Crystal Growth & Design最新文献

This study explores the fabrication of yttrium iron garnet (YIG) single crystal fibers using the laser heated pedestal growth (LHPG) method with the experimental addition of B₂O₃. The incorporation of B₂O₃ facilitates the fiber fabrication process by lowering the required growth temperatures and likely modifying melt viscosity behavior, consistent with the established fluxing behavior of B₂O₃ and the comparative viscosity trend observed in the TMA-VFT analysis, thereby improving process efficiency while maintaining fiber quality. Structural characterization using EBSD and SC-XRD reveals a transition from polycrystalline to single-crystal behavior, with improved alignment along the [111] direction without altering the garnet structure. Magnetic measurements show increases in saturation magnetization in B₂O₃-assisted fibers. Three-dimensional anisotropy energy modeling, based on EBSD-derived Euler angles, indicates that the enhanced crystallinity and orientation contribute to reorientation of MCA energy distribution due to improved crystallographic alignment. Faraday rotation measurements show that the B₂O₃-assisted sample exhibits a rotation angle closer to reported values for high-quality YIG, suggesting improved phase purity and crystallographic quality. These findings demonstrate that B₂O₃-assisted LHPG growth is a scalable and nontoxic approach to producing high-performance YIG fibers for integrated photonic and magnetic field sensing applications.

The development of efficient photocatalytic materials is the key to promoting the advancement and application of photocatalytic technology. Bi₂S₃, a relatively narrow bandgap semiconductor, can absorb visible light and even near-infrared light. However, the fast recombination rate of photogenerated electron–hole pairs, limited surface active sites, and susceptibility to photocorrosion of pure Bi₂S₃ severely restrict its photocatalytic efficiency. In this paper, carbon-doped sulfur-rich defective hollow Bi₂S₃ nanorods were prepared in one step using Bi-MOF as the precursor. The microcrystalline structure and defect structure were regulated by adjusting the hydrothermal reaction time. The ammonia production rate of hollow Bi₂S₃-2 under full sunlight was approximately 147.78 μmol·h^–1·g^–1. The superior photocatalytic activity of hollow Bi₂S₃-2 is mainly attributed to its sulfur defects, which can provide abundant active sites to activate nitrogen molecules. It reveals that the photoexcited electrons generate ammonia through two protonation pathways and weaken the N≡N bond in the photocatalytic nitrogen fixation path. This work provides new insights into photocatalytic nitrogen fixation and achieves efficient N₂ photoreduction by synthesizing photocatalysts from MOF derivatives.

Lanthanide metal–organic frameworks (Ln-MOFs) have been widely applied in fluorescence detection due to their diverse structures and unique luminescence properties. In this work, two isostructural Ln-MOFs, namely, {[Ln₂(THBA)(H₂O)₄]·2H₂O}_n (Ln = Eu for Eu-MOF and Tb for Tb-MOF, H₆THBA = [1,1′4′,1″-terphenyl] −2′,3,3″,5,5′,5″-hexacarboxylic acid), were successfully synthesized and characterized. Fluorescence experiments demonstrate that Eu-MOF exhibits high sensitivity and selectivity toward malachite green (MG) and diphenylamine (DPA), with detection limits of 0.139 and 0.069 μM, respectively. Similarly, Tb-MOF also exhibits outstanding fluorescence sensing performance for MG and DPA, with detection limits of 0.089 and 0.094 μM, respectively. The fluorescent sensing films composed of Ln-MOFs@PMMA have been prepared by incorporating it into poly(methyl methacrylate) (PMMA), achieving rapid visual detection of MG and DPA. Moreover, highlighters with potential applications in anticounterfeiting were designed based on Eu-MOF and Tb-MOF.

Fe³⁺ and Hg²⁺ pose serious health risks, which necessitate dual-response sensors to monitor them. Herein, two new coordination polymers (CPs) [Cd(L)(1-NA)OH]_n (1) and [Cd(L)(9-AC)₂EtOH]_n (2) were synthesized using the 9,10-bis(di(pyridin-4-yl)methylene)-9,10-dihydroanthracene (L) bridging ligand and 1-NA/9-AC (1-Naphthoic acid/9-Anthracenecarboxylic acid) terminal ligands. 1-NA and 9-AC have different molecular sizes, which lead to distinct chain skeletons, π–π stacking, and porosities in 1 and 2. Three-connected L and [Cd(1-NA)OH] units link with each other to form a 1-D zigzag chain in 1, while L single bridges connect with [Cd(9-AC)₂EtOH] units to generate a 1-D linear chain in 2. Notably, photochromism-induced luminescence enables a dual-response sensing performance for 1 and 2. 1 exhibits “turn-on” and blueshifted Fe³⁺ sensing, which is the first instance reported among all CP-based Fe³⁺ sensors, while 2 has no obvious Fe³⁺ sensing ability. The sensing mechanism involves an Fe³⁺-triggered transformation from ligand-to-ligand charge transfer to a localized excitation process. Furthermore, 1′ and 2′ (1 and 2 after photochromism) can detect Hg²⁺ via a “turn-off” mechanism through a ligand-to-metal charge transfer process. 1′ exhibits more sensitive Hg²⁺ sensing performance than 2′. Specifically, 1′ achieves a remarkably low limit of detection (LOD: 9.16 nM). This work reveals the crucial role of terminal ligands in CP-based sensors.

