Search Results (3,049)

Metal–organic frameworks (MOFs), formed by the self-assembly of metal ions/clusters and organic linkers, have attracted considerable attention due to their well-exposed active sites, exceptionally high porosity, and diversified pore architectures. MOF-derived materials obtained through high-temperature pyrolysis or composite structural design not only inherit the porous framework advantages of their precursors but also demonstrate significantly enhanced electrical conductivity and structural stability via the formation of carbon-based frameworks and in situ transformation of metallic species. However, conventional MOF-derived materials struggle to address persistent technical challenges in contemporary energy storage systems, particularly those requiring ultralong cycling stability and ultrahigh-rate capability under practical operating conditions. The integration of MXene, characterized by its abundant surface functional groups (-O, -OH, -F) and exceptional electrical conductivity, with MOF-derived materials presents a viable strategy to address these challenges. Multidimensional nanocomposites constructed through in situ growth and self-assembly techniques synergistically integrate MXene’s conductive network scaffolding effect with the structural tunability of MOF-derived frameworks. This unique architecture enables the following: (i) enhanced exposure of electroactive sites, (ii) optimized ion diffusion kinetics, (iii) mechanical integrity maintenance, collectively boosting the applicability of MXene/MOF hybrids in advanced energy storage systems. This review summarizes the synthesis methods, energy storage performance, and applications of multidimensional nanostructured MXene/MOF-derived composites. Finally, it discusses the opportunities and challenges for MXene/MOF-derived composites in future energy storage applications. Full article

Cu-based layered double hydroxides (LDH) have been extensively employed as catalyst precursors. However, due to the Jahn–Teller effect of copper ions, it is a challenge to synthesize well-crystallized LDH with a high Cu content, which usually contains considerable CuO impurity. By adding competitive ligands during the coprecipitation process, such as glycine, a well-crystallized Cu-rich LDH with less CuO impurity was successfully synthesized. The Cu-Mg-Al mixed oxides derived from the well-crystallized Cu-rich LDH have relatively high S_BET, large pore volume, and well dispersion of Cu nanoparticles. The derived catalyst exhibited unexpectedly high catalytic activity in the water–gas shift (WGS) reaction, and the mass-specific reaction rate was reached as high as 33.5 μmol_CO·g−1 cat·s⁻¹ at 200 °C. The high catalytic activity of this catalyst may originate from the high S_BET and well dispersion of Cu particles and metal oxides. Moreover, the derived catalyst also displayed outstanding long-term stability in the WGS reaction, which should benefit from the enhanced metal–support interaction. Full article

The widespread contamination of aquatic environments by tetracycline antibiotics (TCs) poses a substantial threat to public health and ecosystem stability. Although photo-Fenton processes have demonstrated remarkable efficacy in degrading TCs, their practical application is limited by challenges associated with catalyst recyclability. This study reports the development of a novel magnetic recoverable SrFe₁₂O₁₉/g-C₃N₄ heterostructure photocatalyst synthesized via a facile one-step co-calcination method using industrial-grade precursors. Comprehensive characterization revealed that nitrogen defects and the formation of heterojunction structures significantly suppress electron (e⁻)–hole (h⁺) pair recombination, thereby markedly enhancing catalytic activity. The optimized 7-SFO/CN composite removes over 90% of oxytetracycline (OTC) within 60 min, achieving degradation rate constants of 0.0393 min⁻¹, which are 9.1 times higher than those of SrFe₁₂O₁₉ (0.0043 min⁻¹) and 4.2 times higher than those of g-C₃N₄ (0.0094 min⁻¹). The effectively separated e⁻ play three critical roles: (i) directly activating H₂O₂ to generate ·OH radicals, (ii) promoting the redox cycling of Fe²⁺/Fe³⁺ ions, and (iii) reducing dissolved oxygen to form ·O₂⁻ species. Concurrently, h⁺ directly oxidize OTC molecules through surface-mediated reactions. Furthermore, the 7-SFO/CN composite exhibits exceptional operational stability and applicability, offering a transformative approach for scalable photocatalytic water treatment systems. This work provides an effective strategy for designing efficient and recoverable photocatalysts for environmental remediation. Full article

