Abstract: Deposition of a SiO2 coating on anatase TiO2 nanocrystals is shown to improve their thermal stability. As low as 0.5% Si was shown to preserve the small anatase crystallite size after calcination at 600 °C. Such treatment led to considerable sintering of TiO2 nanocrystals without the silica with the average particle size growth from 9 to 50 nm, surface area decrease from 135 to 22 m2/g and partial anatase conversion to rutile. The phase composition, crystallite size, and surface area of 5%Si-TiO2 samples were largely preserved till the temperatures as high as 800 °C whereas the anatase phase was mostly stably even after calcination at 1000 °C. The phase transformation from anatase to rutile in xerogel TiO2 and TiO2@SiO2 samples apparently did not occur until the crystallites grew larger than the critical size about 50 nm. Electron-acceptor sites capable of ionizing perylene to its radical cations were observed on all samples with anatase crystalline structure. So, the silica shell deposition improves the TiO2 thermal stability without limiting access to the surface active sites.

Cite: Bedilo A.F. , Shuvarakova E.I. , Volodin A.M.
Silica-Coated Nanocrystalline TiO2 with Improved Thermal Stability
Ceramics International. 2019. V.45. N2. P.3547-3553. DOI: 10.1016/j.ceramint.2018.11.013 WOS Scopus РИНЦ AN OpenAlex

Dates:

Submitted:	Sep 28, 2018
Accepted:	Nov 3, 2018
Published online:	Nov 3, 2018
Published print:	Feb 15, 2019

Identifiers:

Web of science:	WOS:000456225900079
Scopus:	2-s2.0-85056186005
Elibrary:	38578822
Chemical Abstracts:	2018:2138493
OpenAlex:	W2899146963

Citing:

DB	Citing
Scopus	11
Web of science	8
Elibrary	6
OpenAlex	6

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