Low-Temperature Sol–Gel Synthesis and Photoactivity of Nanocrystalline TiO2 with the Anatase/Brookite Structure and an Amorphous Component

• Published in: Kinetics and catalysis Vol. 60; no. 3; pp. 325 - 336
• Main Authors: Kozhevnikova, N. S., Ul’yanova, E. S., Shalaeva, E. V., Zamyatin, D. A., Bokunyaeva, A. O., Yushkov, A. A., Kolosov, V. Yu, Buldakova, L. Yu, Yanchenko, M. Yu, Gorbunova, T. I., Pervova, M. G., Enyashin, A. N., Vorokh, A. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-05-2019; Springer Nature B.V
• Subjects: Anatase; Brookite; Catalysis; Charge transfer; Chemistry; Chemistry and Materials Science; Current carriers; Electronic structure; Hydroquinone; Low temperature; Organic chemistry; Oxidation; Photocatalysis; Physical Chemistry; Quantum chemistry; Raman spectroscopy; Sol-gel processes; Titanium dioxide; Transmission electron microscopy; X-ray diffraction; photocatalytic properties; quantum chemical calculations; titanium dioxide; polymorphism; sol–gel method; nanostructures
• ISSN: 0023-1584; 1608-3210
• DOI: 10.1134/S002315841903008X

Nanodispersed TiO
2
consisting of anatase and brookite phases in a ratio of 3 : 1 is obtained by the sol–gel method from titanium(IV) butoxide at a temperature below 100°C. X-ray diffraction, transmission electron microscopy, and Raman spectroscopy are used to show that the size of anatase particles is about 6 nm, and brookite particles consist of a crystal core, 4 nm in diameter, surrounded by an amorphous shell. Compared with the commercial Degussa P25 photocatalyst, which consists of the anatase and rutile phases in the same 3 : 1 ratio, the resulting TiO
2
exhibits an increased photoactivity in hydroquinone oxidation. Quantum chemical modeling of anatase and brookite surfaces as well as their interface does not reveal the specific features of their electronic structure. This fact is indicative of the amorphous phase as an active participant in the transfer of charge carriers in the photocatalytic process.