Lanthano phosphomolybdate-decorated silica nanoparticles: novel hybrid materials with photochromic properties

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Tania V Pinto (Author) Other; Diana M Fernandes (Author) Other; Clara Pereira (Author) FCUP; Guedes, A (Author) FCUP; Ginesa Blanco (Author) Other; Jose M Pintado (Author) Other; Manuel F R Pereira (Author) Other; Cristina Freire (Author) FCUP

Journal

Title: Dalton Transactions

Vol. 44

Pages: 4582-4593

ISSN: 1477-9226

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 13 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-00A-94G

DOI: 10.1039/c5dt00090d

Abstract (EN): Novel photochromic hybrid nanomaterials were prepared through the immobilization of the lacunary Keggin-type phosphomolybdate (TBA(4)H(3)[PMo11O39]center dot xH(2)O, denoted as PMo11) and sandwich-type lanthano phosphomolybdates (K-11[Ln(III)(PMo11O39)(2)]center dot xH(2)O, denoted as Ln(PMo11)(2), where Ln(III) = Sm, Eu, Gd, Tb and Dy) onto positively-charged functionalized silica nanoparticles. The functionalized silica nanoparticles were prepared by a one-step co-condensation route between tetraethyl orthosilicate and dimethyloctadecyl[3-(trimethoxysilyl) propyl] ammonium chloride, presenting an average particle size of 95 +/- 26 nm, a spherical morphology and a pore diameter of 13.7 nm. All characterization techniques proved the successful immobilization of the phosphomolybdates. The photochromic properties of the resulting hybrid nanomaterials in the solid state were evaluated by UV-Vis spectroscopy and colorimetry. All materials revealed promising photochromic properties under UV irradiation (lambda = 254 nm). The lacunary phosphomolybdate anchored onto the silica nanoparticles, C18-SiO2@ PMo11, showed the best photo-switching properties, with the color changing from green to dark-blue (Delta E* = 26.8). Among the Ln (PMo11)(2)-based hybrid nanomaterials, those containing higher Mo loadings - Eu-III - and Tb-III -based samples - presented more significant color changes from green to dark-blue (Delta E* = 18.8-18.9). These results revealed that the optical properties of the as-prepared hybrid nanomaterials did not depend directly on the type of LnIII cation, but only on the amount of Mo, which was the target element responsible for the photochromic behavior.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12