Hydrothermal synthesis and luminescence properties of nanospherical SiO2@LaPO4:Eu3+ (5%) composite

Spherical SiO2 nanoparticles, prepared by sol-gel technique, were successfully coated by LaPO4:Eu3+ (5%) layer via hydrothermal method in a pH range of 8-11. Luminescent nanoparticles of SiO2 @LaPO4:Eu3+ composite were obtained after annealing at 900 degrees C for 3 h. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectra, chromatic coordinates as well as lifetimes were used to characterize the obtained products. The obtained composite phosphors have perfectly spherical shape with a narrow size distribution, without-agglomeration, and a smooth surface. The emission intensity ratio and life time of the LaPO4:Eu3+(5%) shells increase after forming the composite SiO2@LaPO4:Eu3+. The chromatic coordinates, dominant wavelength and color purity of the obtained products were determined, discussed and compared to other luminophores. An enhancement of LaPO4:Eu3+(5%) fluorescence properties after depositing it on the SiO2 core was revealed which effectively contributes to the rare earth saving and cost reduction. The registered fluorescence performances, compared to other luminophores, reveal the efficiency of the synthesis route and promote the usefulness of the composite SiO2@LaPO4 :Eu3+ in solar cells, fluorescent labeling, biotechnology, bio-imaging, nano-engineering, drug delivery and tracing techniques. (C) 2018 Elsevier B.V. All rights reserved.