YF3 Nanoparticles Research Articles

Innovative synthesis of YF3‐TiO2 acid‐base catalysts with high surface area by embedding yttrium trifluoride nanoparticles in TiO2 metallogel

Combining a water‐tolerant oxide such as TiO2 with yttrium fluoride is expected to provide catalysts with enhanced acid‐base properties for catalytic applications in water. We present here a new strategy of incorporating pre‐formed YF3 nanoparticles (NPs) in a TiO2‐based metallogel, followed by its soft drying at room temperature to produce YF3‐TiO2 xerogel with high surface area. The as‐synthesized YF3‐TiO2 materials were calcinated at 300 and 400 and characterized by X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), 19F NMR and N2 physisorption, calorimetry of NH3 adsorption, and FT‐IR of pyridine adsorption. These studies indicate that the fluorine is present under a stable form of YF3 for the catalysts calcined at 300 °C. The acid‐base properties of these YF3‐TiO2 catalysts were investigated in a model reaction, i.e., dihydroxyacetone (DHA) conversion in water, and compared with the blank TiO2 and YF3 NPs alone. The incorporation of YF3 in the TiO2 matrix leads to enhanced initial rate of DHA dehydration into pyruvaldehyde, which is slowly converted to lactic acid as the reaction progresses. This suggests that the Brønsted acidity was boosted by the presence of YF3 species via water adsorption in a dissociative form.

Pr3+-doped YF3, LaF3, and GdF3 nanoparticles: comparative crystallographic, Raman, optical, and photoluminescence properties

Pr3+-doped YF3, LaF3, and GdF3 nanoparticles: comparative crystallographic, Raman, optical, and photoluminescence properties

Eu3+-ion doped LnF3 NPs: Comparative study of the crystallographic, and photophysical properties

The thermal co-precipitation approach was employed for the synthesis of the Eu3+-ion doped YF3, LaF3, and GdF3 nanoparticles (NPs) and compared their photophysical properties. Ammonium fluorite was used as a fluorine source for the synthesis of metal fluorides at lower temperatures. Luminescent lanthanide fluoride (LnF3) NPs were characterized by different techniques containing X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), FT-Raman, UV/Visible absorption spectra, and photoluminescence spectroscopic procedures to investigate the crystal structural, thermal, Raman effect, surface, optical, and luminescent properties. XRD study shows two types of crystal phase orthorhombic in YF3:Eu & GdF3:Eu and hexagonal in LaF3:Eu NPs. TGA, FTIR, and absorption spectra studies show the exterior adsorbed –OH molecules, which assist in the development of colloidal solution in aqueous media. Raman vibrations were strongly affected which were correlated with the XRD reflection planes. In comparative photo-physical properties, the excitation and emission spectra exhibited remarkable intensities of the Eu3+-ion transitions. Similarly, the emission spectra of all three samples exhibited the highest emission efficiency of the magnetically-dipole(5D0→7F2) transition in comparison to the electric-dipole 5D0→7F1 transition, which reflected the transformation of the crystal symmetry. Comparative analysis was presented to investigate the role of the host lattice on crystallinity, thermal stability, and luminescent properties. These findings are highly fruitful in designing photonic-based applications including optical biosensors, fingermark detection, security systems, etc.

Nd3+, Yb3+:YF3 Optical Temperature Nanosensors Operating in the Biological Windows

This work is devoted to the study of thermometric performances of Nd3+ (0.1 or 0.5 mol.%), Yb3+ (X%):YF3 nanoparticles. Temperature sensitivity of spectral shape is related to the phonon-assisted nature of energy transfer (PAET) between Nd3+ and Yb3+). However, in the case of single-doped Nd3+ (0.1 or 0.5 mol.%):YF3 nanoparticles, luminescence decay time (LDT) of 4F3/2 level of Nd3+ in Nd3+ (0.5 mol.%):YF3 decreases with the temperature decrease. In turn, luminescence decay time in Nd3+ (0.1 mol.%):YF3 sample remains constant. It was proposed, that at 0.5 mol.% the cross-relaxation (CR) between Nd3+ ions takes place in contradistinction from 0.1 mol.% Nd3+ concentration. The decrease of LDT with temperature is explained by the decrease of distances between Nd3+ with temperature that leads to the increase of cross-relaxation efficiency. It was suggested, that the presence of both CR and PAET processes in the studied system (Nd3+ (0.5 mol.%), Yb3+ (X%):YF3) nanoparticles provides higher temperature sensitivity compared to the systems having one process (Nd3+ (0.1 mol.%), Yb3+ (X%):YF3). The experimental results confirmed this suggestion. The maximum relative temperature sensitivity was 0.9%·K-1 at 80 K.

