In:
Applied Organometallic Chemistry, Wiley, Vol. 18, No. 10 ( 2004-10), p. 553-560
Abstract:
We present X‐ray absorption spectroscopy (XAS) data, ultraviolet photoelectron spectra (He I ) and metastable impact electron spectra (MIES) of cobalt nanoparticles (typically 4 to 10 nm), prepared by Co 2 (CO) 8 thermolysis and pre‐stabilized by smooth oxidation. We find that the particles consist of a core–shell system with a dominantly f.c.c. core and a shell in which CoC and CoO coordination is likely to occur. This corresponds well to the results from electron spectroscopy, that stabilization occurs via formation of (CoCO x ) and (CoO) groups formed during the oxidation procedure and appears sensitive to the reaction conditions. Peptization of the pre‐stabilized particles with KorantinSH surrounds the particles with a dense organic shell, stable up to about 250°C. The carbonic acid molecules of the shell are oriented predominantly perpendicular to the surface of the particles, their carboxyl functional group linking the shell with the cobalt particles. This result is also supported by the XAS data, where it is observed that, during peptization, CoC coordination is partly replaced by CoO coordination. In order to arrive at these statements, auxiliary measurements on bare and gas‐exposed cobalt films, also reported here, were required. Copyright © 2004 John Wiley & Sons, Ltd.
Type of Medium:
Online Resource
ISSN:
0268-2605
,
1099-0739
Language:
English
Publisher:
Wiley
Publication Date:
2004
detail.hit.zdb_id:
1480791-9