title: One dimensional spindle titanium oxide nanocrystals.
abstract: Anatase TiO2 nanocrystals of 10 nm were formed in aqueous solutions at 90 degrees C for 1 day. The solutions contained ammonium hexafluorotitanate (5 mM) and boric acid (15 mM). The nanocrystals connected each other to form particles of about 100-500 nm. X-ray diffraction, Raman and FT-IR analysis revealed characteristics of the nanocrystals. They had BET surface area of 68 m2/g. Furthermore, morphology was controlled to one dimensional spindle shape by change of supersaturation degree. The spindle nanocrystals of 30 nm in width and 100 nm in length were formed in low concentration solutions. They contained hexafluorotitanate of 0.5 mM and boric acid of 0.15 mM. The spindle nanocrystals had higher crystallinity compared to the above nanocrystals. BET surface area reached 88 m2/g. One dimensional structure was realized by anisotropic crystal growth along c-axis. Low supersaturation degree decreased growth speed and brought out anisotropic crystal growth.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Masuda
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kato