New phosphors based on the reduction of Eu(III) to Eu(II) in ion-exchanged aluminosilicate and gallium silicate inorganic polymers
| Autor: | Joanne J. Rogers, Gregory J. Rees, John V. Hanna, Kenneth J. D. MacKenzie |
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| Rok vydání: | 2018 |
| Předmět: |
Inorganic polymer
Photoluminescence Materials science Process Chemistry and Technology Inorganic chemistry chemistry.chemical_element Phosphor 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Silicate 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Geopolymer chemistry.chemical_compound chemistry X-ray photoelectron spectroscopy Aluminosilicate Materials Chemistry Ceramics and Composites Gallium 0210 nano-technology |
| Zdroj: | Ceramics International. 44:1110-1119 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2017.10.066 |
| Popis: | Novel blue-emitting phosphors based on Eu2+ ions dispersed within chemosynthetic aluminosilicate and gallium silicate inorganic polymer (geopolymer) hosts were prepared by heat treatment of Eu3+-exchanged inorganic polymers in reducing conditions and investigated using photoluminescence spectroscopy, 29Si, 27Al and 71Ga MAS NMR spectroscopy, XRD, and XPS. Eu2+ photoluminescence could be distinguished from the photoluminescence of the inorganic polymer host after heating at ≥ 400 °C in the case of the aluminosilicate inorganic polymer and ≥ 600 °C in the case of the gallium silicate inorganic polymer and became more intense as the reduction temperature was increased up to 1000 °C. The gallium silicate-based phosphors heated at ≥ 900 °C contained small amounts of crystalline KGaSi2O6 or β-Ga2O3, but the X-ray amorphous structure of the inorganic polymer was retained. After heating at 1000 °C, the Eu2+ photoluminescence intensity was substantially more intense for the aluminosilicate phosphor, but the shape of the excitation and emission spectra of the aluminosilicate and gallium silicate phosphors were similar, with a broad emission band centred at 440–475 nm when excited at 240–400 nm. This band shifted to longer wavelengths as the ion exchange solution concentration was increased from 0.001M to 0.03 M. |
| Databáze: | OpenAIRE |
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