Yttrium Hydroxide Research Articles

The Ordering and Arrangement of Intercalated Carboxylate Ions in Anion‐Exchangeable Layered Yttrium Hydroxides

AbstractThe intercalation chemistry is essential in the application of anion‐exchangeable layered metal hydroxides. However, much of the key information regarding intercalated anions, such as the degree of ordering and arrangement is still not clear or missing to date, due to the difficulty in probing the local environment of anions by routine characterization techniques. Herein, we employed solid‐state NMR (ssNMR) spectroscopy to offer valuable complementary insights into the ordering and arrangement of a series of monocarboxylate anions (RCOO−: R=HO, H, CH3, C2H5, and C3H7) within the interlayer space of two layered yttrium hydroxides (LYH‐Cl and LYH‐Br). The results imply that the two smaller carboxylate anions (R=HO and H) are disordered after intercalation, while the larger carboxylate anions (R=CH3, C2H5, and C3H7) are relatively ordered. We further explored if the intercalated anions are parallel arranged as those in sodium salts or antiparallel arranged as those predicted in the majority of previous reports. We uncovered that the intercalated anions are antiparallel arranged based on the formation energy obtained in density functional theory calculations and ssNMR data. Our results therefore contribute to a deeper and comprehensive understanding of the intercalation chemistry of layered rare earth hydroxides.

Facile synthesis of nanoflowers of immobilized enzyme using layered rare earth hydroxides as carriers and their application for detection of H2O2 and phenol

This study reports a simple method for synthesizing the nanoflower-immobilized enzyme (LYH-HRP) using horseradish peroxidase (HRP) as the bioenzyme and layered yttrium hydroxide (LYH) as the inorganic carrier. Utilizing the structural advantage of LYH and the catalytic properties of HRP, a nanoflower-based colorimetric platform was newly designed and applied for sensitively detecting H2O2 and phenol with a detection time of as fast as 5 min. The limits of detection (LODs) for H2O2 and phenol are as low as 0.046 μM and 0.778 μM, respectively. The activity and stability tests showed that the activity of LYH-HRP was 1.52 times that of free HRP, and it maintained 75% of the initial activity after 60 days.

Rapid, Micron-Resolution 3D Printing of Nd:YAG Ceramic with Optical Gain.

Polycrystalline yttrium aluminum garnet (YAG) ceramic doped with neodymium (Nd), referred to as Nd:YAG, is widely used in solid-state lasers. However, conventional powder metallurgy methods suffer from expenses, time consumption, and limitations in customizing structures. This study introduces a novel approach for creating Nd:YAG ceramics with 3D free-form structures from micron (∼70µm) to centimeter scales. Firstly, sol-gel synthesis is employed to form photocurable colloidal solutions. Subsequently, by utilizing a home-built micro-continuous liquid interface printing process, precursors are printed into 3D poly(acrylic acid) hydrogels containing yttrium, aluminum, and neodymium hydroxides, with a resolution of 5.8µm pixel-1 at a speed of 10µm s-1. After the hydrogels undergo thermal dehydration, debinding, and sintering, polycrystalline Nd:YAG ceramics featuring distinguishable grains are successfully produced. By optimizing the concentrations of the sintering aids (tetraethyl orthosilicate) and neodymium trichloride (NdCl3), the resultant samples exhibit satisfactory photoluminescence, emitting light concentrated at 1064nm when stimulated by a 532nm laser. Additionally, Nd:YAG ceramics with various 3D geometries (e.g., cone, spiral, and angled pillar) are printed and characterized, which demonstrates the potential for applications, such as laser and amplifier fibers, couplers, and splitters in optical circuits, as well as gain metamaterials or metasurfaces.

Stability, release, and tyrosinase inhibition behaviors of kojic acid encapsulated in the interlayer space of layered yttrium hydroxide

Kojic acid (KA) is widely utilized in cosmetic formulations for skin brightening and as a food preservative to prevent oxidative browning in fruits and vegetables. However, its effectiveness is compromised by susceptibility to pH and temperature fluctuations, as well as oxidation after exposure to UV light. These limitations highlight the need for improvements to facilitate sustainable applications. In this study, KA was encapsulated within the interlayer space of layered yttrium hydroxide (LYH) through a two-step host-guest reaction involving dodecylsulfate and basic ethoxide anions. Examination of the X-ray diffraction (XRD) pattern of the resulting product (KA-LYH) revealed an expanded interlayer space from approximately 8.4 to 16.7 Å, conducive to a partially interdigitated bilayer arrangement of KA anions within the LYH interlayer. KA-LYH demonstrated significantly improved stability against light, heat, and oxygen compared to free KA, indicating effective confinement and protection of KA from photoreaction and oxidation in the interlayer space of LYH host. Minimal release of KA was observed in saline solution and simulated seawater, while sustained release occurred in a phosphate buffer solution even after 24 h. Notably, the KA released from the LYH interlayer space retained potent tyrosinase inhibition activity, showcasing the sustainable efficacy of KA-LYH under physiological conditions.

