Fabrication of metal-oxide nanoparticles by the liquid phase deposition method in the heterogeneous system

For the development of the preparation method of size-controlled nanoparticles, we applied the liquid phase deposition (LPD) method to the reverse micelle (RM) reaction contained TritonX-100 and 1-hexanol. We prepared two kinds of metal oxide nanoparticle; TiO2 and SnO2. The average sizes of nanoparticles were 5.9 nm and 3.0 nm for TiO2 and SnO2, respectively. The size distribution was narrow, and crystallization of the particles was promoted by the nanoscale reaction field. The bandgap was calculated from UV-Vis spectra. The bandgap energy of SnO2 nanoparticles showed a larger value at 4.6 eV, whereas that of TiO2 nanoparticles showed a constant value at 3.2 eV. The quantum effect causes the variation of the bandgap, however, the effect depends on the kinds of the metal oxide.