Doping Of Y3 Research Articles

Broad spectral response of Y-NaBi(MoO4)2@NaYF4:Yb, Tm photocatalysts for efficient degradation of ciprofloxacin: Upconversion mechanism and theoretical calculations

In this work, a novel Y-NaBi(MoO4)2@NaYF4:Yb, Tm composite was successfully synthesized for the first time by hydrothermal method. The lamellar Y-NaBi(MoO4)2 was dispersed on the surface of the hexagonal prism NaYF4:Yb, Tm without aggregation. The composite achieved a broad spectral response. The NaYF4:Yb, Tm absorbed near-infrared light and emitted ultraviolet and visible light by the energy transfer upconversion process. The emitted light was reabsorbed by Y-NaBi(MoO4)2 through the fluorescence resonance energy transfer process. Moreover, the doping of Y3+ ions enhanced the light response capability of the composite. The experimental results revealed that the photocatalytic degradation efficiency of ciprofloxacin (CIP) reached 96.2 % after 180 min of illumination under simulated sunlight. Meanwhile, the degradation pathways and attack sites of CIP were intensively investigated by liquid chromatography-mass spectrometry analysis and density functional theory theoretical calculations. The upconversion process, the separation of photogenerated carriers and rare earth metal ion doping all contributed to the high effective photodegradation. This work provided a new strategy for effective utilization of solar energy for the degradation of emerging pollutants to mitigate environmental pollution.

A novel and simple approach of rare earth ions (Y3+ and La3+) decorated nano calcium carbonate/ polyethylene glycol for photocatalytic degradation of organic pollutants in wastewater

Pristine and rare earth ions (Y3+ and La3+) decorated rhombohedral nano CaCO3/PEG were extracted from natural dolomite rock using a novel green route biomimetic synthesis. XRD analysis confirmed the crystal phase and doping of Y3+ and La3+ in the CaCO3/PEG. The FTIR analysis confirmed the presence of various functional groups in the synthesized nanoparticles. The obtained products exhibited good thermal stability at the temperatures up to 844 °C. The absorption and emission peaks were blue-shifted due to the impact of the doping ion concentration. The surface chemical compositions were analyzed using XPS. The direct and indirect bandgap energies of nCY1 (0.02 M Y3+: CaCO3/PEG) and nCL1 (0.02 M La3+: CaCO3/PEG) were 3.95, 3.27 eV (direct bandgap) and 2.52, 2.09 eV (indirect bandgap) respectively. The measured fluorescence quantum yields of nCY1 and nCL1 were 22% and 26%, respectively. FESEM with EDX mapping and HR-TEM with SAED analysis was used to determine the morphology, elemental mapping, and crystalline behavior. The photocatalytic activity of prepared samples were performed against methylene blue under UV irradiation. Based on photocatalytic results, nCL1 showed extremely high photocatalytic activity (92%). The effects of the scavenging agents were investigated using superoxide radicals, photogenerated holes, electrons, and OH radicals. Hence, the prepared samples could be an effective catalysts for significant environmental issues. This is the first study for preparing Y3+ and La3+ doped CaCO3/PEG nanoparticles from natural dolomite rock using a low-cost and nontoxic biomimetic method to get enhanced photodegradation efficiency.

Effect of rare earth ion on fluorescent properties of Eu(TTA)3phen/PMMA temperature sensitive paint

