Synthesis of brookite TiO2 nanoparticles by thermolysis of TiCl4 in strongly acidic aqueous media

• Published in: Journal of materials chemistry 2001, Vol.11 (4), p.1116-1121
• Main Authors: POTTIER, Agnès, CHANEAC, Corinne, TRONC, Elisabeth, MAZEROLLES, Léo, JOLIVET, Jean-Pierre
• Format: Article
• Language: English
• Subjects: Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Structure of solids and liquids; crystallography
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/b100435m

Nanometric particles of titania, brookite and rutile polymorphs were synthesised by thermolysis of TiCl4 in concentrated HCl solutions. The Cl:Ti molar ratio seems to be the key factor in determining the crystalline phases and their relative proportions, as well as the particle size, and a large proportion of brookite can be obtained under specific conditions. The complex, Ti(OH)2(Cl)2(OH2)2, appears to be the precursor of the brookite phase. The presence of chloride ions is also necessary to stabilise brookite in suspension. Depending on the acidity and the ageing conditions, different morphologies of brookite nanoparticles are obtained, namely spheroidal particles or platelets. Stable sols of pure brookite are obtained by peptisation of the solid phase. 30 refs.