XAFS study on the local atomic structures of cerium-oxide nanoparticles with surface coatings Article

Wu, Z, Zhang, J, Chen, X et al. (2005). XAFS study on the local atomic structures of cerium-oxide nanoparticles with surface coatings . T115 802-806. 10.1238/Physica.Topical.115a00802



cited authors

  • Wu, Z; Zhang, J; Chen, X; Chen, Z; Sun, M; Wu, Z; Guo, L

fiu authors

abstract

  • Four kinds of cerium oxide nanoparticles coated, respectively, with Sodium bis(2-ethylhexyl) sulfosuccinate (AOT), cetyltrimethyl ammonium bromide (CTAB), poly vinyl pyrrolidone (PVP) and those (naked) without surface coating were prepared using chemical method. The particle sizes were identified to be 2-3 nm by using transmission electron microscope (TEM) and x-ray diffraction (XRD). Mixed valences of Ce3+ and Ce4+ were detected by x-ray absorption near-edge-structure (XANES) spectra. Extended x-ray absorption fine structure (EXAFS) spectra of Ce L3-edge were fitted with a core-shell model. The core parts are almost the same as bulk CeO2 with Ce 4+ characteristic, however their shell parts change with surface coatings. The local atomic structures at shell parts (surface) and the contents and thicknesses of the shell parts were evaluated. The averaged Ce-O bond lengths at surface are changed from 2.504 Å (AOT), 2.568 Å (PVP), 2.628 Å (CTAB) to 2.634 Å (naked). The contents of surface are changed from 49% (AOT), 15% (PVP), 19% (CTAB) to 15% (naked). The results demonstrate that surface coatings have different influences on the surfaces of cerium oxide nanoparticles. A detailed discussion is given in this paper. © Physica Scripta 2005.

publication date

  • December 1, 2005

Digital Object Identifier (DOI)

start page

  • 802

end page

  • 806

volume

  • T115