Evolution of Nanoscale SnO2 Grains, Flakes, and Plates into Versatile Particles and Films through Crystal Growth in Aqueous Solutions

• Published in: Crystal growth & design Vol. 5; no. 3; pp. 1079 - 1083
• Main Authors: Ohgi, Hirotoshi, Maeda, Takahiro, Hosono, Eiji, Fujihara, Shinobu, Imai, Hiroaki
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 01.05.2005
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Scanning electron microscopy; Inorganic compounds; Nucleation; Porous materials; Specific surface area; Binary compounds; XRD; Amorphous state; Experimental study; Tin oxides; Self-assembly; Hydrothermal synthesis; Aqueous solutions; Morphology; Crystal growth from solutions; Oxidation; Nanostructured materials; Nanocrystal
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg049644z

Hierarchically structured porous particles and films consisting of nanocrystalline SnO2 were spontaneously grown by gradual oxidation of tin(II) in a simple aqueous system at a low temperature. The nanoscale shape and macroscopically assembled architecture of SnO2 crystallites were totally controlled by preparation conditions for crystal growth. Spherical and prickly particles exhibiting a high specific surface area in the range of 120−230 m2/g were produced by organized growth of nanoscale SnO2 grains and flakes, respectively. Porous SnO2 films consisting of the nanograins and nanoflakes were directly grown on a glass substrate through heterogeneous nucleation promoted by addition of urea. Cellular aggregates and films composed of platy subunits were constructed in the solutions under an oxygen-deficient condition. Amorphous and monoxide phases contained in as-deposited particles and films were easily transformed into SnO2 crystals without deformation of the macroscopic architecture by subsequent hydrothermal treatment at 150 °C in water and calcination at 500 °C in air, respectively. The easy-to-handle nanocrystalline SnO2 with hierarchical and porous architectures would be utilized for various practical applications.