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Among various kinds of photothermal conversion materials, polypyrrole (PPy) has attracted ever‐increasing attention because of its good biocompatibility and excellent near‐infrared light response property. In this research, the core‐shell nanoparticles with magnetic Fe3O4 as the core and mesoporous silica (MSN) as the shell were prepared, the resulted Fe3O4@MSN nanoparticles were then surface coated with a layer of PPy and further modified with polyvinylpyrrolidone (PVP) to gain colloidal stability. The Fe2+ in Fe3O4 can catalyze the decomposition of H2O2 in tumor cells to produce cytotoxic hydroxyl radicals, thus realizing the tumor chemodynamic therapy. Meanwhile, the MSN layer gives the nanoparticles a higher drug loading capacity of chemotherapeutics (doxorubicin, DOX). Therefore, the prepared Fe3O4@MSN@PPy‐PVP nanoparticles not only have good biocompatibility, magnetism and colloidal stability but also can realize the combined tumor photothermal, chemo, and chemodynamic therapy. This study demonstrates the rational design of multifunctional nanoplatforms for biomedical applications. [ABSTRACT FROM AUTHOR]

A family of eulytite-type orthophosphate phosphors with formula Ba3La(PO4)3:Eu2+,Mn2+ (BLaP:Eu2+,Mn2+) were studied by using a combination of Rietveld powder structure refinement and photoluminescence. The crystal structure of the obtained phosphors was refined using a split-atom model, where the oxygen atoms are distributed over several partially occupied sites. The Rietveld refinement analysis confirm that the BLaP:0.005Eu2+,0.06Mn2+ phosphor crystallizes in a cubic system (space group I4̅3d, no. 220) with unit cell parameters: a = b = c = 10.4817 Å and Z = 4. The La3+/Ba2+/Eu2+/Mn2+ cations are disordered on a single site with the special Wyckoff position (16c), while the oxygen anions occupy the general Wyckoff position (48e) and two oxygen atom sites were identified in the crystal structure. According to the luminescence spectra and fluorescence decay curves, we confirm that the energy transfer process from the Eu2+ to Mn2+ ions takes place in the BLaP:Eu2+,Mn2+ phosphors system. The possible energy transfer mechanism was proposed in terms of the experimental results and analysis. In addition, the relationship between the red shift of Mn2+ emission and its doping concentration was studied as well. Utilizing the red shift of Mn2+ emission and the energy transfer from Eu2+ to Mn2+, the emission colors can be tuned from yellowish-green through yellow, orange, and ultimately to reddish-orange by appropriately adjusting the Mn2+ concentration. [ABSTRACT FROM AUTHOR]

Herein, a series of Eu2+&Mn2+substituted fluorophosphates Ca6Gd2Na2(PO4)6F2 phosphor with apatite structure have been synthesized and investigated by the powder X-ray diffraction, photoluminescence spectra, fluorescence decay curves, thermal quenching, and chromaticity properties. Particularly, both Eu2+ and Mn2+ emissions at the two different lattice sites 4 f and 6 h in Ca6Gd2Na2(PO4)6F2 matrix have been identified and discussed. The dual energy transfer of Eu2+→Mn2+ and Gd3+→Mn2+ in Ca6Gd2Na2(PO4)6F2:Eu2+,Mn2+ samples have been validated and confirmed by the photoluminescence spectra. The dependence of color-tunable on the activator concentration of Mn2+ was investigated to realize white light emission. By varying the doping concentration of the Mn2+ ion, a series of tunable colors including pure white light and candle light are obtained under the excitation of 350 nm. Moreover, the fluorescence decay curves have been fitted and analyzed using the Inokuti-Hirayama theoretical model to estimate the Eu-Mn interaction mechanism. We also investigated temperature-dependent photoluminescence quenching characteristics according to the Arrhenius equation. Preliminary studies on the properties of the phosphor indicated that the obtained phosphors might have potential application as a single-component white-emitting phosphor for UV-based white LEDs. [ABSTRACT FROM AUTHOR]