The temperature sensitive paint (TSP) technology is widely used in the temperature distribution measurement of large area solid field, especially for the in-depth research in the mechanical behavior of complex flow gas around the aircraft, because of its advantages of non-contact, full-field measurement, easy manufacture and use. In this work, we synthesized the rare earth ion(Y3+, Er3+) doped Eu(TTA)3phen/PMMA temperature sensitive paint respectively based on the probe molecules of the rare earth ion (Y3+, Er3+) doped Eu(TTA)3phen and polymethyl methacrylate(PMMA). The structure of probe molecules and the fluorescent properties of TSP were also studied. The result show that the optimal ratio of Eu3+:Y3+ (or Er3+) is 0.5:0.5, rare earth ions are coordinated with ligands and the doping of Y3+ and Er3+ do not affect the structure of Eu(TTA)3phen. Y3+ and Er3+ have gain effect on the fluorescent emission of Eu(TTA)3phen/PMMA and the strongest fluorescent intensity (616 nm) is decreased with the increasing of temperature, which show that the Y3+ and Er3+ doped Eu (TTA)3phen/PMMA have temperature quenching properties in the temperature range of 20–80 °C. What’s more, the doping of Y3+ and Er3+ can improve the change rate of the fluorescent intensity and the temperature measurement sensitivity.

Synergetic tuning of photocatalytic activity and photostability of Ag3PO4 via yttrium doping, carbon quantum dots and BiVO4 for atenolol degradation

In this study, Y-doped Ag3PO4, carbon quantum dots (CQDs), BiVO4 were used to synthesize Z-scheme Y-Ag3PO4/CQDs/BiVO4. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) and UV–vis diffuse reflectance spectra (DRS) were employed to probe into the crystalline structure, morphology, optical property and chemical composition of Y-Ag3PO4/CQDs/BiVO4. The kinetic constant of the prepared Y-Ag3PO4/CQDs/BiVO4 was approximately 2.8 times that of pristine Ag3PO4 for atenolol degradation. The degradation of atenolol mainly depended on the excited holes, •OH and •O2−. The photocatalysis mechanism of Y-Ag3PO4/CQDs/BiVO4 conforms to the Z-scheme mechanism deduced by reactive species trapping experiment, electron spin resonance (ESR) and photoelectrochemical measurement (photocurrent response and EIS). The introduction of yttrium, CQDs and BiVO4 significantly promoted the photogenerated carriers separation of Ag3PO4 and inhibited the photogenerated electron-holes pairs recombination of Ag3PO4 during the degradation of atenolol. Oxygen defects caused by the doping of Y3+ into Ag3PO4 were the centers of capture of photogenerated electrons to generate •O2−, inhibiting the recombination of photogenerated electron-holes pairs and the photocorrosion of Ag3PO4.

Effects of La3+ and Y3+ doping on spatial homogeneity of Ho3+ ions in high silica glass

In this work, we have investigated the influence of La3+ and Y3+ doping on the spatial homogeneity of Ho3+ ions in high silica glasses via structural and spectroscopic analyses. It is found that both of La3+ and Y3+ doping could lead to depolymerization of the glass network. Under the same doping concentration, Y3+ gives rise to a larger silicate connectivity than La3+. The spinning sideband patterns of the 27Al NMR spectra indicate that the population of Ho3+ ions in the vicinity of Al3+ decreases with the increase in the concentration of La3+ or Y3+. In comparison to La3+, the doping of Y3+ more favors Ho3+ ions to be populated around Al3+ in the glass network. The fluorescence centered at ~2 μm from Ho3+ ions exhibits an increase tendency when increasing the concentration of La3+ or Y3+. The results indicate that the doping of La3+ or Y3+ ions into high silica glasses can improve the spatial distribution homogeneity of Ho3+ ions and La3+ plays a more positive role than Y3+.

Influence of yttrium doping on the photocatalytic activity of bismuth oxybromide for ciprofloxacin degradation using indoor fluorescent light illumination

In this work, a series of Y-doped BiOBr photocatalysts with different yttrium contents were successfully synthesized through a facile ethylene glycol-assisted chemical precipitation method for the first time. The as-synthesized photocatalysts were characterized using N2 physical adsorption, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope accompanied with an energy-dispersive X-ray spectroscopy (FESEM/EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), photoluminescence (PL) and UV–Vis diffuse reflectance spectra (UV–Vis/DRS). Doping of Y3+ ion had no obvious effect on the structure and morphology of BiOBr, however the BET surface area was greatly improved. The photocatalytic degradation of ciprofloxacin under indoor fluorescent light illumination showed that doping of Y3+ ion could bring about a significant increase in the photocatalytic activity. Among the doped samples, the 3%Y–BiOBr showed the highest photocatalytic activity for 20 ppm ciprofloxacin with degradation efficiency of 87.6% in just 60 min as compared to pristine BiOBr which had the degradation efficiency of 71.7%. Such enhanced photocatalytic activity could be attributed to the efficient separation of photogenerated electron–hole pairs, increased optical absorption and high surface area. A possible mechanism for the photocatalytic reaction has been proposed.