As high-quality sheep germplasm resources in China, Hu sheep are characterized by fast growth and development, high fecundity, and tolerance to drought and cold. Tibetan sheep, adapted to high-altitude environments, have developed strong environmental adaptability. To explore the differences in the interaction among rumen microbial flora, hepatic gluconeogenesis, and mitochondrial function between Tibetan sheep and Hu sheep in the Qinghai–Tibet Plateau, this study systematically compared and analyzed the rumen flora density, key enzyme activities related to hepatic gluconeogenesis and mitochondrial function, and the expression levels of related genes in Tibetan sheep and Hu sheep under identical feeding management conditions, followed by correlation analysis. The results showed that Hu sheep had significantly higher densities of Ruminobacteramylophilus (Ram) and Fibrobacter succinogenes (Fs) associated with starch and protein degradation (p < 0.01). The expression levels of Forkhead box O1 (FOXO1), pyruvate carboxylase (PC) activity, and adenosine triphosphate (ATP) content were also significantly higher than those in Tibetan sheep (p < 0.01). In contrast, Tibetan sheep had higher densities of Butyrivibrio fibrisolvens (Bf), Ruminococcus albus (Ra), Ruminococcus flavefaciens (Rf), etc., related to cellulose degradation (p < 0.01). The gluconeogenesis-related genes, Glucose-6-phosphatase catalytic subunit 1 (G6PC1) and phosphoenolpyruvate carboxykinase1 (PCK1), and the activities of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FBPase) were significantly higher in Tibetan sheep than in Hu sheep (p < 0.01). Mitochondrial function-related genes Mitofusin-1 (Mfn1), Mitofusin-2 (Mfn2), subunit 6 of ATP synthase (ATP6), cytochrome b (Cytb), etc., also showed significantly higher expression in Tibetan sheep (p < 0.01). While no significant differences were observed in the contents of citric acid (CA), pyruvic acid (PA), glucose (Glu), etc. (p > 0.05). Correlation analysis indicated that rumen flora was associated with the key enzyme activities and gene expressions of hepatic gluconeogenesis and mitochondrial function to varying degrees. In summary, Tibetan sheep exhibit strong fiber degradation capacity, the efficient utilization of gluconeogenic intermediates, and mitochondrial oxidative phosphorylation (OXPHOS) ability, forming adaptive strategies for high-altitude environments. By contrast, Hu sheep show efficient protein and starch degradation capacity, thereby enhancing the supply of gluconeogenic precursors. It is indicated that when introducing Hu sheep to high-altitude areas, dietary intervention can be used to regulate rumen microorganisms, such as increasing fiber-decomposing bacteria or enhancing mitochondrial oxidative capacity, to counteract metabolic limitations induced by hypoxia. Full article

Iron phosphate (FePO₄·2H₂O) was synthesized via anodic oxidation using nickel–iron alloy composition simulates from laterite nickel ore as the anode and graphite electrodes as the cathode, with phosphoric acid serving as the electrolyte. A uniform experimental design was employed to systematically optimize the synthesis parameters including voltage, electrolyte concentration, electrolysis time, and degree of acidity or alkalinity (pH). The results indicate that the addition of cetyltrimethylammonium bromide (CTAB) surfactant effectively modulated the morphology of the anodic oxidation products. The optimized conditions were determined to be an electrolyte concentration of 1.2 mol/L, a voltage of 16 V, a pH of 1.6, an electrolysis time of 8 h, and a 3% CTAB addition. Under these conditions, the synthesized FePO₄·2H₂O exhibited enhanced performance as a lithium-ion battery precursor. Specifically, the corresponding LiFePO₄/C cathode delivered an initial discharge capacity of 157 mA h g⁻¹ at 0.2 C, retaining 99.36% capacity after 100 cycles. These findings provide valuable insights and theoretical foundations for the efficient preparation of iron phosphate precursors, highlighting the significant impact of optimized synthesis conditions on the electrochemical performance of lithium iron phosphate. Full article

The textile industry encounters serious environmental challenges from wastewater with persistent organic pollutants, demanding sustainable solutions for remediation. Herein, we report a novel green synthesis of flexible BiOBr@PZT nanocomposite membranes via electrospinning and successive ionic layer adsorption and reaction (SILAR) for visible-light-driven photocatalytic degradation. The hierarchical structure integrates leaf-like BiOBr nanosheets with PAN/ZnO/TiO₂ (PZT) nanofibers, forming a Z-scheme heterojunction. This enhances the separation of photogenerated carriers while preserving mechanical integrity. SILAR-enabled low temperature deposition ensures eco-friendly fabrication by avoiding toxic precursors and cutting energy use. Optimized BiOBr@PZT-5 shows exceptional photocatalytic performance, achieving 97.6% tetracycline hydrochloride (TCH) degradation under visible light in 120 min. It also has strong tensile strength (4.29 MPa) and cycling stability. Mechanistic studies show efficient generation of O₂⁻ and OH radicals through synergistic light absorption, charge transfer, and turbulence-enhanced mass diffusion. The material’s flexibility allows reusable turbulent flow applications, overcoming rigid catalyst limitations. Aligning with green chemistry and UN SDGs, this work advances multifunctional photocatalytic systems for scalable, energy-efficient wastewater treatment, offering a paradigm that integrates environmental remediation with industrial adaptability. Full article