Yttrium trifluoride doped polyacrylonitrile based carbon nanofibers as separator coating layer for high performance lithium-metal batteries

In this study, the yttrium trifluoride-doped polyacrylonitrile(PAN) based carbon nanofibers (YF3-PAN-CNFs) are successfully designed and prepared through the electro-blow spinning and carbonization strategies. And the YF3-PAN-CNFs acted as main materials of functional layer for modifying separator of lithium metal batteries are systematically studied and analyzed. The prepared CNFs have long-range ordered structures and high conductivity, which can extremely improve the transport of lithium ions and electrons during charge–discharge processes. The lithiophilic YF3 nanoparticles formed in the carbonization process can endow enough active sites to produce alloying reaction with Li, which makes the plating/stripping of Li more uniform. For the assembled Li||lithium iron phosphate (LiFePO4) battery, it still maintains a high specific discharge capacity of 137.1 mAh g−1 after 500 cycles at 0.5 C, which there is almost no specific discharge capacity degradation after long cycle. The modified separator for the Li||Li symmetric battery can effectively suppress the growth of lithium dendrites and improve cycle stability. Meanwhile, based on the strong chemical bonding between YF3 and lithium polysulfide combining the effectively physical confinement of the YF3-PAN-CNFs coating layer, the “shuttle effect” of lithium polysulfide also can be greatly suppressed. Thus the assembled Li||S battery using the separator has excellent electrochemical performance. Therefore, the YF3-PAN-CNFs modified separator will have a promising application prospect in lithium metal batteries even other high performance secondary batteries.

Ratiometric Upconversion Temperature Sensor Based on Cellulose Fibers Modified with Yttrium Fluoride Nanoparticles.

In this study, an optical thermometer based on regenerated cellulose fibers modified with YF3: 20% Yb3+, 2% Er3+ nanoparticles was developed. The presented sensor was fabricated by introducing YF3 nanoparticles into cellulose fibers during their formation by the so-called Lyocell process using N-methylmorpholine N-oxide as a direct solvent of cellulose. Under near-infrared excitation, the applied nanoparticles exhibited thermosensitive upconversion emission, which originated from the thermally coupled levels of Er3+ ions. The combination of cellulose fibers with upconversion nanoparticles resulted in a flexible thermometer that is resistant to environmental and electromagnetic interferences and allows precise and repeatable temperature measurements in the range of 298–362 K. The obtained fibers were used to produce a fabric that was successfully applied to determine human skin temperature, demonstrating its application potential in the field of wearable health monitoring devices and providing a promising alternative to thermometers based on conductive materials that are sensitive to electromagnetic fields.

YF3/CoF3 co-doped 1D carbon nanofibers with dual functions of lithium polysulfudes adsorption and efficient catalytic activity as a cathode for high-performance Li-S batteries

