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YVO4nano/microcrystals with multiform morphologies, such as nanoparticles, microdoughnut, micropancake, pillar structure, and microflower, have been synthesized via a facile hydrothermal route. A series of controlled experiments indicate that the shape and size of as-prepared architectures can be tuned effectively by controlling the reaction conditions, such as reaction time, vanadium sources, different organic additives, and the molar ratio of organic additive trisodium citrate (Cit3−):Y3+. It is found that Cit3−as a ligand and shape modifier has the dynamic effect by adjusting the growth rate of different facets under different experimental conditions, resulting in the formation of various geometries of the final products. The possible formation mechanisms for products with diverse architectures have been presented in detail. Additionally, we systematically investigate the luminescent properties of the YVO4:Ln3+(Ln = Eu, Dy, Sm, and Er). Because of an efficient energy transfer from vanadate groups to dopants, YVO4:Ln3+(Ln = Eu, Dy, Sm, and Er) phosphors showed their strong characteristic emission under ultraviolet excitation and low-voltage electron beam excitation. The ability to generate YVO4nano/microstructures with diverse shapes, multicolor emission, and higher quantum efficiency provides a great opportunity for systematically evaluating their luminescence properties, as well as fully exploring their applications in many types of color display fields.

When orthopedic joints coated by hydroxyapatite (HA) were implanted in the human body, they release wear debris into the surrounding tissues. The generation and accumulation of wear particles will induce aseptic loosening. However, the potential bioeffect and mechanism of HA-coated orthopedic implants on bone cells are poorly understood. In this study, defect-related luminescent bur-like hydroxyapatite (BHA) microspheres with the average diameter of 7–9 μm which are comparable to that of the wear-debris particles from aseptically loosened HA implants or HA debris have been synthesized by hydrothermal synthesis and the MC3T3-E1 cells were set as a cells model to study the potential bioeffect and mechanism of BHA microspheres. The studies demonstrated that BHA microspheres could be taken into MC3T3-E1 cells via endocytosis involved in micropinocytosis- and clathrin-mediated endocytosis process, and exert cytotoxicity effect. BHA microspheres could induce the cell apoptosis by intracellular production of reactive oxygen species (ROS), which led to not only an increase in the permeability of lysosome and release of cathepsins B, but also mitochondrial dysfunction and DNA damage. Our results provide novel evidence to elucidate their toxicity mechanisms and might be helpful for more reasonable applications of HA-based orthopaedic implants in the future.

The phase instability of CsPbI3perovskite quantum dots (PQDs) restricts their practical applications due to the easy conversion from the luminescent cubic phase to the non-luminescent orthorhombic phase. The elemental doping route has been regarded as one of the most effective strategies to achieve high-quality PQDs-based phosphors. Herein, a stoichiometric amount of nickel chloride (NiCl2) has been effectively doped into the CsPbI3lattice. The incorporation of Ni2+ions has little effect on the crystal phase, structure, and morphology of the CsPbI3PQDs but greatly influences their luminescence properties. The Ni2+doping not only improves the luminescence performance but also greatly enhances the stability against temperature, storage time, and polar solvent. The formation process and luminescence and stability improvement mechanisms have been discussed. Moreover, the influence of a series of other metal chlorides (KCl, NaCl, MgCl2, ZnCl2, SnCl2, and CaCl2) on the luminescence performance of CsPbI3PQDs has been systematically investigated, revealing that the luminescence intensity increases by introducing CaCl2, SnCl2, or ZnCl2but decreases after doping MgCl2, NaCl, or KCl into the CsPbI3lattice. The as-proposed doping strategy may have a significant impact on tackling the intrinsic instability of all-inorganic CsPbX3PQDs, shedding light on their future applications in light-emitting diode (LED) devices and solid-state lighting.

The rare earth hollow spheres with up-conversion luminescence properties have shown potential applications in drug delivery and bioimaging fields. However, there have been few reports for the degradation properties of rare earth oxide drug carriers. Herein, uniform and well-dispersed Y2O3:Yb3+,Er3+hollow spheres (YOHSs) have been fabricated by a general Pechini sol–gel process with melamine formaldehyde colloidal spheres as template. The novel YOHSs with up-conversion luminescence has good drug loading amount and drug-release efficiency; moreover, it exhibits pH-responsive release patterns. In particular, the YOHSs sample exhibits low cytotoxicity and excellent degradable properties in acid buffer. After the sample was loaded with anticancer drug doxorubicin (DOX), the antitumor result in vitroindicates that YOHS-DOX might be effective in cancer treatment. The animal imaging test also reveals that the YOHSs drug carrier can be used as an outstanding luminescent probe for bioimaging in vivoapplication prospects. The results suggest that the degradable drug carrier with up-conversion luminescence may enhance the delivery efficiency of drugs and improve the cancer therapy in clinical applications.

