Eu³⁺and Tb³⁺doped LaPO₄nanorods, modified with a luminescent organic compound, exhibiting tunable multicolour emission

Abstract

Co-precipitation reaction followed by hydrothermal treatment were used to synthesise Eu 3+ or Tb 3+ doped LaPO 4 nanorods, of 5-10 nm in width and 50-100 nm in length. Surface modification of the as-prepared nanoparticles with a selected luminescent organic compound resulted in formation of hybrid inorganicorganic nanomaterials. The products obtained exhibited tunable multicolour luminescence, dependent on the surface modification and applied excitation wavelength. The colour of their emission can be altered from red-orange to yellow-green. Powder X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM) confirmed the structure and morphology of the products synthesized. Successful surface modification of the nanophosphors was evidenced by analytical and spectroscopic techniques such as dynamic light scattering (DLS)providing size distribution histograms and zeta potentials of the nanoparticles; IR spectroscopy and elemental analysis which proved the presence of an organic phase in the structure; spectrofluorometry (excitation/emission spectra and luminescence decay curves) which confirmed the formation of hybrid, surface modified nanomaterials revealing tunable multicolour emission.

Silica‐modified luminescent LaPO4:Eu@LaPO4@SiO2 core/shell nanorods: Synthesis, structural and luminescent properties

“…The observed strong infrared band of OH revealed that abundant OH groups in H 2 O exist on the surface of nano‐products, and play a key role in their solubility, colloidal stability, and conjugation with bio‐macromolecules. Observed characteristic infrared peaks at 1047, 613 and 536 cm −1 were assigned to the stretching and bending vibrational modes of the phosphate (PO 4 3− ) group . Silica surface modification of the surface of the core/shell NRs was confirmed by characteristic silica peaks of silica at 1080, 603, 515, and 463 cm −1 , which can be assigned to Si–O–Si, Si–OH, and Si–O stretching and bending vibrations modes of surface functionalized amorphous silica .…”

“…The observed sharp transitions corresponded to the direct excitation of Eu 3+ from the ground state to the excited state arising from the 4 f manifold. Among the observed excitation peaks, the 7 F 0 → 5 L 6 transition at 393 nm was the most prominent and showed the greatest sensitivity in the spectrum …”

“…Gupta and colleagues explored the host‐dopant energy transfer dynamic and luminescence properties of monoclinic LaPO 4 :Eu nanoparticles. Another report on Eu‐doped LaPO 4 NRs that examined the tunable multicolor emission was reported by Runowski and colleagues . Other reports have also demonstrated the luminescence properties of LaPO 4 :Eu nanomaterials (NMs) and the influence of different morphologies on their photoluminescence and structural properties .…”

Synthesis, surface modification/decoration of luminescent–magnetic core/shell nanomaterials, based on the lanthanide doped fluorides (Fe 3 O 4 /SiO 2 /NH 2 /PAA/LnF 3 )

“…Eu 3 þ -red, Tb 3 þ -green) [8,[21][22][23]. They reveal also long luminescence lifetimes (several ms), narrow emission bands and a photostability [22,24,25].…”

“…They can exhibit simultaneously two or more functionalities, namely tuneable multicolor luminescence, magnetic response, plasmonic properties, biological activity, drug-delivery capability, catalytic activity, etc. [8][9][10][11][12][13][14]. The multifunctionality and possibility of alterations of their properties are crucial factors promoting development of such nanocomposites and hybrid nanomaterials.…”