Yttrium Hydroxide Research Articles

Synthesis of Yttrium Oxide Nanoneedles with Carbon Dioxide Carbonization.

In this study, a CO2 carbonization method is introduced for the preparation of 1D yttrium oxide powders. Using YCl3 as the raw material, sodium hydroxide was initially used to completely precipitate Y3+ into yttrium hydroxide, and then CO2 was introduced into the yttrium hydroxide slurry for homogenization-like carbonization to obtain yttrium carbonate precipitation. Then, by studying the effects of carbonization conditions, such as the temperature, CO2 flow rate, and stirring speed, on the morphology and phases of yttrium carbonate, the temperature was observed to exert a greater effect than the other experimental parameters on the morphology and structure of the carbonized products. Finally, Y2(CO3)3·2H2O nanoneedles were obtained at optimal conditions. The carbonized crystals of the acicular yttrium carbonate precipitate because of the solution supersaturation and then quickly complete their crystal growth process through the oriented attachment (OA) and Ostwald ripening (OR) mechanisms. After heat treatment, yttrium carbonate retained a good crystal morphology and produced Y2O3 nanoneedles with a length of 1–2 μm and a width of 20–30 nm.

Room temperature crystallization of YVO4:Yb3+,Ho3+ nanoparticles using LYH and fabrication of transparent up-converter films

Layered yttrium hydroxide (LYH) was explored for the synthesis of a representative up-converting YVO4:20%Yb3+,0.4%Ho3+ particles in aqueous Na3VO4 solutions at room temperature. No formation of the VO43−-intercalated LYH:Yb3+,Ho3+ phase during reaction suggested the sequential transformation from the outermost sheet of LYH:Yb3+,Ho3+ to YVO4:Yb3+,Ho3+ particles with regular shape and size without a general tendency to aggregate. Because of remnant hydroxyl groups in the particles transformed structurally from the hydroxide precursor, the up-conversion emission was too weak to be measured for the as-prepared YVO4:Yb3+,Ho3+ and after heating at lower than 200 °C. In contrast, the luminescence intensity of YVO4:Yb3+,Ho3+ was dramatically enhanced with increasing the annealing temperature up to 700 °C. The prepared elliptical shape particles maintained high dispersibility even after annealing at 700 °C so that they were exploited for the fabrication of transparent and flexible composite up-converter films with high efficiency via simple casting of PVA suspensions containing YVO4:Yb3+,Ho3+ particles.

Ceramic molds based on yttrium oxide for the casting of titanium alloys

The effect of various binding agents based on aqueous solutions of nitric acid, yttrium nitrate and orthophosphoric acid and yttrium hydroxide gel on the physical and mechanical properties of casting molds based on Y2O3 has been studied. It is shown that the most promising binding agent for yttrium oxide casting molds is a phosphate bond. The data describing the curing mechanism of phosphate-bonded molding mass is presented. The influence of the concentration of binding agent solutions on the strength characteristics of molding materials after curing and heat treatment is shown. Information about the interaction of yttrium oxide powder molds with phosphate-binding with titanium melt of VT1-0 and VT6 grades is presented. The obtained data allowed us to describe the advantages and disadvantages of the developed molding compound. A method for producing casting molds based on yttrium oxide powder with a yttrium phosphate-binding agent was developed based on this research.

Luminescent oxygen-sensing film based on Eu (III)-doped yttrium hydroxide nanosheets

Quantification of molecular oxygen in liquid phases is an important analytical problem in the fields of chemistry, food industry, biomedicine, environmental monitoring, and safety at work. In this paper, we prepared a β-diketone-modified Eu (III)-doped yttrium hydroxide nanosheet (Y(Eu)NNS) to obtain a novel oxygen sensor which can detect the dissolved oxygen based on luminescence intensity quenching. The narrow luminescence bands of the Eu (III)-doped yttrium hydroxide nanosheet are particularly suitable for oxygen detection because of the large stokes shift and excellent luminescence performance. The prepared rare earth nanosheets feature all advantages of rare earth complexes, not only displaying unique chemical and physical properties due to the unusual structural features such as excellent two-dimensional anisotropy, but also enhanced luminescence and higher stability compared to rare earth complexes. The Y(Eu)NNS formed film with high photostability exhibited high sensitivity and a well-linear response, making it a promising material for dissolved oxygen sensing and optical fiber sensing.

