title: Hydrothermal synthesis and electrochromic properties of potassium tungsten oxide nanorods.
abstract: Hexagonal K2W4O13 nanorods have been synthesized by hydrothermal treatment of the WO3 x H2O precipitate at 180 degrees C in the presence of K2SO4. The K2W4O13 nanorod single crystals of approximately 12 nm in diameter and tens to few hundreds nm long with the principal axis along the (001) direction were obtained when hydrothermal treatment was conducted in the presence of sufficient amount of K2SO4 while shorter nanorods with the same preferred orientation were obtained when less amount of K2SO4 was employed. On the other hand, square platelets of approximately 100 nm wide were obtained when prepared in the absence of the K2SO4. The important role of K2SO4 on morphological control of the hydrothermal products was explained based on selective adsorption of the sulfate ions on the crystal planes parallel to the (001) direction retarding the growth of these faces. The nanorod film showed satisfactory electrochromic property and can be used as a promising material in electrochromic application.
authors.affiliation: National Metal and Materials Technology Center 114 Thailand Science Park, Klong Luang, Pathumthani, 12120, Thailand.
authors.forename: Ramida
authors.initials: R
authors.lastname: Rattanakam
authors.forename: Sitthisuntorn
authors.initials: S
authors.lastname: Supothina