Lithium-sulfur (Li-S) batteries have attracted extensive attention in the field of energy storage due to their high energy density and low cost. However, conundrums such as severe polarization, poor cyclic performance originating from shuttle effect of lithium polysulfides and sluggish sulfur redox kinetics are stumbling blocks for their practical application. Herein, a novel sulfur cathode integrating sulfur and polyvinylpyrrolidone(PVP)-derived N-doped porous carbon nanofibers (PCNFs) with embedded CoF3 and YF3 nanoparticles are designed and prepared though the electrostatic blowing technology and carbonization process. The unique flexible PCNFs with embedded polar CoF3 and YF3 nanoparticles not only offer enough voids for volume expansion to maintain the structural stability during the electrochemical process, but also promote the physical encapsulation and chemical entrapment of all sulfur species. Moreover, the uniform distribution of YF3/CoF3 nanoparticles also can expose more binding active sites to lithium polysulfide and present more catalytic sites to the greatest extent. Therefore, the assembled cells with the prepared cathode exhibited stable performances with an outstanding initial capacity of 1055.2 mAh g−1 and an extended cycling stability of 0.029% per cycle during the 300 cycles at 0.5C. Even at a high sulfur loading of 2.1 mg cm−2, The YF3/CoF3 doped-PCNFs exhibited a high discharge specific capacity of 1038 mAh g−1, and the decay rate is also as low as 0.05% over 1000 cycles. This work shares a convenient and safe strategy for the synthesis of multi-dimension, dual-functional and stable superstructure electrode for advanced Li-S batteries.

Praseodymium doped YF3:Pr3+ nanoparticles as optical thermometer based on luminescence intensity ratio (LIR) – Studies in visible and NIR range

Luminescent YF3 nanoparticles doped with Pr3+ activator ion have been successfully synthesized via a facile hydrothermal approach for their application as a multi-range optical sensor of temperature. The product synthesized shows intense yellow luminescence at 457 nm laser excitation, and the emission spectra were recorded from 475 to 1650 nm, showing the presence of sharp emission peaks in the measured spectral range. The intensity of the observed emission bands typical of Pr3+ ion changes with temperature significantly. Hence, the intensity ratios of the thermalized emission bands were determined in the temperature range from 293 to 421 K, and they were calibrated for thermal sensing purposes. High relative sensitivity values, ranging from 0.6 to 1.2 %K−1, were found for the emission bands of the thermally-coupled 3P1 and 3P0 excited states located around 522–537, 586–603 and 700–723 nm. The temperature calibration based on the thermalized 3P1→3F4 and 3P0→3F4 bands located in the first biological optical window (650–950 nm), may be especially useful for potential biological applications.

Efficacy of Yttrium (III) Fluoride Nanoparticles in Orthodontic Bonding.

Our study evaluated the adhesion strength and antibacterial effect of a conventional orthodontic composite resin blended with yttrium fluoride (YF₃) nanoparticles. Yttrium fluoride nanoparticles (NP) were added to the conventional orthodontic composite resin (Transbond XT) at concentrations of 1%, 2%, and 3% (w/w), and the blended composite resins were labeled as NP1, NP2, and NP3, respectively. A total of 60 extracted human premolars was randomly allocated to four groups of 15 samples (n = 15). Orthodontic brackets were bonded using the conventional (control) and experimental composite resins (NP1, NP2, and NP3). The adhesion strengths of the composite resins were determined using a universal testing machine. The debonding sites were assessed and scored using the adhesive remnant index (ARI). The antibacterial effect of YF₃ nanoparticles against Streptococcus mutans was assessed by the viable cell counting method. For the same, 40 composite disc specimens were prepared using the control and experimental composite resins (n = 10). The data was analyzed by one-way ANOVA and Tukey's post hoc analysis. In all the tests, the significance level was determined to be 0.05. The highest adhesion strength values were found in the control group (11.61±0.23) and the lowest values were found in the NP3 group (10.49±0.17). A significant difference was observed between the control and experimental groups, NP2 and NP3 (P < 0.05). NP1 group showed insignificant (P = 0.388) adhesion strength values compared with the control group. There was no significant difference between the ARI scores of the conventional and experimental groups (P > 0.05). The highest colony forming units (CFU) were found in the control group (75.85±1.15) and the lowest CFU were found in the NP1 group (2.24±1.14). A significant difference between the mean CFU of the conventional and experimental composite groups was observed (P < 0.05). Despite higher antibacterial activity in the NP1 group compared with NP2 (P = 0.146) and NP3 (P = 0.117), the difference was not significant. Similarly, no significant difference was observed between NP2 and NP3 groups (P = 0.97). Our results suggested that yttrium fluoride nanoparticles, blended with a conventional resin at 1% concentration, demonstrated significant antibacterial effect and did not compromise adhesion strength.

