Core-shell Rare Earth Composite: Preparation, Characterization And Properties

In recent years, hollow nanostructures have attracted considerable interest because of theirunique properties, such as high surface area, tunable and uniform pore size and volume, lowmass density, non-toxic nature, easily modified surface properties, and good biocompatibility,which can improve their unique optical, electrical, mechanical, and biomedical properties.This article was devoted to the progress made in synthesis and applications of hollowmicro-/nanostructures. First, we made use of the hydrothermal method to prepare theironoxide（Fe₃O₄） with different condition and size, the St ber Sol-gel method to fabricatedFe₃O₄@SiO₂, and selective eaching for Fe₃O₄to form hollow mesoporous silica spheres（HMSs）. Moreover, we presented a comprehensive overview of synthetic strategies for thecomposite materials based on these HMSs. These strategies were broadly categorized into twothemes, well defined spherical HMSs@YBO₃:Eu³⁺and HMSs@Gd₂O₃:Yb³⁺,Ln³⁺（Ln=Tm、Er、 Ho）had been successfully synthesized using Sol-gel method and impregnation processrespectively. Therefore, we obtained the core-shell Multi-function material materials withmesoporous and fluorescence, which could be used as carriers for drug（DOX） release.In this thesis, the core-shell structure of rare earth nanomaterials had been discussedandcharacterized the structure and surface of the prepared samples by thetestinstrument（XRD、SEM、TEM、EDS、FT-IR、N2adsorption and PL spectrum）, whichconfirmed the core-shell structure of the multifunctional materials had been successfullyprepared.The research results helped to resolve the problem of preparing the spherical rareearth hollow nanocompositesdirectly. We explored the optimal conditions for coating, andtherefore using HMSs as the part of core-shell phosphors with large hollow structure, highbiological activity and favourable luminescent intensity were achieved. In addition, using theinorganic silica sphere as cores, not only can reduce the cost of phosphor, butalso save rareearth resource of our country.