Large‐scale fabrication of upconversion nanoparticles (UCNPs)/TiO2 nanofiber mats is achieved via electrospinning, followed by calcination. The as‐prepared UCNPs/TiO2 nanofiber mats consist of nanofibers of TiO2 embedded with UCNPs of NaYF4:Yb/Tm@NaYF4, confering strong upconversion fluorescence under near‐infrared excitation (980 nm) and enabling efficient degradation of organic dyes via fluorescence resonance energy transfer between UCNPs and TiO2.

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A facile sequential growth process is developed to synthesize uniform lanthanide‐doped upconversion (UC) core–shell nanoparticles with controlled nanostructures and enhanced UC fluorescence, which provides an important tool for their extensive applications in the near future.

Upconversional core-shell nanostructures have gained considerable attention due to their distinct enhanced fluorescence efficiency, multifunctionality, and specific applications. Recently, we have developed a sequential growth process to fabricate unique upconversion core-shell nanoparticles. Time evolution of morphology for the NaYF:Yb/Er@NaGdF nanodumbbells has been extensively investigated. An Ostwald ripening growth mechanism has been proposed to illustrate the formation of NaYF:Yb/Er@NaGdF nanodumbbells. The hydrophilic NaYF:Yb/Er@NaGdF core-shell nanodumbbells exhibited strong upconversion fluorescence and showed higher magnetic resonance longitudinal relaxivity (r = 7.81 mM s) than commercial contrast agents (Gd-DTPA). NaYF:Yb/Er@NaGdF nanodumbbells can serve as good candidates for high efficiency fluorescence and magnetic resonance imaging.

CrystEngComm COVER ARTICLEQian, Zhang et al. Silica/ultrasmall Ag composite microspheres: facile synthesis, characterization and antibacterial and catalytic performance Volume Uniform silica/ultrasmall silver composite microspheres have been prepared from [Ag(NH 3 ) 2 ] + in the presence of silica microspheres via a hydrothermal process. The reaction temperature plays a critical role in the formation of the as-prepared SiO 2 /ultrasmall Ag composite microspheres. The as-prepared product was investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM, JEOL-6700F) and transmission electron microscopy (TEM, JEOL 3010). The silica/ultrasmall silver composite microspheres are 200 nm in diameter and the silica microspheres decorated with ultrasmall Ag nanoparticles have an average diameter of 4 nm. As expected, the as-prepared silica/ultrasmall silver composite microspheres exhibit superior bacteriostatic and bactericidal activities and excellent photodecomposition towards Rhodamine 6G (R6G) dyes.