Novel defect-related hydroxyapatite (DHAP), which combines the advantages of HAP and defect-related luminescence, has the potential application in tissue engineering and biomedical area, because of its excellent capability of monitoring the osteogenic differentiation and material biodegradation. Although the extracellular mechanism of DHAP minerals and PO43–functioning in osteogenic differentiation has been widely studied, the intracellular molecular mechanism through which PO43–mediates osteogenesis of bone mesenchymal stem cells (BMSCs) is not clear. We examined a previously unknown molecular mechanism through which PO43–promoted osteogenesis of BMSCs with an emphasis on adenosine–triphosphate (ATP)-induced cAMP/PKA pathway. Our studies showed that DHAP could be uptaken into lysosome, in which PO43–was released from DHAP, because of the acid environment of lysosome. The released PO43–interacted with ADP to form ATP, and then degraded into adenosine, an ATP metabolite, which interacted with A2b adenosine receptor to activate the cAMP/PKA pathway, resulting in the high expression of osteogenesis-related genes, such as Runx2, BMP-2, and OCN. These findings first revealed the function of ATP-metabolism in bone physiological homeostasis, which may be developed to cure bone metabolic diseases.

Potential bioaccumulation is one of the biggest limitations for silica nanodrug delivery systems in cancer therapy. In this study, a mesoporous silica nanoparticles/hydroxyapatite (MSNs/HAP) hybrid drug carrier, which enhanced the biodegradability of silica, was developed by a one-step method. The morphology and structure of the nanoparticles were characterized by TEM, DLS, FT-IR, XRD, N2adsorption–desorption isotherms, and XPS, and the drug loading and release behaviors were tested. TEM and ICP-OES results indicate that the degradability of the nanoparticles has been significantly improved by Ca2+escape from the skeleton in an acid environment. The MSNs/HAP sample exhibits a higher drug loading content of about 5 times that of MSNs. The biological experiment results show that the MSNs/HAP not only exhibits good biocompatibility and antitumor effect but also greatly reduces the side effects of free DOX. The as-synthesized hybrid nanoparticles may act as a promising drug delivery system due to their good biocompatibility, high drug loading efficiency, pH sensitivity, and excellent biodegradability.

Uniform and well-dispersed walnut kernel-like mesoporous silica nanoparticles (MSNs) with diameters about 100 nm have been synthesized by a templating sol–gel route. After an annealing process, the as-obtained sample (DLMSNs) inherits the well-defined morphology and good dispersion of MSNs, and exhibits bright white-blue luminescence, higher specific surface area and pore volume, and better biocompatibility. The drug loading and release profiles show that DLMSNs have high drug loading capacity, and exhibit an initial burst release followed by a slow sustained release process. Interestingly, the luminescence intensity of the DLMSNs-DOX system increases gradually with the increase of cumulative released DOX, which can be verified by the confocal laser scanning images. The drug carrier DLMSNs can potentially be applied as a luminescent probe for monitoring the drug release process. Moreover, the DLMSNs-DOX system exhibits potent anticancer effect against three kinds of cancer cells (HeLa, MCF-7, and A549 cells).

Novel CuxS/Cu (1 < x<2) nanotubes were prepared by a facile wet chemical approach in polyethylene glycol (PEG). Here, Cu nanowires were presynthesized and then converted to nanotubes via a mass diffusion process. A thin PEG layer is physically adsorbed on the nanotube surface. The obtained CuxS/Cu nanotubes show good Li storage properties with stable cyclability upon Li ion insertion/extraction, which is attributed to the existence of the PEG capping and the reduced dissolution of Li polysulfides into the electrolytes. Furthermore, CuxS/Cu nanotubes with 10 wt % Cu show promising rate capabilities (a fifth-cycle discharge capacity of 282 mA h g–1at a current density of 5 A g–1) due to the enhanced kinetics of charge transfer.