Synthesis of spherical Y2O3:Er emitting particles with variable radial composition by controlled double-jet precipitation of layered precursors

Spherical (Y0.98Er0.02)2(OH)5(NO3)·xH2O particles were synthesized by controlled double-jet precipitation, with a “core” of pure layered yttrium hydroxide nitrate, and a “shell” of co-precipitated yttrium-erbium layered hydroxide nitrates. With an increase in precipitation pH from 7 to 9.5, the size of layered “building units” decreases and the architecture of their assemblies changes from flower-like through network-like spherical to irregular agglomerates. From there, spherical particles gradually increase their diameter due to the continuous uniform growth of curved layered sheets on their surface. It was established that such growth behavior and network-like architecture of spherical particles was retained even when yttrium was replaced by erbium ions in the layered host lattice during the formation of an Er-enriched “shell”. Analysis of SEM, EDS, XPS, photoluminescence spectra and concentration quenching effects of heat-treated Y2O3:Er (2 at.%) particles indicate that the radial distribution of erbium in particles is most controllable in a narrow pH range of co-precipitation of layered precursors (pH 8). Вy widely varying the elemental composition of “building units” during co-precipitation, one can simultaneously finely control the composition of layered hydroxides in the radial direction of the spherical particles and grow multicomponent “multi-shell” powders with desired properties.

High crystalline quality of hydrophilic LiYF4: Tm3+/Yb3+ particles prepared by fluorination of layered yttrium hydroxides under assistance of DTPA

Up-conversion emissions can be achieved by doping Tm3+ in hydrophilic LiYF4 crystal particles, with Yb3+ as a sensitizer. They are considered to be excellent up-conversion materials used in bioimaging. However, the crystalline quality of hydrophilic LiYF4 particles prepared by traditional methods is not satisfied and lowers the fluorescent performance. Herein, some additives were employed in preparation of LiYF4 crystals via fluorination transformation from layered yttrium hydroxides (LYHs). The reaction mechanism of additives was discussed in detail. Especially, diethylenetriaminepentaacetic acid (DTPA) can effectively promote the crystallization and Oswald ripening of LiYF4 crystals. The as-prepared LiYF4: Tm3+/Yb3+ up-conversion phosphors have a marvelously intense emission at 793 nm and would be beneficial to the application in bioimaging.

Investigating transformation kinetics of yttrium hydroxide to yttrium oxide

The transformation kinetics involved during the formation of yttrium oxide through thermal dehydration of yttrium hydroxide was studied through differential thermal analysis (DTA) at multiple heating rates (1, 5, 7, 10 °C/min) in air. The yttrium hydroxide dehydrates in two steps to form yttrium oxide. The intermediate compound, i.e., YOOH was formed at 350 °C. The phase formation was confirmed through XRD and Le-Bail profile matching. FESEM confirms the dehydration of yttrium hydroxide and a rod-shaped microstructure was observed. An increase in temperature resulted in shrinkage of the rods. The kinetic triplets (activation energy, pre-exponential factor and reaction mechanism) were estimated for both the steps. The Straink method was used to evaluate activation energy, whereas the reaction mechanism was identified through the integral master plot method. The activation energy was 219.6 kJ/mol and 431.3 kJ/mol for step I and II of dehydration, respectively. Step I was dominated by the A2 reaction mechanism, while the F1 reaction mechanism was found in step II of yttrium hydroxide dehydration.

