Surface and photocatalytic properties of sol–gel derived TiO2@SiO2 core-shell nanoparticles

Авторы:
Shilova O.A., Kovalenko A.S., Nikolaev A.M., Mjakin S.V., Sinelnikov A.A, Chelibanov V.P., Gorshkova Yu.E., Tsvigun N.V., Ruzimuradov O., Kopitsa G.P.
Авторы из ОИКС:
Год публикации:
2022
Журнал:
Journal of Sol-Gel Science and Technology
Ключевые слова:
TiO2 nanoparticles, Anatase, Surface modification, Core-shell structure, Supramolecular structure
Абстракт:

The surface of TiO2 nanoparticles was modified with silica prepared by acid hydrolysis of tetraethoxysilane followed by polycondensation. A comparative characterization of the initial and modified nanoparticles by TEM, XRD, specific surface area and ζ-potential measurements as well as the estimation of the surface acid-base properties via dynamic pH measurements revealed that the applied surface modification provided almost no changes in the phase composition, crystallite size range (~16 nm) and mesostructure of the initial anatase nanoparticles, but resulted in a more than twofold increase in the specific surface area and change of the surface functionality from a prominent Lewis acidity toward a relatively weak Broensted acidity. The resulting TiO2@SiO2 “core-shell” particles are shown to exhibit a significant enhancement of singlet oxygen generation compared with the initial TiO2. In conjunction with increased specific surface and modification of the surface centers, this effect promoted a drastic growth of photocatalytic activity indicated by an almost 90% degradation of methylene blue dye upon UV irradiation.

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