A novel red emitting phosphor, Eu3+-doped Ca2GeO4 was prepared through the solid state reaction. We also replace Ca2+ with Mg2+ and Ba2+ ions and add Li+, Al3+ ions as charge compensators in the Ca2GeO4 host to improve the luminescence properties of Ca2GeO4:Eu3+ phosphor. XRD, FE-SEM, photoluminescence and cathodoluminescence spectra were utilized to characterize the samples. XRD reveals that pure Ca2GeO4 phase can be obtained at 1250degC and all the above cation substitutions can be achieved in a certain concentration range except for Ba2+ ion. FE-SEM images indicate that the Ca1.99GeO4:0.01Eu3+ sample and its substitutions consist of aggregated particles with size ranging from 0.5 to 2 um, and Ba1.99GeO4:0.01Eu3+ sample is composed of uniform and spindle-like structures with the size ranging from 300 to 500 nm. Under the excitation of ultraviolet light and low-voltage electron beams, the Ca2GeO4:Eu3+ phosphor shows the characteristic emissions of Eu3+ (5D0-7F2 at 613 nm, red). The optimum concentration for the luminescence Eu3+ is determined to be 0.01 in Ca2[?]xGeO4:xEu3+ phosphor. The luminescent intensity can be improved by co-doping the Mg2+ ions and charge compensators (Li+ and Al3+) to partially substitute of Ca2+ ions.

Luminescent and porous silica fibers have been successfully prepared by using the electrospinning process. The obtained multifunctional silica fibers, which possess a porous structure and display blue luminescence, can serve as a drug delivery host carrier, using ibuprofen (IBU) as a model drug, allowing the investigation of storage/release properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FT‐IR), N2adsorption/desorption, photoluminescence (PL) spectra, and kinetic decay were used to characterize the structural, morphological, and optical properties of the as‐obtained samples. The results reveal that the multifunctional silica materials exhibit an irregular porous structure, and display a fiberlike morphology with dimensions of several hundred nanometers in width and several millimeters in length. The obtained silica fibers exhibit an intense broad bluish emission, which might be attributed to impurities and/or defects in the silica fibers. The IBU‐loaded silica fiber system shows blue luminescence under UV irradiation and controlled release behavior for IBU. In addition, the emission intensities of silica fibers in the drug carrier system vary with the released amount of IBU, thus allowing the drug release to be easily tracked and monitored by the change of the luminescence intensity.

Luminescencefunctionalized silica composites were synthesized by deposition of CaWO4:Tb3+nanoparticles onto mesoporous silica MS materials by a Pechinitype sol–gel process. The pristine mesoporous silica materials comprise rodlike and spherical SBA15type silica materials in micron size, hollow silica spheres of around 2–4 μm, and silica tubes with lengths of tens of micrometers. The Xray diffraction XRD, transmission electron microscopy TEM, and N2adsorptiondesorption results confirm that the composites still conserve regular mesopore structure after the incorporation of the CaWO4:Tb3+nanoparticles. These luminescent composites possessing suitable pore size, high BET surface area, and large pore volume > 1.0 cm3g were studied as supports for immobilization of lysozymes. These composites show various lysozyme adsorption capacities at different solution pH values. CaWO4:Tb3+loaded SBA15type composites and hollow spheres adsorb relatively high amounts > 500 mgg composite at a solution pH of 10.0 of lysozyme LYZ. The different enzyme adsorption and release properties of these luminescent mesoporous silica materials make them good candidates for specific bioimmobilization hosts. The emission intensity of Tb3+in the CaWO4:Tb3+rodlike SBA15 varies with the total released amount of LYZ, which enables the lysozyme release to be tracked by the change in the luminescence intensity.

Highly uniform and well‐dispersed CaF2hollow spheres with tunable particle size (300–930 nm) have been synthesized by a facile hydrothermal process. Their shells are composed of numerous nanocrystals (about 40 nm in diameter). The morphology and size of the CaF2products are strongly dependent on experimental parameters such as reaction time, pH value, and organic additives. The size of the CaF2hollow spheres can be controlled from 300 to 930 nm by adjusting the pH value. Nitrogen adsorption–desorption measurements suggest that mesopores (av 24.6 nm) exist in these hollow spheres. In addition, Ce3+/Tb3+‐codoped CaF2hollow spheres can be prepared similarly, and show efficient energy transfer from Ce3+to Tb3+and strong green photoluminescence of Tb3+(541 nm, 5D4→7F5transition of Tb3+, the highest quantum efficiency reaches 77 %). The monodisperse CaF2:Ce3+/Tb3+hollow spheres also have desirable properties as drug carriers. Ibuprofen‐loaded CaF2:Ce3+/Tb3+samples still show green luminescence of Tb3+under UV irradiation, and the emission intensity of Tb3+in the drug‐carrier system varies with the released amount of ibuprofen, so that drug release can be easily tracked and monitored by means of the change in luminescence intensity. The formation mechanism and luminescent and drug‐release properties were studied in detail.

