 |
 |
|
Bagghi, A., Deniard, P., Cartigny, Y. & Dessapt, R. (2024) Na7[SbW6O24]: a new type of turn-off luminescence humidity sensor based on a lanthanide-free polyoxometalate. J. Mater. Chem. C,
Added by: Richard Baschera (2024-01-19 15:14:15) Last edited by: Richard Baschera (2024-01-19 15:18:27) |
| Type de référence: Article DOI: 10.1039/D3TC03604A Numéro d'identification (ISBN etc.): 2050-7534 Clé BibTeX: Bagghi2024 Voir tous les détails bibliographiques  |
Catégories: MIOPS Créateurs: Bagghi, Cartigny, Deniard, Dessapt Collection: J. Mater. Chem. C |
Consultations : 1/11
Indice de consultation : 2% Indice de popularité : 0.5% |
| Liens URLs https://pubs.rsc.o ... 2024/tc/d3tc03604a |
| Résumé |
|
A new type of turn-off photoluminescence (PL) humidity sensor based on a water-responsive anhydrous alkali lanthanide-free [SbW6O24]7− polyoxometalate (POM) is reported. Na7[SbW6O24] (NaSbW6) was recently obtained by heating its parent hydrate Na7[SbW6O24]·16H2O (NaSbW6·16H2O) at 200 °C. Upon exposure to a moisture-laden atmosphere at room temperature, the anhydrous phase converted back to the hydrated one, leading to a complete quenching of the intense PL intensity. The present work thoroughly investigates the dehydration/rehydration processes of these materials and their precise impact on their PL responses. First, the complete thermal dehydration of NaSbW6·16H2O involves the progressive formation of two intermediary hydrates, Na7[SbW6O24]·10H2O (NaSbW6·10H2O) and Na7[SbW6O24]·4H2O (NaSbW6·4H2O) which has been characterised by a combination of powder X-ray diffraction (PXRD) analysis, optical microscopy and FT-Raman spectroscopy at variable temperatures. The crystal structure of NaSbW6·10H2O has been solved from ab initio powder X-ray diffraction determination, revealing structural similiarities with NaSbW6·16H2O. The humidity-dependent stability of the (an)hydrated phases has been also investigated by dynamic vapor sorption (DVS) and PXRD analyses under variable relative humidity (RH). The room-temperature PL properties of NaSbW6·10H2O and NaSbW6·4H2O have been characterised, and their photophysical parameters determined and compared with those of NaSbW6·16H2O and NaSbW6 recently reported. The PL efficiency of the four materials gradually increases with decreasing their degree of hydration, due to the progressive deletion of non-radiative deactivation pathways caused by O–H vibrators connecting the emitting POM unit. NaSbW6 exhibits humidity-mediated transformations into the three hydrated phases, and its PL response to RH is linear in three distinct ranges. The best sensitivity is observed within the RH range of 0–23%, with a limit of detection of 2.2% RH.
|
| Notes |
|
Publisher: The Royal Society of Chemistry
|