Search Results (42)

This study presented a novel reservoir computing (RC) system based on polymer electrolyte-gated MoS₂ transistors. The proposed transistors operate through lithium ion (Li⁺) intercalation, which induces reversible phase transitions between semiconducting 2H and metallic 1T’ phases in MoS₂ films. This mechanism enables dynamic conductance modulation with inherent nonlinearity and fading memory effects, rendering these transistors particularly suitable as reservoir nodes. Our RC implementation leverages time-multiplexed virtual nodes to reduce physical component requirements while maintaining rich temporal dynamics. Testing on a spoken digit recognition task using the NIST TI-46 dataset demonstrated 95.1% accuracy, while chaotic time-series prediction of the Lorenz system achieved a normalized root mean square error as low as 0.04. This work established polymer electrolyte-gated MoS₂ transistors as promising building blocks for efficient RC systems capable of processing complex temporal patterns, offering enhanced scalability, and practical applicability in neuromorphic computation. Full article

This research highlights the different behaviors of titanium (Ti) wires under the action of 500 W and 800 W microwave power levels. Following the interaction between microwaves and a titanium wire placed in the node of the (TM₀₁₁—transverse magnetic mode) waveguide in air at atmospheric pressure, plasma was generated. Using optical emission spectroscopy technique it was observed that during plasma generation at 500 W and 800 W microwaves powers, metallic ions, and gas ions were created, and the plasmas fulfilled the local thermodynamic equilibrium (LTE) conditions. The XRD analysis showed that on the surface of the Ti wire exposed to 500 W microwave power a mixture of titanium dioxide (TiO₂) and titanium oxide (TiO) grew, while the Ti wire exposed to 800 W microwave power was completely vaporized and a mixture of TiO₂ and TiO nanoparticles was synthesized. The SEM analysis showed that the dimensions of the titanium oxide (TiO_x) nanoparticles generated by both microwave discharges ranged from 5 nm to 200 nm. The results of EDS analysis showed that the power of microwaves plays an important role in quantitative conversion from Ti wire into a TiO_x mixture. The TEM analysis indicates that most of the nanoparticles are either amorphous or nanocrystalline. Using this simple and inexpensive technique one can grow a TiO_x layer on the surface of titanium electrodes or can synthetize nanocrystalline TiO_x particles. Full article

Metal–organic frameworks (MOFs) are also known as porous coordination polymers. This kind of material is constructed with inorganic nodes (metal ions or clusters) with organic linkers and has emerged as a promising class of materials with several unique properties. Well-known applications of MOFs include their use as gas storage and in separation, catalysis, carbon dioxide capture, sensing, slender film gadgets, photodynamic therapy, malignancy biomarkers, treatment, and biomedical imaging. Over the past 15 years, an increasing amount of research has been directed to MOFs due to their advanced applications in fuel cells, supercapacitors, catalytic conversions, and drug delivery systems. Various synthesis methods have been proposed to achieve MOFs with nanometric size and increased surface area, controlled surface topology, and chemical activity for industrial use. In this context, the pharmaceutical industry has been watching the accelerated development of these materials with great attention. Thus, the objective of this work is to study the synthesis, characterization, and toxicity of MOFs as potential technological excipients for the development of drug carriers. This work highlights the use of MOFs not only as delivery systems (DDSs) but also in advanced diagnostics and therapies, such as photodynamic therapy and targeted delivery to tumors. Bibliometric analyses showed a growing interest in the topic, emphasizing its contemporary relevance. Full article

The use of chiral organic ligands as linkers and metal ion nodes with specific coordination geometry is an effective strategy for creating homochiral structures with potential ferroelectric properties. Natural Cinchona alkaloids, e.g., quinine and cinchonine, as compounds with a polar quinuclidine fragment and aromatic quinoline ring, are suitable candidates for the construction of molecular ferroelectrics. In this work, the compounds [CnZnCl₃]·MeOH and [CnZnBr₃]·MeOH, which crystallize in the ferroelectric polar space group P2₁, were prepared by reacting the cinchoninium cation (Cn) with zinc(II) chloride or zinc(II) bromide. The structure of [CnZnBr₃]·MeOH was determined from single-crystal X-ray diffraction analysis and was isostructural with the previously reported chloride analog [CnZnCl₃]·MeOH. The compounds were characterized by infrared spectroscopy, and their thermal stability was determined by thermogravimetric analysis and temperature-modulated powder X-ray diffraction experiments. The intermolecular interactions of the different cinchoninium halogenometalate complexes were evaluated and compared. Full article