Effect of Y3+ ion doping on the microstructure, transmittance and thermal properties of CaF2 transparent ceramics

This study aims to investigate the role of Y3+ ion on microstructure, optical transmittance, and thermal properties of CaF2 transparent ceramics. Series of nanosized CaF2 powders doped with different concentration of Y3+ ion were synthesized by direct precipitation method. XRD, FSEM and TEM results demonstrated that the CaF2 nanoparticles could be tuned in size through doping of Y3+ ion. Corresponding CaF2 transparent ceramics were fabricated by hot-pressed (HP) method. Compared with the undoped CaF2 sample, the transmittance of the CaF2 ceramics improved dramatically after doping with Y3+ ions and reached above 80% at the wavelength of 1200 nm. The effects of Y3+ ion on the microstructure and thermal properties of CaF2 transparent ceramics were also investigated. Overall consideration of the transmittance and thermal properties of the samples, the optimal concentration of Y3+ ion was about 1 at.%.

Novel Ba(Gd1-xYx)0.78F5: 20 mol% Yb3+, 2 mol% Tm3+ (0 ≤x ≤1.0) solid solution nanocrystals: A facile hydrothermal controlled synthesis, enhanced upconversion luminescent and paramagnetic properties

Ba(Gd1-xYx)0.78F5: 20 mol% Yb3+, 2 mol% Tm3+ (0 ≤ x ≤ 1.0) solid solution nanocrystals were successfully synthesized via a facile hydrothermal method, the obtained crystals were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), the transmission electron microcopy (TEM), energy dispersion spectrometry (EDS), photoluminescence (PL) as well as vibrating sample magnetometer (VSM), respectively. The influences of the concentration of yttrium ion (Y3+) on the microstructures, upconversion (UC) luminescent and magnetic properties of the Ba(Gd1-xYx)0.78F5: 20 mol% Yb3+, 2 mol% Tm3+ samples have been deeply investigated. XRD results showed that all the Ba(Gd1-xYx)0.78F5: 20 mol% Yb3+, 2 mol% Tm3+ crystals are continuous solid solution possess a pure cubic phase structure. SEM and TEM results revealed that all the obtained crystals are quasi-spherical nanocrystals with a diameter ranging from ∼55 nm to ∼240 nm, and the doping of Y3+ ion can inhibit the grain growth. PL spectra indicated that all the samples exhibit main blue emission centered at 478 nm ascribed to 1G4→3H6 transition of Tm3+ ions, and its UC emission intensity initially increases and then notably decreases with increasing content of Y3+ ion, giving the maximum at x = 0.8. VSM results showed that all the samples present benign paramagnetism in the magnetic range of −30 to 30 kOe at 300 K due to no coercivity or no remanence. Our results confirm that the UC luminescence properties of the Ba(Gd1-xYx)0.78F5: 20 mol% Yb3+, 2 mol% Tm3+ nanocrystals can be effectively modulated through the replacement of Gd3+ ions by Y3+ ions, which also can provide a relatively clear understanding of the formation process and the enhancement mechanism of UC emission for other rare earth polyfluoride solid solution nanocrystals.