Salt formation proved to be the most effective solid-state form for insoluble drugs in terms of improving solubility, crystallinity, stability, and/or bioavailability. A salt form of a drug where two ions of the same type are associated with one drug molecule further improves solubility and overall drug performance. However, a systematic comparison of these forms for a given drug combination remains scarce. This is achieved by the drug having at least two sites that can ionize, allowing it to form ionic bonds with a counterion. Osimertinib (OSTN), characterized by poor solubility and bioavailability, is a highly selective kinase inhibitor approved by the FDA, which is indicated for treatment of locally advanced or metastatic nonsmall cell lung cancer. In the present study, a multicomponent system based on OSTN’s diprotic base was prepared and characterized by various methods. This system comprises mono- and disalts derived from three sulfonic acids: methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Although the powder diffractions of OSTN mesylate (OSTN-MSA-A and OSTN-MSA-B) and OTSN tosilate (OSTN-TsOH) have been reported, and the crystal structure of OSTN-MSA-B was solved by using synchrotron X-ray powder diffraction data and optimized using density functional techniques, our study marks the inaugural report of their crystallographic structures. Three new solid forms (OSTN-BES, OSTN-2BES, and OSTN-2TsOH) were initially identified and subjected to a comprehensive characterization through thermal analysis, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) techniques, etc. In addition, their hygroscopicity and solubility were determined and compared, combining with the respective molecular conformation, their inter- and intramolecular interactions, and packing arrangement. Notably, OSTN disalt exhibited superior dissolution performance when compared to that of monosalt. The comparative study offers valuable guidance for the development of salt screening for insoluble drugs with two sites that can ionize.

Two isostructural three-dimensional metal–organic frameworks (MOFs), [Co(TTz)(IPA)]·0.5(TTz)·0.5H₂O (HC-1) and [Cd(TTz)(IPA)]·0.5(TTz)·H₂O (HC-2), were constructed via a dual-ligand strategy using ligands 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (TTz) and isophthalic acid (H₂IPA). Both MOFs display selective, intrinsic ratiometric fluorescence responses toward glutathione, arising from pronounced emission enhancement accompanied by red-shifted maxima, enabling selective and sensitive GSH detection with limits of detection of 1.28 μM for HC-1 and 0.30 μM for HC-2. Notably, the ratiometric response is achieved within single-component MOFs without the need for composite architectures. In addition, the materials display humidity-dependent proton conduction behavior. HC-1 achieves a high proton conductivity of 1.80 × 10^–4 S·cm^–1 at 98% relative humidity and 338 K, whereas HC-2 shows a much lower proton conductivity of 5.30 × 10^–6 S·cm^–1 under identical conditions. Comparative studies reveal that the metal ion plays a decisive role in regulating both fluorescence signaling and proton transport, despite minimal structural perturbation. These findings demonstrate that metal-ion identity serves as a decisive regulator of fluorescence signaling and proton conduction in isostructural MOFs, providing mechanistic insight into the design of multifunctional crystalline materials.

Drug–drug pharmaceutical multicomponent materials (PMMs) offer a promising strategy to modulate the physicochemical properties of active pharmaceutical ingredients, while enabling synergistic effects and combination therapy. Here, we report the preparation and full characterization of a new family of oxicam–metformin (MTF) salts, involving the nonsteroidal anti-inflammatory drugs piroxicam (PRX), meloxicam (MLX), and tenoxicam (TNX). Structural and computational studies revealed the role of supramolecular synthons in directing the salt formation and highlighted the relationship between molecular packing and physicochemical properties. Stability analyses showed that these materials enhance MTF stability, while particularly protecting PRX from hydration. Importantly, incorporation of MTF increased the aqueous solubility of the oxicams, while salt formation moderated the excessive solubility of free MTF. Significant modifications in fluorescence behavior were also observed, arising from interactions between functional groups involved in the fluorescence procedure within the frameworks. Overall, this study broadens the structural and functional landscape of oxicam–MTF salts and provides a rational framework for designing solid forms with improved stability and solubility.

Functional ceramics play a key role in technology, particularly in piezoelectric sensors and actuators, ferroelectric power generation, and durable semiconductors used in sensors and memristors. In this study, we report a versatile wet chemical synthesis approach, converting the surface of functional tetrapodal zinc oxide (t-ZnO) to common metal hydroxides. We performed structural, morphological, and interface characterization and explored the subsequent application of various t-ZnO@metal hydroxide/oxide core–shell structures. The t-ZnO core was initially uniformly coated with different metal hydroxides, forming distinct platelets in a core–shell architecture. Interface studies were conducted to investigate the chemical, structural, and morphological properties of these hybrid microstructures using 2D scanning nano X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), bulk XRD, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Our findings highlight the potential of exceptional t-ZnO structures as versatile templates, offering their morphology for the synthesis of derived oxides and hydroxides of many other elements while leveraging their structural advantages.

This review provides a comprehensive assessment of recent advancements in molecular simulation methodologies for hydrate-bearing sediments with a focus on innovations in molecular force field development and practical implementations. This review critically assesses how concurrent advancements in single-phase force fields, multiphase interfacial parametrization, and machine learning techniques synergistically improve the accuracy and predictive capability of molecular simulations for hydrate systems under varying geological conditions. Current molecular force fields face significant challenges when applied to hydrate-bearing sediments. These challenges include inaccurate phase transition predictions under extreme conditions. Parameter incompatibility between different phases causes errors in interfacial energy calculations. Computational efficiency and accuracy present fundamental trade-offs that limit large-scale applications. Experimental validation data for microscopic processes remain insufficient. Future research priorities encompass three strategic areas. Development of extreme condition-adaptable force fields will integrate quantum mechanical calculations with experimental data to optimize parameters for high-pressure, low-temperature environments. Machine learning techniques will enable multiphysics-coupled models that balance computational accuracy and efficiency for large-scale multiphase simulations. Collaborative experimental-simulation frameworks will establish high-resolution validation benchmarks across molecular to reservoir scales. These integrated approaches bridge nanoscale molecular phenomena with macroscale engineering applications, enabling effective natural gas hydrate exploitation and utilization.