Preparation of Nanosize Tin Oxide Particles from Water-in-Oil Microemulsions

Nanoparticles of tin oxide (SnO2) have been prepared from water-in-oil microemulsions consisting of water, AOT (surfactant), andn-heptane (oil). Precursor hydroxides were precipitated in the aqueous cores of water-in-oil microemulsions and then calcined at 600°C for 2 h to form tin oxide powder. The formation of phase pure tin oxide was confirmed by means of X-ray diffraction analysis. The tin oxide powder was found to be less than 40 nm in particle diameter and to have a higher specific surface area, about 73 m2/g, when compared with tin oxide powder prepared through the conventional precipitation method (19 m2/g).