Monolayer calcium-doped layered yttrium hydroxide adsorbent for rapid and efficient removal of fluoride from industrial wastewater

Strategies for the rapid and efficient removal of fluoridated industrial wastewater are currently lacking. Herein, monolayer calcium-doped layered yttrium hydroxide (Ca-Y LRH) was synthesized through formamide exfoliation, and its removal of fluoride reached equilibrium within 4 min. The adsorption kinetics fit the pseudo-second-order kinetic model with a faster adsorption rate (KF = 0.22 mg g−1 min−1), and the adsorption isotherm followed the Langmuir model with a maximum adsorption capacity of 483.33 mg g−1. The interlayer chloride ions in the monolayer Ca-Y LRH were the main ligands for substituting fluoride, which inhibited the increase in pH and maintained the continuation of the fluoride removal process. Furthermore, the optimum fluoride removal performance of monolayer Ca-Y LRH was predicted by software-based multiparameter methods and was found to be useful for treating fluoridated industrial wastewater samples (858.17 or 8.72 mg L−1). These findings provide novel insights into the treatment of fluoridated industrial wastewater.

Fabrication of hierarchical 3D layered yttrium hydroxide nanocomposites: Their use for enzyme immobilization and catalysis of H2O2

3D layer metal hydroxides (LMHs) have attracted significant interest due to their distinctive structural features. Unfortunately, the limited electrical conductivity hinders the potential utilization of LMHs in electrochemical analysis. To address this issue, herein, gold nanoparticles (AuNPs) were introduced to layered yttrium hydroxides by a facile in-situ electrodeposition method. Subsequently, the hierarchical AuNPs/LYH nanocomposite was employed as solid supports for immobilization of horseradish peroxidase, generating an enzymatic biosensor for hydrogen peroxide detection. As a result, a linear range of 1–500 μM with a remarkably low detection limit of 0.33 μM (S/N=3) was achieved. Moreover, the biosensor also demonstrated excellent selectivity, reproducibility and stability. The superior electrochemical responses of the HRP/AuNPs/LYH nanocomposite towards H2O2 can be ascribed to the synergistic effect arising from the flower-like structures of LYHs and the high conductivity of AuNPs. Our study provides a significant approach for the development of enzyme immobilized supports through the construction of layer metal hydroxide nanocomposites.

A comprehensive solid-state NMR and theoretical modeling study to reveal the structural evolution of layered yttrium hydroxide upon calcination

Layered rare earth hydroxides (LREHs) are a new family of ion-exchangeable layered metal hydroxides, which have extensive applications in various fields due to the unique properties of rare earth cations in the layered structure and the anion exchange capacity. The transformation of layered metal hydroxides to new layered phases that can be restored through the memory effect is critical for their chemistry and applications. However, the structure details of these new phases such as the coordination environments of rare earth cations/counterions and their evolution as a function of calcination temperature remain unclear to date. Herein, a comprehensive 89Y/35Cl solid-state NMR (ssNMR) and theoretical modeling approach was used to reveal the structural evolution of a representative LREH, namely LYH-Cl, upon calcination. We first identified partial decomposition products of Y3O(OH)5Cl2 and Y(OH)3 during the dehydration stage, then uncovered the preferential removal of hydroxide ions on yttrium sites coordinated with chlorine during the dehydroxylation stage, and finally determined the preferential removal of chlorine exposed to the surface of layers during the dechlorination stage. The coordination environments of Y3+ and Cl− undergo significant changes upon calcination, revealed by ssNMR experiments. These findings thus help us to overcome the obstacles impeding the rational design and synthesis of LREH-based functional materials via memory effect, underscoring the vast potential of ssNMR in deepening the understanding of layered metal hydroxides and related materials.

Solution Processing Silicon Heterojunction Photocathode for Efficient and Stable Hydrogen Production.