Facile Preparation of YVO4: RE Films and the Investigation of Photoluminescence

Facile preparation of YVO4 films was hydrothermally achieved within 1 h by using layered yttrium hydroxide (Y2(OH)5NO3·nH2O) films as the sacrificial precursor in the presence of excess NaVO3 at pH~8, without subsequent heat treatment. Detailed structures and optical properties of the products were obtained by using a combination of XRD, FT-IR, FE-SEM, HR-TEM, and PLE/PL techniques. The phase and morphological evolution from Y2(OH)5NO3·nH2O to YVO4 was unveiled by varying the reaction time. Photoluminescence spectra showed that the Eu3+ doped YVO4 films exhibited the characteristic emission of Eu3+, with the transition 5D0–7F2 (614 nm, red) being the dominant; while Dy3+ activator doped YVO4 films exhibited the characteristic emission of Dy3+, with the transition 4F9/2–6H13/2 (575 nm, green) being the most dominant.

Exploring the intercalation chemistry of layered yttrium hydroxides by 13C solid-state NMR spectroscopy

Layered rare earth hydroxides (LREHs) are a novel class of two-dimensional materials with potential applications in various fields. The exchange reactions with organic anions are typically the first step for the functionalization of LREHs. Although the laminar structures seem to be clear for anion-exchanged compounds, the state of intercalated organic anions and their interactions with cationic rare earth hydroxide layers remain unclear. Herein, we demonstrate that the use of 13C solid-state nuclear magnetic resonance (ssNMR) spectroscopy enables to extract key information on the state of intercalated organic anions such as their local chemical environment, stacking, and dynamics, which are often difficult or impossible to obtain previously. In combination with powder X-ray diffraction and ab initio density functional theory calculations, the intercalation chemistry of two representative layered yttrium hydroxides with selected monovalent organic anions was studied in detail. The products can undergo secondary exchange with a divalent organic anion, depending on the match between the basal spacing of two phases, i.e., the replacement of benzenesulfonate (BS−), 2,4-dimethylbenzene sulfonate (DMBS−), and 4-ethylbenzene sulfonate (EBS−) with 2,6-naphthalene disulfonate (NDS2−) is allowed due to the insignificant change in basal spacing after exchange, while the replacement of very long dodecyl benzene sulfonate (DBS−) and dodecyl sulfate (DS−) with NDS2− is forbidden. The results therefore provide valuable insights into the structure-property relationships of LREH-based functional materials.

Supercapacitive performance evaluation of chemically synthesised binder free Y(OH)3 electrode

Rare earth group elements have gained the renewed interest in applications of energy storage and conversion. Apparently, supercapacitive performances of electrodes based on yttrium (Y+3) element are still left uncovered for exploration as energy storage device. In this study, the binder free yttrium hydroxide (Y(OH)3) electrodes have been prepared through easy, economical and industry applicable successive ion layer adsorption and reaction (SILAR) method. The Y(OH)3 has been deposited over the stainless steel (SS) substrate for 10 (Y_10), 20 (Y_20) and 30 (Y_30) SILAR cycles. The prepared electrodes have been characterized by using X‐ray diffraction (XRD), fourier‐transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM). The electrochemical performances of the prepared electrodes have been studied in presence of 1 M Na2SO4 electrolyte. The Y_20 shows the superior electrochemical performance than others. The highest specific capacity of 237 C g−1 has been observed for Y_20 at 1 mA current rate along with good cycle stability. Thus, by observing our results, one can say that the prepared electrode has a great potential in area of energy harvesting, power back up, portable devices, etc.

Specific lift-up behaviour of acetate-intercalated layered yttrium hydroxide interlayer in water: application for heterogeneous Brønsted base catalysts toward Knoevenagel reactions

The basal (00l) plane of acetate-intercalated layered yttrium hydroxide (CH3COO−/Y-LRH), synthesised by an anion exchange using Cl−/Y-LRH as a parent material, increased in water, and the lifted-up layered structure was generated immediately.