Dielectric, piezoelectric and conduction properties of yttrium acceptor-doped BaTiO3 ceramics

BaTi1−xYxO3−x/2 ceramics were prepared by using a solid state reaction process. All the samples have a tetragonal structure below the solution limit of 3 at.%. And the doping of Y3+ inhibits the grain growth of BaTiO3 ceramics. In addition, substitution of Y3+ at B-site in BaTiO3 leads to an increase of Curie temperature (Tc). Specifically, the sample with x = 0.015 has the raised Tc temperature (136 °C) and exhibits a larger electric field induced strain (0.27 %) at the electric field of 65 kV/cm and room temperature. Besides, oxygen loss is restrained due to the incorporation of Y3+ in BaTiO3. Conductivity of the sample with x = 0.005 is dominated by a p-type conduction in air and oxygen, while in nitrogen, oxygen loss leads to it changes to an n-type conduction. However, the sample with x = 0.02 behaves a mixed conduction in oxygen, air and nitrogen, in which the species responsible are primarily O2− ions and holes.

Preparation and photocatalytic activity of Y-doped Bi2O3

Y3+ doped Bi2O3 photocatalysts with enhanced photocatalytic activity were synthesized via thermal decomposition of molecular precursor at 500 °C and characterized by X-ray powder diffraction (XRD), Brunauer–Emmett–Teller surface area, field emission scanning electron microscopy (FE-SEM), energy dispersive analysis of X-rays (EDX), ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), and photoluminescence spectra (PL). The XRD results indicated that the introduction of Y3+ ions can stabilize the phase of Bi2O3. The DRS results indicated that the doping of Y3+ increased the visible light absorption ability of Bi2O3 and red-shifts appeared when compared with pure Bi2O3. Their photocatalytic activities were evaluated through the photocatalytic degradation of methyl orange. The results showed that an appropriate concentration of yttrium dopant can enhance the photocatalytic performance of Bi2O3 due to the strong visible light absorption and the efficient inhibition of the recombination of photogenerated electron–hole pairs. The active species trapping experiments indicated ·O2− is the main active species in the photocatalytic reaction. Recycling experiments demonstrated that Y-doped Bi2O3 has strong photostability and recyclability and it will be a promising photocatalyst for the photodegradation of organic dyes in water.

Photocatalysis and Hydrophilicity of Y<sup>3</sup><sup>+</sup> Doped TiO<sub>2</sub> Thin Films

Y3+ doped TiO2 coatings were successfully prepared on glass slide substrates. The phase structure, optical properties，microstructure and surface properties of the coatings were characterized by using XRD, FT-IR, UV-vis and SEM. The photoinduced super-hydrophilicity and photocatalytic activity of the films were evaluated by the water contact angle measurement and photocatalytic oxidation of Rhodamine B in air, respectively. The results indicated that the doping of Y3+ into TiO2 could improve the hydrophilicity and photocatalytic activity, and TiO2 thin films doped with Y3+ at 2-4 at.% and heat-treated at 450 oC were of super-hydrophilicity. The optimal Y3+ content for the photocatalytic activity was 4 at.% and larger film thickness was helpful to reduce the contact angle of the composite films.

Luminescent properties of a new blue long-lasting phosphor Ca2P2O7:Eu2+, Y3+

A new pyrophosphate long-lasting phosphor with composition of Ca1.96P2O7:0.02Eu2+, 0.02Y3+ is synthesized via the high-temperature solid-state reaction method. Its properties are systematically investigated utilizing XRD, photoluminescence, phosphorescence and thermoluminescence (TL) spectra. The phosphor emits blue light that is related to the characteristic emission of Eu2+ due to 5d–4f transitions. For the optimized sample, bright blue long-lasting phosphorescence (LLP) could be observed by naked eyes even 6h after the excitation source is removed. The TL spectra show that the doping of Y3+ ions greatly enhanced intensity of 335K peak and created new TL peak at about 373K that is also responsible for the blue LLP. Based on our study, Y3+ ions are suggested to act as electron traps to improve the performance of the blue phosphorescence of Eu2+ such as intensity and persistent time.

