Preparation of water-dispersible TiO2 nanoparticles from titanium tetrachloride using urea hydrogen peroxide as an oxygen donorElectronic supplementary information (ESI) available. See DOI: 10.1039/c3ce41561a

• Main Authors: Watanabe, Naoko, Kaneko, Taichi, Uchimaru, Yuko, Yanagida, Sayaka, Yasumori, Atsuo, Sugahara, Yoshiyuki
• Format: Journal Article
• Language: English
• Published: 19.11.2013
• ISSN: 1466-8033
• DOI: 10.1039/c3ce41561a

TiO 2 nanoparticles were prepared from titanium tetrachloride (TiCl 4 ) in CH 2 Cl 2 at 80 °C for 30 h, 42 h and 70 h using urea hydrogen peroxide (UHP) as an oxygen donor with a TiCl 4  : UHP molar ratio of 1 : 2. The XRD patterns and Raman spectroscopy results showed that the products consisted of anatase TiO 2 . IR and solid-state 13 C NMR with cross polarization and magic angle spinning techniques revealed the presence of urea. TEM observation revealed that the products prepared by the reactions for 30 and 42 h consisted of water-dispersible spheroid nanoparticles with a long axis of ~5 nm, while an aggregation of nanoparticles was evident upon reaction for 70 h. Thermogravimetry, inductively-coupled plasma emission spectrometry and CHN analysis showed that the amount of urea increases in the following order: TiO 2 _42h, TiO 2 _70h, TiO 2 _30h. The photocatalytic activity of the products dispersible in water (TiO 2 _30h and TiO 2 _42h) was estimated based on the degradation behaviour of methylene blue, and TiO 2 _42h showed higher photocatalytic activity than TiO 2 _30h. It is proposed that TiCl 4 was directly oxidized by UHP to form anatase TiO 2 in the early stage of the process. Water-dispersible anatase TiO 2 nanoparticles were prepared from titanium tetrachloride (TiCl 4 ) in CH 2 Cl 2 at 80 °C using urea hydrogen peroxide (UHP) as an oxygen donor with a TiCl 4  : UHP molar ratio of 1 : 2, and the photocatalytic activities of the resulting TiO 2 nanoparticles were examined.