Tuning a material’s hydrophobicity is desirable in several industrial applications, such as hydrocarbon storage, separation, selective CO₂ capture, oil spill cleanup, and water purification. The introduction of fluorine into rare-earth (RE) metal–organic frameworks (MOFs) can make them hydrophobic. In this work, the linker bis(trifluoromethyl)terephthalic acid (TTA) was used to make highly fluorinated MOFs. The reaction of the TTA and RE³⁺ (RE: Y, Gd, or Eu) ions resulted in the primitive cubic structure (pcu) exhibiting RE dimer nodes (RE-TTA-pcu). The crystal structure of the RE-TTA-pcu was obtained. The use of the 2-fluorobenzoic acid in the synthesis resulted in fluorinated hexaclusters in the face-centered cubic (fcu) framework (RE-TTA-fcu), analogous to the UiO-66 MOF. The RE-TTA-fcu has fluorine on the linker as well as in the cluster. The MOFs were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, and contact angle measurements. Full article

Using quantum chemical calculation data obtained by the DFT method with the B3PW91/TZVP and M062X/def2TZVP theory levels, the possibility of the existence of four Be(II) coordination compounds, each of which contains in the inner coordination sphere and the double deprotonated forms of subporphyrazine (H₂SP), mono[benzo]subporphyrazine (H₂MBSP), di[benzo]subporphyrazine (H₂DBSP), and tri[benzo]subporphyrazine (subphthalocyanine) (H₂TBSP) with a ratio Be(II) ion/ligand = 1:1, were examined Selected geometric parameters of the molecular structures of these (666)macrotricyclic complexes with closed contours are given; it was noted that BeN3 chelate nodes have a trigonal–pyramidal structure and exhibit a very significant (almost 30°) deviation from coplanarity; however, all three 6-membered metal-chelate and three 5-membered non-chelate rings in each of these compounds are practically planar and deviate from coplanarity by no more than 2.5°. The bond angles between two nitrogen atoms and a Be atom are equal to 60° (in the [BeSP] and [BeTBSP]) or less by no more than 0.5° (in the [BeMBSP] and [BeDBSP]). The presence of annulated benzo groups has little effect on the parameters of the molecular structures of these complexes. Good agreement between the structural data obtained using the above two versions of the DFT method was noticed. NBO analysis data for these complexes are presented; it was noted that, according to both DFT methods used, the ground state of the each of complexes under study is a spin singlet. Standard thermodynamic parameters of formation (standard enthalpy Δ_fH⁰, entropy S⁰, and Gibbs free energy Δ_fG⁰) for the above-mentioned macrocyclic compounds were calculated. Full article

Covalent organic frameworks (COFs) are constructed from small organic molecules through reversible covalent bonds, and are therefore considered a special type of polymer. Small organic molecules are divided into nodes and connectors based on their roles in the COF’s structure. The connector generally forms reversible covalent bonds with the node through two reactive end groups. The adjustment of the length of the connector facilitates the adjustment of pore size. Due to the diversity of organic small molecules and reversible covalent bonds, COFs have formed a large family since their synthesis in 2005. Among them, a type of COF containing redox active groups such as –C=O–, –C=N–, and –N=N– has received widespread attention in the field of energy storage. The ordered crystal structure of COFs ensures the ordered arrangement and consistent size of pores, which is conducive to the formation of unobstructed ion channels, giving these COFs a high-rate performance and a long cycle life. The voltage and specific capacity jointly determine the energy density of cathode materials. For the COFs’ cathode materials, the voltage plateau of their active sites’ VS metallic lithium is mostly between 2 and 3 V, which has great room for improvement. However, there is currently no feasible strategy for this. Therefore, previous studies mainly improved the theoretical specific capacity of the COFs’ cathode materials by increasing the number of active sites. We have summarized the progress in the research on these types of COFs in recent years and found that the redox active functional groups of these COFs can be divided into six subcategories. According to the different active functional groups, these COFs are also divided into six subcategories. Here, we summarize the structure, synthesis unit, specific surface area, specific capacity, and voltage range of these cathode COFs. Full article

Bimetallic coordination polymers (CPs) have two different metal ions as connecting nodes in their polymer structure. The synthesis methods of bimetallic CPs are mainly categorized into the one-pot method and post-synthesis modifications according to various needs. Compared with monometallic CPs, bimetallic CPs have synergistic effects and excellent properties, such as higher gas adsorption rate, more efficient catalytic properties, stronger luminescent properties, and more stable loading platforms, which have been widely applied in the fields of gas adsorption, catalysis, energy storage as well as conversion, and biosensing. In recent years, the study of bimetallic CPs synergized with cancer drugs and functional nanomaterials for the therapy of cancer has increasingly attracted the attention of scientists. This review presents the research progress of bimetallic CPs in biosensing and biomedicine in the last five years and provides a perspective for their future development. Full article

