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Modification of Nanocrystalline TiO 2 with Phosphonate‐ and Bis(phosphonate)‐Bearing Macrocyclic Complexes: Sorption and Stability Studies
Author(s) -
Řehoř Ivan,
Kubíček Vojtěch,
Kotek Jan,
Hermann Petr,
Száková Jiřina,
Lukeš Ivan
Publication year - 2011
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201001100
Subject(s) - phosphonate , chemistry , sorption , desorption , adsorption , anatase , inorganic chemistry , nanoparticle , surface modification , colloid , phosphate , polymer chemistry , organic chemistry , chemical engineering , catalysis , photocatalysis , engineering
The first systematic study of chemical adsorption/desorption of phosphonic acid and geminal bis(phosphonic acid) on/from the surface of anatase nanoparticles is reported. Stable TiO 2 colloidal nanodispersions were used in the study. The colloidal stability is preserved upon nanoparticle modification. A macrocyclic lanthanide(III) complex, attached through a phosphonic/bis(phosphonic) group to the TiO 2 surface allowed precise quantification of sorption parameters by means of inductively coupled plasma atomic emission spectroscopy (ICP‐AES). Results show different behavior of phosphonate and bis(phosphonate) groups. For phosphonate, a monomolecular layer formation was observed, and the desorption rate depends on the sorption conditions. It is probably caused by different phosphonate binding modes on the surface. Excess amounts of phosphate in the washing media accelerates the desorption rate of the phosphonate. The bis(phosphonate) is adsorbed on the surface in large quantities forming multilayers that resist desorption even in the presence of phosphate ions and, thus, the bis(phosphonate) moiety is a suitable group for anchoring other molecules on the TiO 2 particle surface.