Premium
Raman spectroscopy of hydrotalcites with sulphate, molybdate and chromate in the interlayer
Author(s) -
Frost Ray L.,
Musumeci Anthony W.,
Martens Wayde N.,
Adebajo Moses O.,
Bouzaid Jocelyn
Publication year - 2005
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1385
Subject(s) - chromate conversion coating , hydrotalcite , raman spectroscopy , molybdate , chemistry , inorganic chemistry , polymerization , organic chemistry , catalysis , chromium , polymer , physics , optics
Raman microscopy has been used to characterize the interlayer anions in synthesized hydrotalcites of formula Mg 6 Al 2 (OH) 16 (XO 4 )·4H 2 O, where X is S, Mo or Cr. The Raman spectrum shows that both the chromate and molybdate anions are not polymerized in the hydrotalcite interlayer. This lack of polymerization is attributed to the effect of pH during synthesis. A model of bonding is proposed for the interlayer anions based upon the observation of two symmetric stretching modes and symmetry lowering of the chromate, molybdate and sulphate anions. Two types of anions are present, hydrated and hydroxyl surface‐bonded. Copyright © 2005 John Wiley & Sons, Ltd.