Transformation of Amorphous TiO2 Into Crystalline Materials

Abstract

TiO2 is used in a variety of photochemical applications including catalysis, antibacterial coatings and dye-sensitized solar cells. The transformation of amorphous TiO2 into the three most common phases, anatase, rutile and brookite has been achieved under the appropriate experimental conditions. The amorphous TiO2 was obtained by adding titanium isopropoxide to isopropanol with a low concentration of water. A paste of amorphous titania was then mixed with different reactants and hydrothermally treated at elevated temperature in order to obtain a crystalline phase. Anatase nanoparticles were obtained by using acetic acid, while rutile nanoparticles were obtained using HCl. Titanates were formed with LiOH and KOH as reactants, while the use of NaOH results in brookite particles (>200 nm) after the formation of titanates as intermediate. The materials were characterized with X-ray diffraction and SEM.

Brookite-Based Dye-Sensitized Solar Cells: Influence of Morphology and Surface Chemistry on Cell Performance

“…The amorphous titania was obtained by filtering the suspension solution three times. 35 Pure anatase was synthesized by hydrothermal treatment of an aqueous solution containing 0. at 200 °C for 6 h. The final product was washed several times with deionized water and ethanol and dried at 80 °C. Brookite was synthesized using two different treatments, using either an acidic or basic solution.…”

“…Thereafter, the suspension was maintained under stirring for 24 h at room temperature. The amorphous titania was obtained by filtering the suspension solution three times …”