Uniform and well-dispersed SrF2hierarchical microspheres have been successfully synthesized by a facile and friendly hydrothermal method. The experimental results indicate that such 3D hierarchical SrF2microspheres with size about 1 μm are assembled by numerous nanocrystals (about 100 nm). Nitrogen adsorption−desorption measurement suggests that mesopores exist in these hierarchical microarchitectures. The formation process of the hierarchical SrF2microspheres and luminescence properties of SrF2:Ln3+(Ln = Ce, Tb, Yb, Er) microspheres have been investigated in detail. It is found that reaction time and trisodium citrate play a key role in forming the hierarchical microspheres. In addition, the lanthanide ions (Ln3+)-doped SrF2hierarchical microspheres show strong green (Ln3+= Ce3+, Tb3+) photoluminescence with 45% quantum efficiency and cathodoluminescence centered at 542 nm corresponding to the 5D4→ 7F5transition of Tb3+under excitation of ultraviolet light and low-voltage electron beam, respectively. In addition, SrF2:Yb3+,Er3+hierarchical microspheres show bright yellow upconversion emission under 980 nm laser diode excitation. The as-synthesized SrF2:Ln3+luminescent microspheres might find some potential applications in areas of photoluminescence and field emission displays.

The in situ photopolymerization method was applied to synthesize bulk nanocomposites consisting of hydrophobic NaYF4:Yb3+, Er3+(Tm3+) nanoparticles as the filler and poly(methyl methacrylate) (PMMA) as the host material. The oleic acid stabilized NaYF4:Yb3+, Er3+(Tm3+) nanoparticles and NaYF4:Yb3+, Er3+(Tm3+)/PMMA nanocomposites have been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), the thermogravimetric analysis (TGA), flexural tests, UV/vis transmission spectra, upconversion photoluminescence spectra, and luminescence decays. The well-crystallized NaYF4:Yb3+, Er3+(Tm3+) nanoparticles are spherical with a mean diameter of 40 nm. The obtained solid NaYF4:Yb3+, Er3+(Tm3+)/PMMA nanocomposites have similar mechanical properties to that of pure polymer. NaYF4:Yb3+, Er3+/PMMA and NaYF4:Yb3+, Tm3+/PMMA nanocomposites are transparent in the visible spectral region and exhibit strong green and blue upconversion photoluminescence upon 980 nm laser excitation due to the integration of luminescent NaYF4:Yb3+, Er3+and NaYF4:Yb3+, Tm3+nanoparticles, respectively.

nanofibers and nanobelts have been prepared by a combination method of the sol-gel process and electrospinning. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy, photoluminescence, and low voltage cathodoluminescence as well as kinetic decays were used to characterize the resulting samples. The results of XRD and FTIR indicate that the samples have crystallized at with the monoclinic structure. The SEM and TEM results indicate that the as-formed precursor fibers and belts are uniform and that the as-prepared nanofibers and nanobelts consist of nanoparticles. phosphors show their strong characteristic emission under UV excitation (353 nm) and low voltage electron-beam excitation (3 kV), making the materials have potential applications in fluorescent lamps and field-emission displays.

Luminescent, mesoporous, and bioactive europium‐doped hydroxyapatite (HAp:Eu3+) nanofibers and microbelts have been prepared by a combination of sol–gel and electrospinning processes with a cationic surfactant as template. The obtained multifunctional hydroxyapatite nanofibers and microbelts, which have mesoporous structure and red luminescence, were tested as drug carriers by investigating their drug‐storage/release properties with ibuprofen (IBU) as model drug. X‐ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution (HR) TEM, FTIR spectroscopy, N2adsorption/desorption, photoluminescence (PL) spectra, and UV/Vis spectroscopy were used to characterize the structural, morphological, textural, and optical properties of the resulting samples. The results reveal that the multifunctional hydroxyapatites exhibit irregular mesostructure, and have fiberlike and beltlike morphologies with sizes of several hundred nanometers in width and several millimeters in length. The IBU‐loaded HAp:Eu3+system shows red luminescence of Eu3+(5D0–7F0,1,2) under UV irradiation and controlled release of IBU. In addition, the emission intensity of Eu3+in the drug carrier system varies with the released amount of IBU, and thus drug release can be easily tracked and monitored by the change in luminescence intensity.