Yttrium Oxide-Catalyzed Formation of Electrically Conductive Carbon for Supercapacitors

The development of electrically conductive and high surface area carbon is important for the improvement of supercapacitor energy densities. Yttrium hydroxide microspindles were prepared and shown ...

La3+ and Y3+ interactions with the carboxylic acid moiety at the liquid/vapor interface: Identification of binding complexes, charge reversal, and detection limits

Specific interactions of yttrium and lanthanum ions with a fatty acid Langmuir monolayer were investigated using vibrational sum frequency spectroscopy. The trivalent ions were shown to interact with the charged form of the carboxylic acid group from nanomolar concentrations (<300 nM). Analysis of the spectral features from both the symmetric and the asymmetric carboxylate modes reveals the presence of at least three distinct coordination structures linked to specific binding configurations. Although the same species were identified for both La3+ and Y3+, they display a different concentration dependence, highlighting the ion-specificity of the interaction. From the analysis of the response of interfacial water molecules, the reversal of the surface charge, as well as the formation of yttrium hydroxide complexes, were detected upon increasing the amount of salt in solution. The binding interaction and kinetics of absorption are sensitive to the solution pH, showing a distinct ion speciation in the interfacial region when compared to the bulk. Changing the subphase pH or adding a monovalent background electrolyte that promotes deprotonation of the carboxylic acid headgroup could further improve the detection limit of La3+ and Y3+ to concentrations < 100 nM. These findings demonstrate that nM concentrations of trace metals contaminants, typically found on monovalent salts, can significantly influence the binding structure and kinetics in Langmuir monolayers.

Layered Yttrium Hydroxide as a Host for Enhancing the UV‐Protective Capacity and Photostability of Benzophenone‐5

AbstractLayered yttrium hydroxide (LYH) was explored as a host material for a highly efficient organic UV‐absorber, 2‐hydroxy‐4‐methoxybenzophenone‐5‐sulfonic acid (BP5), with the intercalation of BP5 anions into the interlayer galleries of LYH. On the basis of the powder X‐ray diffraction (XRD) pattern and Infrared (IR) spectra of the resulting BP5‐LYH hybrid, it was suggested that the double aromatic rings of BP5 anion are arranged parallel to the hydroxocation layers in the interlayer space in LYH. Thermogravimetry (TG) curves indicated the incomplete inclusion of BP5 anions due to the insufficiency of the lateral area of the interlayer space in LYH to accommodate the parallel arrangement of fully exchanged BP5 anions. The UV absorption band of BP5 was so broad as to absorb over the full UV range after intercalation in the LYH host. Long‐term use tests showed that BP5 was not significantly released from the LYH matrix in artificial seawater. This hybrid was well dispersed in a PVA solution to produce transparent BP5‐LYH/PVA composite UV‐filter films. The BP5‐LYH hybrid exhibited excellent photostability in PVA composites, maintaining complete UV‐filtering performance under simulated sunlight. A BP5‐LYH hybrid could therefore be a promising candidate not only as a UV‐filter that does not release BP5 into aquatic systems but also as a transparent outdoor UV‐screening polymer film whose single species covers the full UV range.

Kinetics of Thermal Decomposition of Yttrium and Samarium Hydroxides and Sm(OH)3@Y(OH)3 Compound with a Core–Shell Nanostructure

Kinetics of Thermal Decomposition of Yttrium and Samarium Hydroxides and Sm(OH)3@Y(OH)3 Compound with a Core–Shell Nanostructure

Controlling the morphology of nanocrystalline Y(OH)3 powders synthesized by microwave-hydrothermal route and effect of annealing

