Synthesis and characterization of SnO2 nano particles for carbon absorbing applications

“…In recent days, nanowire and nanotube based materials have been well demonstrated as building blocks for nano circuits, nano systems and nano-optoelectronics. For the same reasons, researchers focuses their interest on one-dimensional nano structured SnO 2 materials [10][11][12][13] . In quantum size effect, when the particle size of a semiconductor is compared to the Bohr radius 14 , the ratio of surface atomsto those with the interior enhances the surface properties of the materials.…”