Light fantastic!Lu2O3:Yb3+/Er3+/Tm3+nanocrystals with controllable red, green, blue (RGB) and bright white upconversion luminescence by a single laser excitation of 980 nm have been successfully synthesized (see picture). Due to abundant UC PL colors, it can potentially be used as fluorophores in the field of color displays, back light, UC lasers, photonics, and biomedicine.

β-NaYF4hexagonal microprisms and microrods with different aspect ratios have been prepared via a simple hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The influences of reaction temperature and the molar ratio of NaF to Y3+on the crystal phases and shapes of final products have been studied in detail. The aspect ratios of products increase gradually with the increase of reaction temperature and NaF/Y3+molar ratio. The growth mechanisms of crystals prepared under the different conditions are presented systematically. More importantly, the systematical investigation on the luminescence properties of β-NaYF4:xEu3+(x= 0.5, 1, 2, 3, 5, and 10 mol %) with hexagonally microprismatic morphology shows the characteristic emissions of Eu3+(5DJ−7FJ′, J, J′ = 0, 1, 2, 3). Under the excitation of single wavelength light of 397 nm, the luminescence colors of the corresponding products can be tuned feasibly from bluish white to yellow to red by changing the doping concentration of Eu3+. This merit of multicolor emissions in the visible region endows this kind of materials with potential application in the field of light display systems, lasers, and optoelectronic devices.

Magnetically functionalized mesoporous silica spheres with different size (average diameter, A.D.) from 150 nm to 2 μm and pore size distribution were synthesized by generating magnetic FexOynanoparticles onto the mesoporous silica hosts using the sol−gel method. The X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), N2adsorption/desorption results show that these composites conserved regular sphere morphology and ordered mesoporous structure after the formation of FexOynanoparticles. XRD and X-ray photoelectron spectroscopy (XPS) analysis confirmed that the FexOygenerated in these mesoporous silica hosts is mainly composed of γ-Fe2O3. Magnetic measurements reveal that these composites with different γ-Fe2O3loading amounts possess super-paramagnetic properties at 300 K, and the saturation magnetization increases with increasing Fe ratio loaded. The ibuprofen-containing spheres were then coated with biodegradable poly(DL-lactide-co-glycolide) (PLGA) by the S/O/W single-emulsion method. The PLGA hybrid magnetic spheres realize a reduced initial burst with a sustained release stage lasting for 20 days. These composites with or without the PLGA can be used as potential vectors for drug targeting and controlled-release systems.

Hollow spherical Y2O3and YBO3have been prepared by a facile template-directed strategy using phenol-formaldehyde (PF) resin spheres as templates. The PF@Y(OH)CO3precursor can be fabricated by a simple precipitation route. The Y2O3hollow spheres are obtained via a direct annealing process, and the hollow spherical YBO3are fabricated via a hydrothermal route followed by an annealing process at the expense of the same PF@Y(OH)CO3precursor. The whole synthesis procedure is performed in aqueous solution without any surfactant or catalyst. Moreover, YVO4quasi-octahedral microcrystals with spherical holes are obtained. The formation mechanisms of the yttrium compounds with different morphologies have been discussed. By incorporating proper rare earth activator ions into the Y2O3, YBO3, and YVO4hosts, the as-synthesized luminescent materials can exhibit eminent performances with both down-conversion and up-conversion luminescence. Furthermore, the as-fabricated light-emitting diode (LED) devices can emit dazzling characteristic emission light, which reveals that the phosphors have application potential in lighting and displays. This simple synthesis strategy may provide a new idea for the fabrication of inorganic compounds with perfect hollow structures and excellent properties.

Many efforts have been devoted to exploring novel luminescent materials that not contain expensive or toxic elements, or do not need a mercury vapor plasma source. In this paper, BPO4and Li+-doped BPO4powder samples were prepared by the Pechini-type sol−gel (PSG) process. The structure and optical properties of the resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence (PL) excitation and emission spectra, kinetic decay, and X-ray photoelectron spectra (XPS), respectively. It was found that PSG -derived Li+-doped BPO4annealed at 960 °C exhibited bright bluish-white emission centered at 416 nm. The luminescence decay curves analysis indicates that each sample has two kinds of lifetimes (5.9 ns and 0.529 ms) and two types of kinetic decay behaviors which can be fitted into a single-exponential function and a double-exponential function, respectively. This can be attributed to two kinds of emission centers in samples. The luminescent mechanisms of the samples are discussed in detail.

