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Effect of Halide Contaminant Ions in the Hydrothermal Treatment of Amorphous Titania on the Phase Change from Anatase to Rutile During Calcination
Author(s) -
Ovenstone James,
Chan KinChau
Publication year - 2001
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 - 10.1002/1099-0682(200105)2001:5<1339::aid-ejic1339>3.0.co;2-h
Subject(s) - anatase , rutile , calcination , chemistry , inorganic chemistry , crystallization , nucleation , hydrothermal circulation , amorphous solid , chemical engineering , phase (matter) , adsorption , mineralogy , photocatalysis , crystallography , organic chemistry , catalysis , engineering
Hydrothermal treatment in salt solutions has been used to crystallise and stabilise the anatase phase of titania. Halide contaminants have been shown to accelerate crystallisation of anatase when compared to reactions in pure water, but as anion size increases, the crystallisation improvement is less. The crystallised anatase has then been calcined to form rutile. The impurity ions appear to adsorb to the titania surface and have been shown to have a strong influence on the anatase/rutile transition, reducing the rutile formation during calcination due to the steric hindrance of the rutile nucleation sites on the titania surface. The adsorption sites for the anions affecting anatase crystallisation and rutile formation are different.