The efficient synthesis of nanosheets containing two metal ions is currently a formidable challenge. Here, we attempted to dope lanthanide-based bimetals into porphyrin-based metal-organic skeleton materials (MOFs) by microwave-assisted heating. The results of the EDX, ICP, and XPS tests show that we have successfully synthesized porphyrin-based lanthanide bimetallic nanosheets (Tb-Eu-TCPP) using a household microwave oven. In addition, it is tested and experimentally evident that these nanosheets have a thinner thickness, a larger BET surface area, and higher photogenerated carrier separation efficiency than bulk porphyrin-based bimetallic materials, thus exhibiting enhanced photocatalytic activity and n-type semiconductor properties. Furthermore, the prepared Tb-Eu-TCPP nanomaterials are more efficient in generating single-linear state oxygen under visible light irradiation compared to pristine monometallic nanosheets due to the generation of bimetallic nodes. The significant increase in catalytic activity is attributed to the improved separation and transfer efficiency of photogenerated carriers. This study not only deepens our understanding of lanthanide bimetallic nanosheet materials but also introduces an innovative approach to improve the photocatalytic performance of MOFs. Full article

Metal-organic frameworks (MOFs) are a novel category of porous crystalline materials with an exceptionally high surface area and adjustable pore structure. They possess a designable composition and can be easily functionalized with different units. Porphyrins with conjugated tetrapyrrole macrocyclic structures can absorb light from ultraviolet to visible light regions, and their structures and properties can be facilely regulated by altering their peripheral groups or central metal ions. Porphyrin-based MOFs constructed from porphyrin ligands and metal nodes combine the unique features of porphyrins and MOFs as well as overcoming their respective limitations. This paper reviewed the design and construction, light absorption and charge transfer pathways, and strategy for improving the photocatalytic performance of porphyrin-based MOFs, and highlighted the recent progress in the field of CO₂ reduction, hydrogen evolution, organic synthesis, organic pollutant removal, and nitrogen fixation. The intrinsic relationships between the structure and the property of porphyrin-based MOFs received special attention, especially the relationships between the arrangements of porphyrin ligands and metal nods and the charge transfer mechanism. We attempted to provide more valuable information for the design and construction of advanced photocatalysts in the future. Finally, the challenges and future perspectives of the porphyrin-based MOFs are also discussed. Full article

A binary, three-dimensional (3D), foldable, Metal–Organic Framework (MOF) of formula {[trans-Ni(H₂O)₂(μ-4,4′-bpy)₂](ClO₄)₂}_n (1), with CdSO₄ (6⁵ 8), cds, topology, based on four-connected (4-c) square-planar single Ni²⁺ ion nodes and two-connected (2-c) linear rigid 4,4′-bipyridine (4,4′-bpy) ligands, was synthesized and structurally characterized via single crystal X-ray crystallography. The 41° dihedral angle between two distinct coordination environments within the 3D network of 1 produced the self-dual topology of Ni²⁺ nodes. Two rectangular 1D channels ran parallel to the crystallographic a-axis and b-axis, respectively, creating a 44.2% volume porosity, probed by gas (N₂, CO₂, and H₂) sorption studies. The PXRD, FT-IR, Raman, EDS, and SEM methods were employed for the study of 1. A thermogravimetric analysis (TGA) showed that coordinated water molecules were readily removed upon heating, whereas the 3D lattice remained intact up to 370 °C. Full article

A two-dimensional (2D) lamellar Zn metal–organic framework (Zn-MOF, 1) with a fluorescent 1,6-di(pyridin-3-yl)pyrene (3-DPPy) and 1,4-benzenedicarboxylate (BDC²⁻) bridging linkers was prepared and structurally characterized. The chemical formula of 1 is [Zn(μ-3-DPPy)(μ-BDC)]_n. The mononuclear Zn(II) ion, acting as a node, is tetrahedrally coordinated with two 3-DPPy and two BDC linkers. The coordination environment of Zn(II) is a distorted tetrahedral geometry. The Zn-MOF is the sql network structure based on topology analysis. The undulated 2D sheets of 1 tightly pack together to form a lamellar structure. The pyrene moieties are parallelly oriented to each other. The Zn-MOF is not porous, possibly because the mononuclear Zn(II) node did not form cluster-based secondary building units due to the less symmetric 3-DPPy. The steady-state fluorescence measurements indicate that the fluorescence signal of the 1 is slightly blue-shifted compared to the free 3-DPPy in the solid state. The excimer emission band at 463 nm for crystalline 3-DPPy is shifted to 447 nm for 1. The value of 447 nm is also a blue-shift value compared to nonsubstituted pyrene crystals (470 nm). Despite its nonporosity, the surface Lewis acidic sites of 1 could catalyze the transesterification of esters. Surface defect sites are responsible for this catalytic activity. Full article