Three-dimensional flowerlike Lu 2O 3and Lu 2O 3:Ln 3+(Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures have been successfully synthesized via ethylene glycol (EG)-mediated hydrothermal method followed by a subsequent heat treatment process. X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectra, thermogravimetric and differential thermal analysis, elemental analysis, inductively coupled plasma atomic absorption spectrometric analysis, ion chromatogram analysis, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, photoluminescence spectra as well kinetic decays, and cathodoluminescence spectra were used to characterize the samples. Hydrothermal temperature, EG, and CH 3COONa play critical roles in the formation of the lutetium oxide precursor microflowers. The reaction mechanism and the self-assembly evolution process have been proposed. The as-formed lutetium oxide precursor could transform to Lu 2O 3with their original flowerlike morphology and slight shrinkage in the size after postannealing process. The as-obtained flowerlike Lu 2O 3:Ln 3+samples show strong light emission with different colors corresponding to different Ln 3+ions under ultraviolet−visible light excitation and low-voltage electron beams excitation, which have potential applications in fluorescent lamps and field emission displays.

Rhombohedral‐calcite and hexagonal‐vaterite types of LuBO3:Eu3+microparticles with various complex self‐assembled 3D architectures have been prepared selectively by an efficient surfactant‐ and template‐free hydrothermal process for the first time. X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectrometry, transmission electron microscopy, high‐resolution transmission electron microscopy, selected area electron diffraction, photoluminescence, and cathodoluminescence spectra as well as kinetic decays were used to characterize the samples. The pH, temperature, concentration, solvent, and reaction time have a crucial influence on the phase formation, shape evolution, and microstructure. The reaction mechanism is considered as a dissolution/precipitation process; it is proposed that the self‐assembly evolution occurs by homocentric layer‐by‐layer growth. Under UV excitation and low‐voltage electron beam excitation, calcite‐type LuBO3:Eu3+particles show a strong orange emission corresponding to the 5D0→7F1transition of Eu3+whereas vaterite‐type LuBO3:Eu3+particles exhibit a strong red emission with much higher R/O values (that is, chromatically redder fluorescence than that of crystals grown from a direct solid‐state reaction). The tunable luminescent properties have potential applications in fluorescent lamps and field emission displays.

In this paper, BPO4-xSiO2(x:  SiO2/BPO4molar ratio, 0−70%) and BPO4-xAl2O3(x:  Al2O3/BPO4molar ratio, 0−20%) powder samples were prepared by the Pechini-type sol−gel (PSG) process using glycerol and poly(ethylene glycol) as additives. The structure and optical properties of the resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), diffuse reflection spectra, photoluminescence (PL) excitation and emission spectra, kinetic decay, and X-ray photoelectron spectra (XPS), respectively. It was found that the Pechini-type sol−gel-derived BPO4-xSiO2annealed at 1000 °C and BPO4-xAl2O3annealed at 960 °C exhibited bright bluish-white emissions centered at 428 and 413 nm, respectively. The luminescence decay curve analysis indicates that each sample has two kinds of lifetimes (more than 0.4 ms and less than 10 ns) and two types of kinetic decay behaviors, which can be fitted into a double-exponential function and a single-exponential function, respectively. This can be attributed to two kinds of emission centers in samples. The luminescent mechanisms of PSG-derived BPO4-xSiO2and BPO4-xAl2O3samples were discussed in detail.

LaF3, CeF3, CeF3:Tb3, and CeF3:Tb3LaF3(core−shell) 2D nanoplates have been successfully synthesized by a facile and effective hydrothermal process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The experimental results indicate that the organic additive, trisodium citrate (Cit3-), as a shape modifier has the dynamic effect by adjusting the growth rate of different crystal facets, resulting in forming the anisotropic geometries of the final products. The possible formation mechanisms for different products have been presented. The CeF3, CeF3:Tb3, and CeF3:Tb3LaF3(core/shell) nanoplates show characteristic emission of Ce3(5d−4f) and Tb3(f−f), respectively. By coating the LaF3shell on the surface of the CeF3:Tb3core, the distance between the luminescent lanthanide ions is increased and the surface quenchers are decreased, thus reducing the nonradiative pathways. The luminescent intensity and lifetime of the CeF3:Tb3LaF3core/shell nanoplates are enhanced with respect to the bare CeF3:Tb3nanoplates.

