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

Abstract

Nanometric particles of titania, brookite and rutile polymorphs were synthesised by thermolysis of TiCl 4 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 (OH 2 ) 2 seems 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 peptization of the solid phase.

How Should Iron and Titanium be Combined in Oxides to Improve Photoelectrochemical Properties?

“…[66][67][68][69][70][71][72][73] Much less is known about the ternary Ti-Fe-O diagram when dealing with nanoparticle synthesis in water. [74][75][76] In the 2-6 pH range, both metal ions first form an amorphous or very poorly organized hydroxide precipitate.…”

The Influence of Acids on Tuning the Pore Size of Mesoporous TiO2 Templated by Non‐Ionic Block Copolymers

“…Besides, the pure anatase phase suggests negligible effect of Cl -, NO 3 -and ClO 4 -anions on the TiO 2 phase formation even though these species are known to stabilize rutile and brookite. [16][17][18] The SAXRD of TiO 2 and TiO 2 HA1M ( Figure 1B) shows a broad intense peak centered at 1.5°. Although the Bragg reflections of the space group are not resolved, the presence of a low angle diffraction peak suggests that the samples possess a semi-organized mesoporous structure with relative uniform pores, but without long range ordering.…”

Hydrothermal synthesis of hierarchical TiO2 microspheres using a novel titanium complex coordinated by picolinic acid

“…Our study demonstrated that the desired crystalline structure and morphology can be controlled at the molecular level by selection of a compound with an appropriate coordination architecture. Journal of the Ceramic Society of Japan 119 [6] 513-516 2011…”