Y(OH)3 is the main precursor material to inherit desirable morphologies for Y2O3. The Y(OH)3 and Y2O3 are an important substitution for luminescent matrix and useful in temperature sensing applications. Nanostructured and phase-pure Y2O3 is also used as an essential dispersoid for the oxide dispersion strengthened steels which are candidate materials for future fast breeder reactors. In the present work, the nanostructured Y(OH)3 is prepared indigenously by the microwave-hydrothermal route which is appropriate to provide-uniform heating to the material and the hydrothermal-pressure environment plays a major role in the growth kinetics of morphology. The synthesis was carried out at various microwave powers of 700 and 800 W to obtain the different morphologies of tubular and rod-like structures, respectively. The morphology is attributed to the influence of heat-rate on the variation in hydrothermal pressure governed by microwave power. The morphologies remain the same on calcination 800 °C. As-synthesized powder samples showed hexagonal structure whereas the cubic structure was observed for those calcined at 800 °C for both morphologies. The hydroxide vacancies lead to form a cubic structure that has a larger unit cell. The yttrium oxides showed lattice compaction for the rod-like structure but yttrium hydroxides did not depict any difference in the lattice for the tubular and rod-like morphologies. Likewise, Raman spectroscopy analysis confirmed the formation of hexagonal and cubic phases for the as-synthesized and calcined nanopowder samples, respectively.

“X Factor” in the Structure and Anion Exchange of Layered Yttrium Hydroxides

The anion-exchangeable family of layered rare-earth hydroxides RE2(OH)5X·nH2O (LREH-X, RE = rare-earth elements such as Y, X– = monovalent anions, n ≈ 1.5) exhibits considerable potential in variou...

A novel approach of synthesizing nano Y2O3 powders for the fabrication of submicron IR transparent ceramics

A facile methodology of synthesizing highly reactive, round-edged, Sulfur–free nano Y2O3 powders to fabricate submicron IR transparent yttria ceramics having a unique combination of superior optical and mechanical properties are reported for the first time. Dispersion of yttrium hydroxide into aqueous sol and addition of seed particles produced near-spherical yttria powders having non – aggregated particles with narrow size distribution. The powder exhibited excellent sinterability reaching near-theoretical density at temperatures around 1400 °C in air. Effective inter-particle coordination and traces of Al additives assisted achieving superior densification. Sintered specimens showed average grain sizes closer to 700 nm. Post-sinter hot isostatic pressing eliminated the residual porosity from the sintered samples leading to exhibit IR transmissions up to 84% in the 2.0–9.0 μm regions, equivalent to single crystal Y2O3. Achieving densification through solid-state sintering and retaining the sintered grain sizes in the submicron regions significantly enhanced the mechanical properties. Sintered and HIPed Y2O3 specimens were further characterized for their thermal properties at temperature regions between ambient to 950 °C.

89Y chemical shift anisotropy: a sensitive structural probe of layered yttrium hydroxides revealed by solid-state NMR spectroscopy and DFT calculations

A combination of solid-state NMR (ssNMR) spectroscopy and DFT calculations revealed that the89Y CSA is a sensitive probe to detect the subtle structural changes in layered yttrium hydroxides.

Layered yttrium hydroxide composite as supersensitive fluorescent sensor on Fe(III) ions

The synthesized HN/OS-LYH composite (HN: 3-hydroxy-2-naphthoic acid, OS: 1-octane sulfonate, LYH: layered yttrium hydroxide) demonstrates tuned luminescence performance and sensitive recognition capability for Fe3+. In solid state, the HN/OS-LYH presents a green emission of 505 nm, with 40 nm blue shift relative to the 545 nm green emission of free HN-Na salt; under delamination in formamide (FM), the HN/OS-LYH displays a blue emission of 480 nm in contrast to a 515 nm emission of HNˉ in FM solution. The delaminated HN/OS-LYH exhibits excellent recognition capability towards Fe3+ with distinct fluorescence quenching. For Fe3+, a much large quenching constant of 3.85 × 103 M−1 and an extremely low detection limit of 1.14 × 10-8 M are achieved. The HN/OS-LYH is expected to be a "turn-off" type fluorescent sensor for Fe3+ detection. This work may provide new ideas for design of novel LRH composites which can be applied on fluorescent sensoring.