Synthesis and electrochemical properties of yttrium-doped LiMn0.98Y0.02O2 for lithium secondary batteries

Yttrium-doped lithium manganese oxide (LiMn0.98Y0.02O2) was prepared by ion exchange of lithium for sodium in NaMn0.98Y0.02O2 precursors obtained by using rheological phase reaction method. This material had small particle size, which was composed of grain size of about 100 nm. Especially, LiMn0.98Y0.02O2 delivered the initial discharge capacity of about 191 mA h g−1 at room temperature when cycled between 2.0 and 4.4 V vs Li/Li+. Moreover, it showed an excellent cycling behavior, its specific capacity remained above 173 mA h g−1 after 20 cycles, and the material did not transform into spinel structure during the electrochemical cycling according to the cyclic voltammograms and X-ray powder diffraction. The electrochemical results revealed that the doping of Y3+ improved the performance of LiMnO2 considerably.

Pd-, Pt-, and Rh-Loaded Ce0.6Zr0.35Y0.05O2 Three-Way Catalysts: An Investigation on Performance and Redox Properties

The redox behaviors, oxygen mobilities, and oxygen storage capacities of Ce0.6Zr0.4O2 (CZ), Ce0.6Zr0.35Y0.05O2 (CZY), and 0.5 wt% M/CZY (M=Pd, Pt, Rh) as well as the three-way catalytic performance of the noble metal-loaded CZY materials have been investigated. It is observed that at a space velocity of 60,000 h−1 and in an atmosphere close to the theoretical air-to-fuel ratio (i.e., 14.6), the CZY-supported precious metal catalysts showed good three-way catalytic activity. X-ray diffraction investigations revealed that there are two phases (cubic Ce0.75Zr0.25O2, major; cubic ZrO1.87, minor) in CZ, CZY, and 0.5 wt% M/CZY. These materials are porous and large in surface area. According to the results of Ce 3d X-ray photoelectron spectroscopic studies, the doping of Y3+ ions into the CZ lattice would cause the concentrations of oxygen vacancies and Ce3+ ions to increase. The results of H2(or CO)–O2 titration and temperature-programmed reduction–reoxidation experiments indicate the presence of a reversible redox behavior of Ce4+/Ce3+ couples. The results of 18O/16O isotope exchange studies show that in the presence of oxygen vacancies and noble metals, the mobility of lattice oxygen on/in CZY is promoted. Based on the above outcomes, we suggest that by incorporating Y3+ ions into CZ and loading Pd, Pt, or Rh on CZY, one can enhance (i) lattice oxygen mobility, (ii) Ce3+ ion concentration, and (iii) oxygen uptake capacity of the CZY solid solution, generating a class of materials suitable for the catalytic conversion of automotive exhaust.

Surface temperature of a hot film on a wall in shear flow

The temperature sensitive paint (TSP) technology is widely used in the temperature distribution measurement of large area solid field, especially for the in-depth research in the mechanical behavior of complex flow gas around the aircraft, because of its advantages of non-contact, full-field measurement, easy manufacture and use. In this work, we synthesized the rare earth ion(Y3+, Er3+) doped Eu(TTA)3phen/PMMA temperature sensitive paint respectively based on the probe molecules of the rare earth ion (Y3+, Er3+) doped Eu(TTA)3phen and polymethyl methacrylate(PMMA). The structure of probe molecules and the fluorescent properties of TSP were also studied. The result show that the optimal ratio of Eu3+:Y3+ (or Er3+) is 0.5:0.5, rare earth ions are coordinated with ligands and the doping of Y3+ and Er3+ do not affect the structure of Eu(TTA)3phen. Y3+ and Er3+ have gain effect on the fluorescent emission of Eu(TTA)3phen/PMMA and the strongest fluorescent intensity (616 nm) is decreased with the increasing of temperature, which show that the Y3+ and Er3+ doped Eu (TTA)3phen/PMMA have temperature quenching properties in the temperature range of 20–80 °C. What’s more, the doping of Y3+ and Er3+ can improve the change rate of the fluorescent intensity and the temperature measurement sensitivity.