Efficient and stable photocathodes are crucial for the development of photoelectrochemical (PEC) water-splitting devices. Silicon heterojunction (SHJ) solar cell is one of the most advanced photovoltaic cells. However, due to the instability of its outermost indium tin oxide (ITO) layers in the electrolyte, a protective layer needs to be introduced on its surface. Previously reported high-quality protective layers almost all involved the use of expensive thin film manufacturing techniques such as atomic layer deposition (ALD). In this work, for the first time, a new strategy is proposed of modifying SHJ-based photocathode with yttrium hydroxide (Y(OH)3) through two-step solution methods to simultaneously improve the stability and activity. The optimized SHJ photocathode exhibits a high applied bias photon-to-current efficiency (ABPE) of 8.4% under simulated 100mWcm-2 (1 Sun) with an AM 1.5G filter in 0.5m KOH. Furthermore, the obtained SHJ photocathode demonstrates excellent stability of at least 110h at 0.3V versus RHE. In this work, combining facile direct current magnetron sputtering with a solution treatment technique provides a novel design strategy, which lowers the threshold for preparing high-quality protective layer, and paves the way for developing economic, efficient, and stable SHJ-based PEC devices.

Fluorination of Eu-doped layered yttrium hydroxides: the role of anionic composition

Fluorination of Eu-doped layered yttrium hydroxides: the role of anionic composition

Building composite of layered yttrium hydroxide and carbon nanotube as the sulfur host for high-performance lithium‑sulfur batteries

The commercialization of lithium‑sulfur batteries is still confronting with great challenges due to the sluggish redox kinetics of sulfur and the shuttle effect of lithium polysulfides (LiPS). Herein, two-dimensional (2D) layered yttrium hydroxide (LYH) nanosheets are in-situ grown on multiwalled carbon nanotubes (CNTs) and used as a multifunctional host material (LYH@CNT) for sulfur loading. The crosslinked CNTs provide a robust and conductive network for quick charge transfer and sufficient active site exposure, while LYH nanosheets demonstrate strong ability for anchor and catalytic conversion of lithium polysulfides. The theoretical calculation and adsorption experiment also confirm the strong adsorption of LYH for lithium polysulfides. Therefore, sulfur loaded on LYH@CNT exhibits excellent electrochemical performance, such as a good cycling stability with a capacity of 484 mAh g−1 after 800 cycles at 2C. This study opens a new avenue in the development of advanced sulfur hosts for lithium‑sulfur batteries.

Suppressing shuttle effect of polysulfides by yttrium hydroxide nanoarchitecture for stable lithium‑sulfur batteries

Rechargeable lithium–sulfur (Li–S) batteries reveal promising prospect as high energy storage systems because of the extraordinary theoretical specific energy density. However, the shuttle effect and sluggish reaction kinetics of polysulfides hamper the commercialization applications of high energy density Li-S batteries. Herein, a novel and efficient sulfur host material of yttrium hydroxide (Y(OH)3) has rationally been achieved for Li–S batteries. Y(OH)3 host not only suppress shuttle effect of polysulfides by physical confinement and chemisorption, but also decline Li2S nucleation and deposition reaction barriers and expedite chemical reaction kinetics. Consequently, the prepared Y(OH)3/S cathodes achieve a high initial specific capacity of 1295 mAh g−1 at 0.1 C and improved cycling stability with a low capacity decay rate of 0.019% per cycle over 1000 cycles at 2.0 C. The enhanced performances confirm a potential host material for facilitating practical implementation of Li–S batteries.

Facile preparation of gold nanoparticles anchored on layered yttrium hydroxide by electrochemical methods for enhanced sensing of hydroquinone and catechol

Gold nanoparticles (AuNPs) have emerged as highly competitive catalysts. However, the precise regulation of intrinsic structural parameters that account for the activity of AuNPs remains a challenge in designing high-performance electrocatalysts. Herein, the layered yttrium hydroxide (LYH) nanosheets supported AuNPs are prepared via a facile electrochemical deposition method. The tunability of morphology in LYH support and their utilization in controlling the growth of small AuNPs with uniform dispersion are emphasized. Finally, a novel sensor is constructed using flower-like AuNPs/LYH modified electrodes, which allows for simultaneous determination of the dihydroxybenzene isomers hydroquinone and catechol with good sensitivity, reproducibility and stability. The excellent performance can be attributed to the synergistic effects between AuNPs and LYHs. The strategy of depositing gold onto LYH nanosheets and the resulting high performance provide new approaches for further developing highly efficient composite electrodes across a wide range of applications.