Nearly monodisperse and well-defined one-dimensional (1D) Gd2O3:Eu3nanorods and microrods were successfully prepared through a large-scale and facile hydrothermal method followed by a subsequent heat treatment process, without using any catalyst or template. X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA−DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence (PL) and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The size of the Gd2O3:Eu3rods could be modulated from micro- to nanoscale with the increase of pH value using ammonia solution. The as-formed product via the hydrothermal process, Gd(OH)3:Eu3, could transform to cubic Gd2O3:Eu3with the same morphology and a slight shrinking in size after a postannealing process. The formation mechanism for the Gd(OH)3rods has been proposed. Both the Gd2O3:Eu3nanorods and microrods exhibit the same strong red emission corresponding to 5D0→ 7F2transition (610 nm) of Eu3under UV light excitation (257 nm) and low-voltage electron beam excitation (1−5 kV), which have potential applications in fluorescent lamps and field emission displays.

Nanocrystalline ZrO2fine powders were prepared via the Pechini-type sol−gel process followed by annealing from 500 to 1000 °C. The obtained ZrO2samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR), and photoluminescence spectra (PL), respectively. The phase transition process from tetragonal (T) to monoclinic (M) was observed for the nanocrystalline ZrO2powders in the annealing process, accompanied by the change of their photoluminescence properties. The 500 °C annealed ZrO2powder with tetragonal structure shows an intense whitish blue emission (max425 nm) with a wide range of excitation (230−400 nm). This emission decreased in intensity after being annealed at 600 °C (T M-ZrO2) and disappeared at 700 (T M-ZrO2), 800 (T M-ZrO2), and 900 °C (M-ZrO2). After further annealing at 1000 °C (M-ZrO2), a strong blue-green emission appeared again (max470 nm). Based on spectral analysis and EPR results, the whitish blue emission (425 nm) and blue-green emission (470 nm) can be ascribed to interstitial carbon impurities (Ci) in the tetragonal ZrO2and oxygen vacancies (VO) in the monoclinic ZrO2, respectively.

A novel red emitting phosphor, Eu3+-doped Ca2GeO4was prepared through the solid state reaction. We also replace Ca2+with Mg2+and Ba2+ions and add Li+, Al3+ions as charge compensators in the Ca2GeO4host to improve the luminescence properties of Ca2GeO4:Eu3+phosphor. XRD, FE-SEM, photoluminescence and cathodoluminescence spectra were utilized to characterize the samples. XRD reveals that pure Ca2GeO4phase can be obtained at 1250°C and all the above cation substitutions can be achieved in a certain concentration range except for Ba2+ion. FE-SEM images indicate that the Ca1.99GeO4:0.01Eu3+sample and its substitutions consist of aggregated particles with size ranging from 0.5 to 2 μm, and Ba1.99GeO4:0.01Eu3+sample is composed of uniform and spindle-like structures with the size ranging from 300 to 500 nm. Under the excitation of ultraviolet light and low-voltage electron beams, the Ca2GeO4:Eu3+phosphor shows the characteristic emissions of Eu3+(5D0–7F2at 613 nm, red). The optimum concentration for the luminescence Eu3+is determined to be 0.01 in Ca2−xGeO4:xEu3+phosphor. The luminescent intensity can be improved by co-doping the Mg2+ions and charge compensators (Li+and Al3+) to partially substitute of Ca2+ions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Gd2MoO6:Eu3+nanofibers and nanobelts have been prepared by a combination method of the sol–gel process and electrospinning. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy, photoluminescence, and low voltage cathodoluminescence as well as kinetic decays were used to characterize the resulting samples. The results of XRD and FTIR indicate that the Gd2MoO6:Eu3+samples have crystallized at 600°Cwith the monoclinic (α)structure. The SEM and TEM results indicate that the as-formed precursor fibers and belts are uniform and that the as-prepared nanofibers and nanobelts consist of nanoparticles. Gd2MoO6:Eu3+phosphors show their strong characteristic emission under UV excitation (353 nm) and low voltage electron-beam excitation (3 kV), making the materials have potential applications in fluorescent lamps and field-emission displays.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.