Aqueous zinc ion batteries (AZIBs) are considered as one of the most promising energy storage technologies due to their advantages of being low in cost, high in safety, and their environmental friendliness. However, dendrite growth and parasitic side reactions on the zinc metal anode during cycling lead to a low coulombic efficiency and an unsatisfactory lifespan, which seriously hinders the further development of AZIBs. In this regard, metal–organic frameworks (MOFs) are deemed as suitable surface modification materials for the Zn anode to deal with the abovementioned problems because of their characteristics of a large specific surface area, high porosity, and excellent tunability. Considering the rapidly growing research enthusiasm for this topic in recent years, herein, we summarize the recent advances in the design, fabrication, and application of MOFs and their derivatives in the surface modification of the zinc metal anode. The relationships between nano/microstructures, synthetic methods of MOF-based materials, and the enhanced electrochemical performance of the zinc metal anode via MOF surface modification are systematically summarized and discussed. Finally, the existing problems and future development of this area are proposed. Full article

The insulin-like growth factor (IGF)/insulin signaling (IIS) pathway is involved in cellular responses against intracellular divalent manganese ion (Mn²⁺) accumulation. As a pathway where multiple nodes utilize Mn²⁺ as a metallic co-factor, how the IIS signaling patterns are affected by Mn²⁺ overload is unresolved. In our prior studies, acute Mn²⁺ exposure potentiated IIS kinase activity upon physiological-level stimulation, indicated by elevated phosphorylation of protein kinase B (PKB, also known as AKT). AKT phosphorylation is associated with IIS activity; and provides direct signaling transduction input for the mammalian target of rapamycin complex 1 (mTORC1) and its downstream target ribosomal protein S6 (S6). Here, to better define the impact of Mn²⁺ exposure on IIS function, Mn²⁺-induced IIS activation was evaluated with serial concentrations and temporal endpoints. In the wild-type murine striatal neuronal line STHdh, the acute treatment of Mn²⁺ with IGF induced a Mn²⁺ concentration-sensitive phosphorylation of S6 at Ser235/236 to as low as 5 μM extracellular Mn²⁺. This effect required both the essential amino acids and insulin receptor (IR)/IGF receptor (IGFR) signaling input. Similar to simultaneous stimulation of Mn²⁺ and IGF, when a steady-state elevation of Mn²⁺ was established via a 24-h pre-exposure, phosphorylation of S6 also displayed higher sensitivity to sub-cytotoxic Mn²⁺ when compared to AKT phosphorylation at Ser473. This indicates a synergistic effect of sub-cytotoxic Mn²⁺ on IIS and mTORC1 signaling. Furthermore, elevated intracellular Mn²⁺, with both durations, led to a prolonged activation in AKT and S6 upon stimulation. Our data demonstrate that the downstream regulator S6 is a highly sensitive target of elevated Mn²⁺ and is well below the established acute cytotoxicity thresholds (<50 μM). These findings indicate that the IIS/mTORC1 pathways, in which Mn²⁺ normally serves as an essential co-factor, are dually responsible for the cellular changes in exposures to real-world Mn²⁺ concentrations. Full article

In recent years, graphene has received so much attention because of its superlative properties and its potential to revolutionize electronics, especially in VLSI. This study analyzes the effect of single-event upset (SEU) in an SRAM cell, which employs a metal-oxide semiconductor type graphene nano-ribbon field effect transistor (MOS-GNRFET) and compares the results with another SRAM cell designed using a PTM 10 nm FinFET node. Our simulations show that there is a change in the data stored in the SRAM after a heavy ion strike. However, it recovers from radiation effects after 0.46 ns for GNRFET and 0.51 ns for FinFET. Since the degradation observed in Q and Qb of GNRFET SRAM are 2.7X and 2.16X as compared to PTM nano-MOSFET, we can conclude that GNRFET is less robust to single effect upset. In addition, the stability of SRAM is improved by increasing the supply voltage V_DD. Full article