Inclusion/energy transfer/release of L-ascorbate in the interlayer gallery of layered yttrium hydroxide

L-ascorbate (AS, Vitamin C) was intercalated into the interlayer gallery of layered yttrium hydroxide (LYH), a representative member of the layered rare earth hydroxide series (LRHs), through an ion-exchange reaction in an aqueous solution of sodium ascorbate. Based on the expansion of the interlayer space of the resulting AS-LYH hybrid, it is suggested that AS anions vertically oriented to hydroxide layers would be arranged to form a partially interdigitated bilayer in the interlayer space of LYH with a high loading capacity and density of AS. This arrangement is different from the antiparallel monolayer configuration of AS anions that are horizontally or vertically oriented to the layer of classical layered double hydroxides (LDHs). The durability of AS against light and oxidation was sufficiently enhanced in the interlayer gallery of LYH so that no degradation occurred after exposure to simulated sunlight or heating at 60 °C for a long time. Practically no release of AS from AS-LYH was observed in a saline solution and simulated sea water, whereas a sustained release of AS occurred selectively in a phosphate buffer solution, with a release process best described by the first-order model. When LYH was doped with Tb3+ activator to give it photoluminescence ability, the UV light energy absorbed for the π → π* transition of AS was efficiently transferred to Tb3+, leading to strong green emission attributed to its 5D4 → 7F5 transition.

Cinnamate-Intercalated Layered Yttrium Hydroxide: UV Light-Responsive Switchable Material.

In recent years, there has been an increasing interest in stimuli-responsive host-guest materials due to the high potential for their application in switchable devices. Light is the most convenient stimulus for operating these materials; a light-responsive guest affects the host structure and the functional characteristics of the entire material. UV-transparent layered rare earth hydroxides intercalated with UV-switchable anions are promising candidates as stimuli-responsive host-guest materials. The interlayer distance in the layered rare earth hydroxides depends on the size of the intercalated anions, which could be changed in situ, e.g., via anion isomerisation. Nevertheless, for layered rare earth hydroxides, the possibility of such changes has not been reported yet. A good candidate anion that is capable of intercalating into the interlayer space is the cinnamate anion, which undergoes UV-assisted irreversible trans-cis isomerisation. In this work, both trans- and cis-cinnamate anions were intercalated in layered yttrium hydroxide (LYH). Upon UV-irradiation, the interlayer distance of trans-cinnamate-intercalated layered yttrium hydroxide suspended in isopropanol changed from 21.9 to 20.6 Å. For the first time, the results obtained demonstrate the possibility of using layered rare earth hydroxides as stimuli-responsive materials.

Ultra-rapid fluoride removal by magnetic calcium-doped layered yttrium hydroxides at environmental-relevant concentrations

Currently, there is still a lack of strategies for rapid removal of fluoride at environmental-relevant concentrations. In this study, in which several magnetic calcium doped layered yttrium hydroxides (γ-Fe2O3/Ca-Y LRHs) modified with γ-Fe2O3 were synthesized and used for fluoride removal. The magnetic and adsorption properties analysis indicated γ-Fe2O3/4Ca-Y LRHs demonstrated performance of magnetism and adsorption ability. According to the pseudo-second-order and Langmuir models, the equilibrium time and maximum monolayer adsorption capacity of γ-Fe2O3/4Ca-Y LRHs was 2 min and 43.98 ± 2.34 mg/g, respectively. The adsorption and desorption studies revealed electrostatic and ion exchange interactions are involved in the defluorination mechanism, and chloride and oxygenated groups in interlayer spaces were the main ligands for fluoride exchanged. The potential applications on surface water demonstrate that the ability of γ-Fe2O3/4Ca-Y LRHs to remove fluoride at environmental-relevant concentrations. These findings are expected to facilitate the process of rapid removal of fluoride contamination in the aqueous environment.

Detection of human serum albumin using a rare-earth nanosheet fluorescent probe based on intensity and lifetime signals

Human serum albumin (HSA) is an important biomarker for early disease diagnosis. Therefore, the detection of HSA in biological samples is important. In this study, for the sensitive detection of HSA, a fluorescent probe based on Eu(III)-doped yttrium hydroxide nanosheets was designed and sensitized by α-thiophenformyl acetone trifluoride as an antenna. The morphology and structure of the as-prepared nanosheet fluorescent probe were studied by transmission electron microscopy and atomic force microscopy. A detailed investigation of the fluorescence properties of the as-obtained nanosheet probe revealed that the Eu(III) emission intensity was linearly and selectively enhanced by the consecutive addition of HSA. Furthermore, the lifetime signal of this probe was enhanced with increasing concentration. The sensitivity of the nanosheet probe to HSA is discussed based on the results of ultraviolet–visible, fluorescence, and infrared spectral analyses, the findings demonstrate that the nanosheet fluorescent probe we prepared is a highly sensitive and selective tool for detecting HSA concentration with a high intensity and a large lifetime change.

