CrystEngComm最新文献

Anode materials are crucial for the advancement of high-performance sodium-ion batteries, with metal sulfides (MSs) emerging as particularly promising candidates owing to their substantial theoretical capacities (e.g., FeS₂ offers a capacity of up to 892 mAh g⁻¹). These materials have gained considerable attention as potential anodes for SIBs. While existing reviews have largely addressed the influence of structural features on performance, limited focus has been placed on the broad variety of MSs and their unique properties. This review provides a concise overview of the common synthesis methods for MSs used as high-performance anodes in SIBs, with a focus on hydrothermal/solvothermal, calcination and electrospinning techniques. Different morphologies and structures can be constructed using these methods. The hydrothermal/solvothermal method is carried out at a lower temperature, while the calcination method yields MSs with higher crystallinity. In addition, electrospinning enables the formation of MSs with a three-dimensional cross-linked structure. The choice of method can be tailored depending on the desired morphology. At the end of this review, recent research advancements in the field are highlighted, addressing the technological challenges and exploring promising research prospects for MSs and their future development.

Morphology is a critical factor that defines the properties and functions of nanomaterials. For gold (Au) nanostructures, branched morphological features have been proven to be beneficial in improving their properties and expanding their potential application domains. One notable example are Au nanocorals, whose elaborate hyperbranched architecture has been shown to result in enhanced performance in SERS-based detection, fluorescence imaging, and catalysis. However, due to their complex morphological design, their fabrication often necessitates complicated synthetic procedures, long reaction times, and harsh and/or expensive reagents. In this work, we present an alternative synthetic approach by which Au nanocorals are conveniently and rapidly produced in water under ambient conditions using low-cost biogenic acids. Through systematic evaluation of select biogenic acids, the key functional groups that are instrumental in the formation of a hyperbranched architecture were identified. From the results of our study, we were able to build a list of biogenic reagents (ascorbic acid, oxalic acid, gallic acid, protocatechuic acid, and succinic acid) that can be employed for the green and facile production of Au nanocorals. The ability to synthesize hyperbranched Au nanocorals using a simple, green, rapid, and economical approach is projected to spur further interest in these intricately designed materials and open up new avenues for their applications in various fields.

Lamotrigine (LAM) is a widely used first-line anti-epileptic drug with limitations due to its poor water solubility and side effects. Over the years, numerous attempts to modify LAM's physicochemical properties have been made, but the underlying reasons for the impact of newly formed salts on solubility remain unclear. This study aimed to address these issues by designing drug–drug salts of LAM with non-steroidal anti-inflammatory drugs (NSAIDs). The influence of structural factors on the pH-dependent solubility of LAM salts was investigated. Four novel drug–drug salts were successfully synthesized using flufenamic acid (FFA), diclofenac acid (DFA), mefenamic acid (MFA), and niflumic acid (NFA) as ligand molecules. The intrinsic dissolution rate and solubility of LAM and its corresponding salts were studied and compared to investigate the impact of structural factors on the pH-dependent solubility behavior. Results showed that the pH dependence of the newly formed salts decreased but did not alter the pH-dependent solubility tendency. Structural analysis revealed that O–H⋯O linked homodimers (LAM–LAM, FFA–FFA, DFA–DFA, MFA–MFA, NFA–NFA) exhibited a more stable spatial structure compared to N–H⋯O linked heterodimers (LAM–FFA, LAM–DFA, LAM–MFA, LAM–NFA). This stability led to a more stable arrangement of the salts and further reduced their solubility. In conclusion, this study provides valuable insights into the structural state of drug–drug salts and the effects of pH changes on their solubility.

TiO₂ nanocone structures (TNCs) have attracted tremendous interest in recent years owing to their intriguing physicochemical properties and potential applications in water purification-related fields. However, the controllable synthesis of high-quality vertically aligned TNCs with a specific phase is crucial for their effective application. Herein, we report the successful synthesis of heterophase TNCs with abundant active edge sites on a titanium foil by designing a glycerol-assisted hydrothermal approach. By tuning the growth parameters of the TNCs, their coverage can be tuned from 62% to 88% and their shapes can be tuned from sparse oblique to vertically aligned. In a photodegradation experiment, the photodegradation rate (K) of vertically aligned TNCs reaches ≈0.01985 min⁻¹, which is five times that of normal TiO₂ dense films (TDFs) under the same conditions, probably owing to their vertical and ordered nanocone array structures, which possess a large specific area, more active edge sites and efficient light harvesting. This work provides an efficient synthetic route for achieving vertically aligned heterophase TNCs, which can serve as perfect platforms for promoting their applications in photocatalytic fields.

Crystal structures of extended aromatic hydrocarbons are reviewed by applying the tools developed in my previous paper. Many large-area compounds have stacking (γ) structures, in which usually the longest edge with the maximum number of parallel peripheral hydrogen atoms forms the non-parallel (T-type) intercolumnar contact because the intermolecular energy is maximized due to the electrostatic attraction. The herringbone (HB) structure is regarded as the extreme limit. When the long edge is curved or blocked by substituents, a pitched π-stack structure is realized in which the molecular terminal forms the non-parallel contact. Since compounds with five-membered rings have tilted edges, unsymmetrical wedge-like molecules realize modified HB structures, but symmetrical molecules form a kind of stacking (θ) structure with a large dihedral angle of 130°. The stacking (γ) structure of large-area aromatic hydrocarbons is situated at the connecting point of the HB, pitched π-stack, and θ-structures because these structures have the same lattice symmetry.