The gate reliability issues in SiC-based devices with a gate dielectric formed through heat oxidation are important factors limiting their application in power devices. Aluminum oxide (Al₂O₃) and titanium dioxide (TiO₂) were combined using the ALD process to form a composite AlTiO gate dielectric on a 4H-SiC substrate. TDMAT and TMA were the precursors selected and deposited at 200 °C, and the samples were Ar or N₂ annealed at temperatures ranging from 300 °C to 700 °C. An XPS analysis suggested that the AlTiO film had been deposited with a high overall quality and the involvement of Ti atoms had increased the interfacial bonding with the substrate. The as-deposited MOS structure had band shifts of ΔE_C = 1.08 eV and ΔE_V = 2.41 eV. After annealing, the AlTiO bandgap increased by 0.85 eV at most, and better band alignment was attained. Leakage current and breakdown voltage characteristic investigations were conducted after Al electrode deposition. The leakage current density and electrical breakdown field of an MOS capacitor structure with a SiC substrate were ~10⁻³ A/cm² and 6.3 MV/cm, respectively. After the annealing process, both the measures of the JV performance of the MOS capacitor had improved to ~10⁻⁶ A/cm² and 7.2 MV/cm. The interface charge N_eff of the AlTiO layer was 4.019 × 10¹⁰ cm⁻². The AlTiO/SiC structure fabricated in this work proved the feasibility of adjusting the properties of single-component gate dielectric materials using the ALD method, and using a suitable thermal annealing process has great potential to improve the performance of the compound MOS dielectric layer. Full article

Diseases caused by infection are a threat to human health and the world economy, with bacterial infections being responsible for a large portion of hospitalizations, morbidity, and mortality, which necessitates the quest for advanced medications and/or sustainable antibacterial strategies. This study aims to develop bioderived chitin nanofibers (ChNFs) and ZnO nanoparticles to produce non-toxic nanohybrid materials with improved aqueous stability and enhanced antibacterial properties. These nanohybrids were formed via either (i) an ex situ route by mixing the ChNFs with ZnO nanoparticles prepared by flame spray pyrolysis or (ii) an in situ route resulting in ZnO nanoparticles being formed and embedded into ChNFs by a simple aqueous hydrothermal process, utilizing a low-cost Zn inorganic precursor. The ChNFs, the ZnO nanoparticles, and the nanohybrids were physicochemically characterized for their size, morphology, charge and stability. Their antibacterial activity was evaluated against Gram (−) E. coli and Gram (+) S. aureus bacteria, while their cytocompatibility was assessed against mammalian cell lines. The obtained results reveal a balance between antibacterial activity and cytocompatibility, as both nanohybrids exhibited satisfactory antibacterial activity (MIC 200–300 μg/mL) combined with low cytotoxicity against mammalian cell lines (cell viability 80–100%), indicating that their further application as safe and effective antibacterial agents is promising. Full article

In this paper, we investigated fractal cluster structures of colloidal particles in tin dioxide films obtained from lyophilic film-forming systems SnCl₄/EtOH/NH₄OH with different pH levels. It was revealed that at the ratio Sn > Cl₂ > O₂, N₂ = 0, and pH = 1.42, the growth of cross-shaped and flower-shaped structures of various sizes from several μm to tens of μm is observed. At the ratio Cl₂ > Sn > O₂ > N₂ and pH = 1.44, triangular and hexagonal structures are observed, the sizes of which are on the order of several tens of micrometers. The growth of hexagonal structures is probably affected by the presence of nitrogen in the film, according to the elemental analysis data. At the ratio Sn > Cl₂ > O₂ > N₂ and solution pH of 1.49, the growth of hexagonal and cross-shaped structures is observed, whereas flower-shaped structures are not observed. Hierarchical flower-like and cross-shaped structures are fractal. The shape of microstructures is directly related to the shape of the elementary cells of SnO₂ and NH₄Cl. A direct dependence of the formation of hierarchical structures on the volume of ammonium hydroxide additive was found. This allows for controlling the shape and size of the synthesized structures when changing the ratio of the initial precursors and influencing the final physicochemical characteristics of the obtained samples. Full article