Energy absorption and transfer behavior of guest benzoate sensitizers in the interlayer space of Tb3+-doped layered yttrium hydroxide host

Energy absorption and transfer behavior of guest benzoate sensitizers in the interlayer space of Tb3+-doped layered yttrium hydroxide host

Innovative calcium-doped layered yttrium hydroxides for rapid and efficient removal of fluoride from aqueous solutions: Insight into adsorption mechanism

Fluoride contamination is an important problem for sustainable human development and has to be addressed by environmental governance. However, the rapid and efficient removal of fluoride from aqueous solutions has always been challenging. In this study, several calcium-doped layered yttrium hydroxides (Ca-Y LRHs) were synthesized and used to remove fluoride. Relative to other adsorbents, 6% Ca-Y LRHs exhibits excellent performance of adsorption equilibrium time and maximum monolayer adsorption capacity with 4 min and 125.54 mg/g, respectively, determined by the adsorption kinetics and Langmuir model. The remarkable removal ability is probably attributed to the high fraction of nitrate anions in the interlayer space, which instead of hydroxyl groups or OH-, can be replaced by fluoride, inhibiting the rise of pH in solution. The ions adsorption and detection analysis indicated electrostatic and ion exchange interactions are involved in the defluorination process, and oxygenated groups in interlayer spaces were the main ligands to be replaced by fluoride. Studies on potential applications were successfully conducted on wastewater of an electrochemical fluorination process and surface water, demonstrating the ability of 6% Ca-Y LRHs to remove fluoride from these environments. These findings could provide an alternative strategy for the rapid and efficient treatment of fluoride contamination.

Preparation and application of yttrium oxide with a large specific surface area through moderate carbonation in the presence of carbon dioxide

Yttrium oxide with a large specific surface area (SSA) (hereafter called LSSA Y2O3) has high-porosity structure, relatively large interface, and relatively abundant active surface sites, and its optical, chemical and thermal stability properties are greatly improved compared with ordinary yttrium oxide. As a result, LSSA Y2O3 has been applied in various fields as a luminescent, catalytic, and adsorbent material, showing enormous market potential. This study creatively presents a process designed to prepare LSSA Y2O3 powders through moderate carbonation in the presence of CO2. Experimentally, CO2 was used to carbonate a yttrium hydroxide [Y(OH)3] slurry. During the initial stage of carbonation, crystalline yttrium carbonate encapsulated Y(OH)3 through heterogeneous nucleation on its surface. This encapsulation considerably improved the filterability of the carbonation product while allowing it to retain the phase structure and high-porosity morphology of Y(OH)3. Further calcination of the carbonation product produced LSSA Y2O3 with an SSA of approximately 84 m2/g. This Y2O3 powder exhibited a relatively high adsorption capacity for methyl orange and was easy to recycle and reuse, thus showing potential for use as an adsorbent. The process developed in this study for preparing LSSA Y2O3 powders through carbonation in the presence of CO2 is advantageous because it requires only moderate conditions, causes no pollution, produces products with a uniform granularity and morphology, and is easy to scale up to meet industrial demands. Therefore, this process can effectively increase the added value and market competitiveness of Y2O3 powders and provide an experimental basis and theoretical guidance for the synthesis of other rare earth (RE) compounds with large SSAs through carbonation.

Spectroscopic, structural and thermal study of Y(OH)3microstructures synthesized by hydrothermal method: effect of the reaction time

Rare earth hydroxides have a wide variety of applications due to their interesting optical and magnetic properties. Specifically, yttrium hydroxide Y(OH)3 is an essential compound of rare earth hydroxides that can be used in areas such as electronics and chemistry due to its optical and structural properties. In this work Y(OH)3 was synthesized under nine reaction times (2–24 h) using the hydrothermal method in order to analyze the morphology evolution process that the Y(OH)3 follow to obtain the expected bar morphology. Also, a characterization study of Y(OH)3 through several techniques such as x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, infrared, Raman and UV-Vis spectroscopy, thermogravimetric analysis, and differential scanning calorimetry is presented. The obtained samples in every reaction time were compared on phase purity, particle size and shape, and spectroscopic and thermal properties. It was concluded that the reaction time has an important effect in obtaining yttrium hydroxide using the hydrothermal method. During the study, the optimal time to obtain only Y(OH)3 was evaluated, as well as the evolution of the morphology over time. At 12 hours, only Y(OH)3is obtained, therefore this time is proposed as the optimal time.