Tunable Self-Assembly of YF3 Nanoparticles by Citrate-Mediated Ionic Bridges.

Ligand-to-surface interactions are critical factors in surface and interface chemistry to control the mechanisms governing nanostructured colloidal suspensions. In particular, molecules containing carboxylate moieties (such as citrate anions) have been extensively investigated to stabilize metal, metal oxide, and metal fluoride nanoparticles. Using YF3 nanoparticles as a model system, we show here the self-assembly of citrate-stabilized nanostructures (supraparticles) with a size tunable by temperature. Results from several experimental techniques and molecular dynamics simulations show that the self-assembly of nanoparticles into supraparticles is due to ionic bridges between different nanoparticles. These interactions were caused by cations (e.g., ammonium) strongly adsorbed onto the nanoparticle surface that also interact strongly with nonbonded citrate anions, creating ionic bridges in solution between nanoparticles. Experimentally, we observe self-assembly of nanoparticles into supraparticles at 25 and 100 °C. Interestingly, at high temperatures (100 °C), this citrate-bridge self-assembly mechanism is more efficient, giving rise to larger supraparticles. At low temperatures (5 °C), this mechanism is not observed, and nanoparticles remain stable. Molecular dynamics simulations show that the free energy of a single citrate bridge between nanoparticles in solution is much larger than the thermal energy and in fact is much larger than typical adsorption free energies of ions on colloids. Summarizing our experiments and simulations, we identify as key aspects of the self-assembly mechanism the requirement of NPs with a surface able to adsorb anions and cations and the presence of multidentate ions in solution. This indicates that this new ion-mediated self-assembly mechanism is not specific of YF3 and citrate anions, as supported by preliminary experimental results in other systems.

Upconverting luminescence based dual-modal temperature sensing for Yb3+/Er3+/Tm3+: YF3 nanocrystals embedded glass ceramic

Yb3+/Er3+/Tm3+ doped transparent glass ceramic containing orthorhombic YF3 nanoparticles was successfully synthesized by a melt-quenching method. After glass crystallization, tremendously enhanced (about 5000 times) upconversion luminescence, obvious Start-splitting of emission bands as well as long upconversion lifetimes of Er3+/Tm3+ confirmed the incorporation of lanthanide activators into precipitated YF3 crystalline environment with low phonon energy. Furthermore, temperature-dependent upconversion luminescence behaviors of glass ceramic were systematically investigated to explore its possible application as optical thermometric medium. Impressively, both fluorescence intensity ratio of Er3+: 2H11/2→4I15/2 transition to Er3+: 4S3/2→4I15/2 one and fluorescence intensity ratio of Tm3+: 3F2,3→3H6 transition to the combined Tm3+: 1G4→3F4/Er3+: 4F9/2→4I15/2 ones were demonstrated to be applicable as temperature probes, enabling dual-modal temperature sensing. Finally, the thermal effect induced by the irradiation of 980nm laser was found to be negligible in the glass ceramic sample, being beneficial to gain intense and precise probing signal and detect temperature accurately.

The Synthesis of a Core-Shell Photocatalyst Material YF3:Ho3+@TiO2 and Investigation of Its Photocatalytic Properties