Due to its excellent insulativity, thermal conductivity, chemical inertness and ultraflat surface, multilayer hexagonal boron nitride (h-BN) has become a favorable dielectric for two-dimensional materials or other conventional semiconductors. Multilayer h-BN can also serve as a functional material in deep ultraviolet optoelectronic or novel memory devices. However, the utilization of h-BN in electronic and optoelectronic applications has been severely impeded by the challenge of preparing large-area multilayer thin films. In this work, we achieved the controlled synthesis of centimeter-scale multilayer h-BN using a space confined route within an atmospheric pressure chemical vapor deposition (APCVD) system. Using thorough material characterization, the uniformity of multilayer h-BN is identified. We find that the thickness of multilayer h-BN can be fine-tuned with APCVD parameters and the growth mechanism in the confined space is systematically scrutinized. The multilayer h-BN thin film is further used as the gate dielectric for a hydrogen-terminated diamond field effect transistor (FET), which exhibits comparable performance with the devices with common dielectrics. Our work provides a novel strategy for the large-scale synthesis of multilayer h-BN thin films, paving the way for realizing its full potential in a panoply of applications.

The reaction of the NIT-2Py-3Py nitronyl nitroxide radical (NIT-2Py-3Py: 2-(2′,3′-bipyridine)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) containing two additional pyridine units with Ln(hfac)₃·2H₂O (hfac: hexafluoroacetylacetonate) gave rise to two one-dimensional chains [Ln(hfac)₃(NIT-2Py-3Py)]_n (Ln = Gd^III1, Nd^III2) and a trinuclear complex [Dy₃(hfac)₉(NIT-2Py-3Py)₂] (3). In complexes 1 and 2, the NIT-2Py-3Py radicals are ligated to the Ln^III ions in a “head-to-tail” mode to form zigzag chains. Complex 3 exhibits a linear trinuclear structure composed of one Dy(hfac)₃ with two coordinated pyridine groups and two {Dy^III–NIT radical} chelating units. Magnetic measurements indicate that the trinuclear Dy derivative shows magnetic relaxation characteristics, featuring an energy barrier of reversal of magnetization U_eff/k_B of 22.9 K.

A photosensitizing network was constructed via the linkage of Zr₆ clusters and an Ru(N^N)₃-metalloligand. It exhibited visible-light-driven photocatalytic activity for sulfide and amine oxidation with high efficiency and product selectivity. Reactive oxygen species (ROS) were studied via quenching experiments, and corresponding photocatalytic mechanisms were explored.

The significance of oxygen vacancies (OVs) as active catalytic sites in enhancing the photocatalytic hydrogen production capacity of BiVO₄ was investigated. We effectively introduced OVs into BiVO₄via a CTAB-assisted hydrothermal method, thereby significantly boosting its photocatalytic performance. We analyzed the underlying chemical mechanisms associated with CTAB's regulation of BiVO₄ crystal growth and clarified the precise process facilitating OV formation. The results revealed that OV integration profoundly enhanced BiVO₄'s charge transfer efficiency and conductivity, showing a remarkable 25-fold surge in the photocatalytic hydrogen production rate of the optimized sample (118.93 μmol g⁻¹ h⁻¹) compared to unmodified BiVO₄. Further analyses emphasized the critical role of OV stability within the BiVO₄ crystal structure in improving the catalytic hydrogen production performance. This work exhibits the pivotal function of OVs in amplifying BiVO₄'s photocatalytic hydrogen production potential and offers fresh modification strategies and theoretical foundations for developing high-performance BiVO₄-based photocatalysts.

Rational design of viable routes to develop affordable and efficient oxygen evolution reaction (OER) catalysts is essential for advancing electrochemical water splitting, yet significant challenges remain, particularly in seawater. Here, we propose a ligand defect engineering strategy to modify the electronic structure of NH₂-MIL-88B(Fe) using a monodentate ligand (acetic acid, AcOH), inducing ligand vacancies in NH₂-MIL-88B(Fe) for oxygen evolution in an alkaline seawater electrolyte, thereby improving the performance of the electrocatalysts. The resulting defective MOFs (denoted as NH₂-MIL-88B(Fe)-x) exhibited exceptionally high catalytic activity for OER, requiring low overpotentials of 313 and 329 mV at a current density of 100 mA cm⁻² in 1 M KOH and simulated seawater (1 M KOH + 0.5 M NaCl) solutions, respectively. Experimental analyses revealed that the introduction of AcOH can modulate the d-band center of active sites in NH₂-MIL-88B(Fe)-x and play a critical role in alleviating chloride ion (Cl⁻) corrosion, thereby enhancing catalytic stability in seawater. When directly used as an OER catalyst in an alkaline electrolyte, wind and solar power were harnessed to operate the NH₂-MIL-88B(Fe)-x || Pt/C configuration to drive the electrolytic water reaction. Thus, the ligand defect strategy can be employed to design and prepare high-performance OER electrocatalysts, particularly for generating H₂ through water electrolysis powered by renewable energy sources.