title: Surface passivation of CeO2 catalyst and its ultraviolet screening effect.
abstract: A new strategy was attempted to fabricate CeO2 nanoparticles using the surface fluorination technique to control the particle size and suppress the catalytic activity. The fluorinated CeO2 nanoparticles are fully characterized with XRD, XANES, UV-vis spectroscopy, HR-TEM, XPS along with the evaluation of photo and thermal catalytic activities. XRD patterns were not affected by surface fluorination. That is to say, the crystalline structure of CeO2 was not deteriorated upon fluorination. The TEM analysis showed that the fluorinated CeO2 nanoparticles with the primary particle size of 7 nm could be prepared. According to the X-ray absorption near edge structure (XANES) analysis, overall XANES spectrum was not changed upon fluorination, suggesting that the local structure of fluorinated CeO2 resembled that of the starting CeO2 nanoparticles. It was also revealed that both photo and thermal catalytic activities could be almost totally suppressed at the fluorination level of ca. 6.0 wt%. It is suggested that the selective surface fluorination with fluoride could lead to fluorinated CeO2 nanoparticles, which could be applied to new fields such as the cosmetics industries.
authors: Center for Intelligent Nano-Bio Materials (CINBM), Department of Bioinspired Science and Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 120-750, Korea.
authors: Joo-Hee
authors: JH
authors: Kang
authors: Yun-Hee
authors: YH
authors: Kim
authors: Seung-Min
authors: SM
authors: Paek
authors: Jin-Ho
authors: JH
authors: Choy