Rare-Earth-Modified Titania Nanoparticles: Molecular Insight into Synthesis and Photochemical Properties
| Autor: | Gulaim A. Seisenbaeva, Carmen Tiseanu, Vasile I. Parvulescu, Bogdan Cojocaru, Fredric G. Svensson, Vadim G. Kessler, Zhen Qiu, Tomas Edvinsson |
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| Rok vydání: | 2021 |
| Předmět: |
Oorganisk kemi
Anatase Solid-state chemistry Materialkemi chemistry.chemical_element Article Inorganic Chemistry symbols.namesake chemistry X-ray photoelectron spectroscopy Chemical engineering Rutile Materials Chemistry Photocatalysis symbols Physical and Theoretical Chemistry Raman spectroscopy Spectroscopy Titanium |
| Zdroj: | Inorganic Chemistry |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/acs.inorgchem.1c02134 |
| Popis: | A molecular precursor approach to titania (anatase) nanopowders modified with different amounts of rare-earth elements (REEs: Eu, Sm, and Y) was developed using the interaction of REE nitrates with titanium alkoxides by a two-step solvothermal–combustion method. The nature of an emerging intermetallic intermediate was revealed unexpectedly for the applied conditions via a single-crystal study of the isolated bimetallic isopropoxide nitrate complex [Ti2Y(iPrO)9(NO3)2], a nonoxo-substituted compound. Powders of the final reaction products were characterized by powder X-ray diffraction, scanning electron microscopy–energy-dispersive spectroscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy, and photoluminescence (PL). The addition of REEs stabilized the anatase phase up to ca. 700 °C before phase transformation into rutile became evident. The photocatalytic activity of titania modified with Eu3+ and Sm3+ was compared with that of Degussa P25 titania as the control. PL studies indicated the incorporation of Eu and Sm cations into titania (anatase) at lower annealing temperatures (500 °C), but an exclusion to the surface occurred when the annealing temperature was increased to 700 °C. The efficiency of the modified titania was inferior to the control titania while illuminated within narrow wavelength intervals (445–465 and 510–530 nm), but when subjected to a wide range of visible radiation, the Eu3+- and Sm3+-modified titania outperformed the control, which was attributed both to doping of the band structure of TiO2 with additional energy levels and to the surface chemistry of the REE-modified titania. Molecular insight into the mechanism of solution−combustion synthesis provided clues to understanding the photocatalytic properties of rare-earth-doped nanotitania. |
| Databáze: | OpenAIRE |
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