In this paper, YF3:Ho3+@TiO2 core-shell nanomaterials were prepared by hydrolysis of tetra-n-butyl titanate (TBOT) using polyvinylpyrrolidone K-30 (PVP) as the coupling agent. Characterization methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) under TEM, X-ray photoelectron spectroscopy (XPS), fluorescence spectrometry, ultraviolet-visible diffuse reflectance spectroscopy, and electron spin resonance (ESR) were used to characterize the properties and working mechanism of the prepared photocatalyst material. They indicated that the core phase YF3 nanoparticles were successfully coated with a TiO2 shell and the length of the composite was roughly 100 nm. The Ho3+ single-doped YF3:Ho3+@TiO2 displayed strong visible absorption peaks with wavelengths of 450, 537, and 644 nm, respectively. By selecting these three peaks as excitation wavelengths, we could observe 288 nm (5D4→5I8) ultraviolet emission, which confirmed that there was indeed an energy transfer from YF3:Ho3+ to anatase TiO2. In addition, this paper investigated the influences of different TBOT dosages on photocatalysis performance of the as-prepared photocatalyst material. Results showed that the YF3:Ho3+@TiO2 core-shell nanomaterial was an advanced visible-light-driven catalyst, which decomposed approximately 67% of rhodamine b (RhB) and 34.6% of phenol after 10 h of photocatalysis reaction. Compared with the blank experiment, the photocatalysis efficiency was significantly improved. Finally, the visible-light-responsive photocatalytic mechanism of YF3:Ho3+@TiO2 core-shell materials and the influencing factors of photocatalytic degradation were investigated to study the apparent kinetics, which provides a theoretical basis for improving the structural design and functions of this new type of catalytic material.

A highly sensitive upconverting nano-glass-ceramic-based optical thermometer

Yb/Tm: YF3 nanoparticles embedded transparent bulk glass ceramic was successfully prepared to explore its possible application in optical temperature sensors. Specifically, owing to the competition of electron population in the thermally coupled Tm3+3F2,3 and 3H4 excited states, two upconversion emission bands corresponding to Tm3+: 3F2,3 → 3H6 transition and 1G4→3F4 one exhibited opposite temperature-dependent behaviors, which resulted in monotonous enhancement of the related fluorescence intensity ratio with increase of temperature. As a consequence, Tm3+ activators in the present YF3 glass ceramic had advantages of a high sensitivity of 1.84% per K, an avoidable spectral overlapping and a negligible thermal effect for accurate temperature detecting.

Solvothermal synthesis and upconversion properties of YF3:Ln (Ln = Yb/Er,Yb/Tm,Yb/Ho) nanoparticles.

YF3 nanoparticles with different morphology, dimension, and dispersity have been synthesized through a simple solvothermal method by using n-octanol and n-octylamine as a mixed solvent and lanthanide acetylacetonate as the RE3+ source. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrum (EDS) and up-conversion (UC) photoluminescence spectra were used to characterize the samples. The results reveal that the morphology and dimension of the as-prepared nanoparticles can be regulated by adjusting n-octanol/ n-octylamine volume ratio in the initial system. Besides, by doping with different rare-earth elements (Yb/Er, Yb/Tm, Yb/Ho), the as-prepared YF3 samples can emit characteristic green, blue, and yellow light under 980 nm laser excitation. Additionally, when being co-doped with the activator ion-pairs Tm/Er and Tm/Ho, the color of the emission light can be further modified by adjusting the Yb3+ ion content.

Comprehensive Solid-State Characterization of Rare Earth Fluoride Nanoparticles

The combination of multinuclear solid-state NMR spectroscopy and powder X-ray diffraction has been applied to characterize the octahedron-shaped crystalline nanoparticle products resulting from an inverse micelle synthesis. Rietveld refinements of the powder X-ray diffraction data from the nanoparticles revealed their general formula to be (H3O)Y3F10·xH2O. 1H magic-angle spinning (MAS) NMR experiments provided information on sample purity and served as an excellent probe of the zeolithic incorporation of atmospheric water. 19F MAS NMR experiments on a series of monodisperse nanoparticle samples of various sizes yielded spectra featuring three unique 19F resonances arising from three different fluorine sites within the (H3O)Y3F10·xH2O crystal structure. Partial removal of zeolithic water from the internal cavities and tunnels of the nanoparticles led to changes in the integrated peak intensities in the 19F MAS NMR spectra; the origin of this behavior is discussed in terms of 19F longitudinal relaxation. 19F–89Y variable-amplitude cross-polarization (VACP) NMR experiments on both stationary samples and samples under MAS conditions indicated that two distinct yttrium environments are present, and on the basis of the relative peak intensities, the population of one of the two sites is closely linked to the nanoparticle size. Both 19F MAS and 19F–89Y VACP/MAS experiments indicated small amounts of an impurity present in certain nanoparticles; these are postulated to be spherical amorphous YF3 nanoparticles. We discuss the importance of probing molecular-level structure in addition to microscopic structure and how the combination of these characterization methods is crucial for understanding nanoparticle design, synthesis, and application.

