Characteristics of Nanostructures Formed during the Heat Treatment of Titanium (IV) Isopropoxide Precipitates in the Presence of Noble Metals

Titanium-based nanostructures were formed by the co-precipitation of titanium (IV) isopropoxide (TTIP) aqueous ethanol solutions with noble metal (NM) solutions in a weakly alkaline medium. It was found that regardless of the presence and nature of NM, only the anatase phase was identified by XRD method in the powders obtained at
$\mathbf{T}= 600\ {{}^{\circ}}\mathbf{C}$
. The incorporation of NM into anatase structure was confirmed by varying the crystal lattice parameters and CSR. The increase in calcination temperature of the samples to
$1000\ {{}^{\circ}}\mathbf{C}$
shows that only the rutile phase was determined for the TiO
2
&Pd system, while three polymorphic modifications of TiO
2
(anatase, rutile, and brookite) have been identified in pure TiO
2
, TiO
2
&Au, and TiO
2
&Pt systems. The anatase phase was transformed into rutile in TiO
2
&Pd system (TG-DTA) at
$\mathbf{T} =780\ {{}^{\circ}\mathbf{C}}$
, whereas the same reflex was not detected in other studied systems. The average particle size of anatase was increased from
$\sim 30$
to
$\sim 300$
nm after heating temperature increasing from 600 to 1000 °C. The shape of anatase and rutile particles (tetragonal system) was close to spherical type, but the brookite phase was represented by plates (hexagonal system).