Please use this identifier to cite or link to this item:
Title: Ionic interactions in crystallite growth of CoMgAl-hydrotalcite-like compounds
Authors: Xu, Z.P. 
Zeng, H.C. 
Issue Date: 2001
Citation: Xu, Z.P., Zeng, H.C. (2001). Ionic interactions in crystallite growth of CoMgAl-hydrotalcite-like compounds. Chemistry of Materials 13 (12) : 4555-4563. ScholarBank@NUS Repository.
Abstract: With XRD, FTIR, CHN, ICP, and DTA/TGA techniques, ionic interactions in the forms of cation replacement/incorporation in basal layers and anion exchange/insertion in the interlayer space have been investigated. The crystallite size is increased significantly, whereas basal spacing is reduced when Co2+ cations or both Co2+ and Co3+ in CoIICoIII-NO3hydrotalcite-like compound (CoIICoIII-NO3-HT) are replaced with Al3+ or Mg2+ and Al3+. IR vibrational modes of hydroxyl groups and intercalated anions have been utilized in identifying exchanged interlayer species, and thermal events revealed by DTA/TGA have been correlated in verifying compositional changes and ionic interactions. In exchange experiments of CoIICoIII-NO3-HT, aluminum is not only incorporated into the basal layers but is also inserted into the interlayer space (in the form of H2AlO3 -), which causes an increase in planar growth of basal layers (to about 3 times) and a similar increase (to 2-3 times) in the basal layer stacking along the c-axis. Other experiments for CoIIAl-NO3-HT and MgAl-NO3-HT also indicate similar increases in the planar growth (to 2-3 times) when nitrate anions are replaced by aluminate anions, although the extent of increase in layer number in the c-axis is not as high. It appears that stronger cation-to-anion attraction promotes the inter-basal-layer stacking in the c-axis, while smaller anion-to-anion lateral repulsion is beneficial to the intra-basal-layer growth; these can be practically achieved by incorporation of more trivalent cations and/or replacement of low-charged anions with higher charged ones.
Source Title: Chemistry of Materials
ISSN: 08974756
DOI: 10.1021/cm010222b
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Apr 17, 2021


checked on Apr 9, 2021

Page view(s)

checked on Apr 11, 2021

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.