Synthesis of ligand-functionalized water-soluble [18F]YF3 nanoparticles for PET imaging

We report a simple, efficient synthesis of novel (18)F-labeled imaging agents based on YF3 nanoparticles. Targeting ligands and antitumor drug molecules can be introduced onto the YF3 nanoparticles in a one-pot synthesis. The (18)F-labeling reaction proceeds in aqueous solutions at room temperature with excellent radiolabeling yields (>80%) in a very short time (5-10 min). (18)F-labeled YF3 nanoparticles displayed high stability in mouse and human serum, and their application for mapping lymph nodes in live rats after local injection has also been demonstrated.

Spectroscopic properties and upconversion in Pr3+:YF3 nanoparticles

The synthesis and spectroscopic investigation of Pr(3+):YF(3) nanoparticles with nominal concentration between 0.05% and 5 at% Pr(3+) are reported. Pr(3+) emission in the visible range of the spectrum is investigated at room temperature and at 10 K as well as time resolved spectroscopy as a function of Pr(3+) concentration. The upconverted emission from the orange to the blue region is observed and the time-resolved spectroscopy of the visible emissions is discussed as a function of the doping level. A careful analysis of the decays permits identification of the main energy-transfer mechanisms that determine the population of the excited levels at various times during the decay.

Luminescence properties of rare earth doped YF3 and LuF3 nanoparticles

Eu 3 + doped and Yb3+/Ho3+ codoped LuF3 and YF3 nanoparticles with a size distribution of 200–300 nm have been prepared by adopting a combustion-fluorization method. The luminescence spectra of Eu3+ and Ho3+ ions in the YF3 and LuF3 nanoparticles have been investigated through comparison. It is found that the Eu3+ and Ho3+ ions in the two hosts show different luminescence properties although the sites occupied by the rare earth (RE) ions in the LuF3 and YF3 hosts are of the same symmetry. The different luminescence properties may be ascribed to the difference in the RE-F bond nature in the YF3 and LuF3 hosts.

Synthesis and Luminescence Properties of Lanthanide (III)-Doped YF3 Nanoparticles

Synthesis process and luminescence properties of trivalent lanthanide ions (Ln3+) doped YF3 nanoparticles have been investigated. To synthesis Ln(3+)-doped YF3 nanoparticles, the mixture of (YCl3 x nH2O + LnCl3 x nH2O), and NH4F was hydrothermal treated at 180 degrees C in a Teflon-liner auto-clave or heated at higher temperatures (400 degrees C - 600 degrees C) in a stove. The XRD patterns showed that the Ln(3+)-doped orthorhombic YF3 nanoparticles with no second phase have been prepared. The solid solution Y(1-x)Eu(x)F3 (x = 0 - 0.4) nanoparticles have been synthesized. The luminescence concentration quenching resulted from resonance energy transfer between neighboring Eu3+ ions occurred at higher Eu3+ concentrations (30 mol%). The upconversion luminescence of Er(3+)-Yb3+ codoped YF3 nanoparticles under 980 nm excitation has also been observed. With increase of heated temperature, the size of the Er(3+)-Yb3+ codoped YF3 nanoparticles increased gradually, and upconversion luminescence intensity increased significantly.

Down/Up Conversion in Ln3+-Doped YF3 Nanocrystals

Nanocrystalline Ln3+-doped YF3 phosphors have been synthesized via a facile sonochemistry-assisted hydrothermal route. YF3 nanoparticles are demonstrated to be a good host material for different lanthanides. Varying the dopants leads to different optical properties. In particular, the feasibility of inducing red, green, and especially blue emission in the Yb3+/Er3+ co-doped YF3 sample by up-conversion excitation in the near-infrared region is demonstrated. Such unusually strong 411 nm blue up-conversion emission has seldom been reported in other Yb3+/Er3+-doped systems. The up-conversion mechanisms have been analyzed.