Background/Objectives: Nucleoside precursors and derivatives play pivotal roles in the development of antimicrobial and antiviral therapeutics. The 2022 global outbreak of monkeypox (Mpox) across more than 100 nonendemic countries underscores the urgent need for novel antiviral agents. This study aimed to synthesize and evaluate a series of 5′-O-(palmitoyl) derivatives (compounds 2–6), incorporating various aliphatic and aromatic acyl groups, for their potential antimicrobial activities. Methods: The structures of the synthesized derivatives were confirmed through physicochemical, elemental, and spectroscopic techniques. In vitro antibacterial efficacy was assessed, including minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations for the most active compounds (4 and 5). The antifungal activity was evaluated based on mycelial growth inhibition. Density functional theory (DFT) calculations were employed to investigate the electronic and structural properties, including the global reactivity, frontier molecular orbital (FMO), natural bond orbital (NBO), and molecular electrostatic potential (MEP). Molecular docking studies were conducted against the monkeypox virus and the Marburg virus. The top-performing compounds (3, 5, and 6) were further evaluated via 200 ns molecular dynamics (MD) simulations. ADMET predictions were performed to assess drug-likeness and pharmacokinetic properties. Results: Compounds 4 and 5 demonstrated remarkable antibacterial activity compared with the precursor molecule, while most derivatives inhibited fungal mycelial growth by up to 79%. Structure-activity relationship (SAR) analysis highlighted the enhanced antibacterial/antifungal efficacy with CH₃(CH₂)₁₀CO– and CH₃(CH₂)₁₂CO–acyl chains. In silico docking revealed that compounds 3, 5, and 6 had higher binding affinities than the other derivatives. MD simulations confirmed the stability of the protein-ligand complexes. ADMET analyses revealed favorable drug-like profiles for all the lead compounds. Conclusions: The synthesized compounds 3, 5, and 6 exhibit promising antimicrobial and antiviral activities. Supported by both in vitro assays and comprehensive in silico analyses, these derivatives have emerged as potential candidates for the development of novel therapeutics against bacterial, fungal, and viral infections, including monkeypox and Marburg viruses. Full article

In this research, an emerging, non-metallic photocatalyst was prepared by the thermal polymerization method from three different precursors: urea, melamine, and three mixtures of melamine and cyanuric acid. Graphitic carbon nitride (g-C₃N₄) samples from urea and melamine were synthesized in a muffle furnace at three different temperatures: 450°, 500°, and 550 °C for 2 h, while the samples made of a mixture of melamine and cyanuric acid (with mass ratios of 1:1, 1:2, and 2:1) were synthesized at 550 °C for 2 h. All the samples were characterized in order to determine their chemical and physical properties, such as crystallite size and structure, and phase composition by the following techniques: Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). Nitrogen adsorption/desorption isotherms were used to investigate the Brunauer, Emmett, and Teller (BET) specific surface area and Barrett–Joyner–Halenda (BJH) pore size distribution. Band gap values were determined by diffuse reflectance spectroscopy (DRS). Furthermore, adsorption and photocatalytic degradation of the local anesthetic drug procaine were monitored under UV-A, visible, and simulated solar irradiation in a batch reactor. Kinetic parameters, as well as photocatalytic mechanisms using scavengers, were determined and analyzed. The results of the photocatalysis experiments were compared to the benchmark TiO₂ Evonik Aeroxide P25. The results indicated that the g-C₃N₄ sample synthesized from urea at 500 °C for 2 h exhibited the highest degradation rate of procaine under visible light. Full article

Acrylamide (ACR), utilized as a precursor for producing polyacrylamide for water purification, has demonstrated neurotoxic properties. However, the mechanisms underlying its neurotoxicity remain inadequately understood. In this investigation, Caenorhabditis elegans were exposed to ACR at concentrations ranging from 250 to 1000 μg/mL and then their locomotor behavior, neuronal development, neurotransmitter concentrations, and gene expression profiles were assessed. Exposure to 250–1000 μg/mL ACR resulted in observable behaviors such as head swiveling and body bending, accompanied by a significant reduction in body size. Furthermore, ACR exposure caused damage to serotonergic, cholinergic, dopaminergic, and glutamatergic neuronal structures. In this context, elevated levels of serotonin, dopamine, acetylcholine, and glutamate were detected, along with notable upregulation of the expression of genes associated with neurotransmitters, including tph-1, cat-4, mod-1, mod-5, cat-1, ser-1, dat-1, dop-1, dop-3, unc-17, cho-1, eat-4, and glr-2. Moreover, ACR exposure elevated reactive oxygen species (ROS), O₂, and H₂O₂ levels while concurrently depleting glutathione (GSH), thereby compromising the antioxidant defense system. This led to a significant upsurge in the expression of genes involved in the nematode ACR detoxification pathway, specifically daf-16, skn-1, mlt-1, sod-3, gst-4, gcs-1, hsf-1, and hsp-16.2. Additionally, Spearman correlation analysis revealed a significant inverse relationship between certain neurotransmitter and antioxidant genes and locomotor activities, highlighting the role of these genes in mediating ACR-induced neurotoxicity in C. elegans. Collectively, this research enhances the understanding of the mechanisms related to ACR neurotoxicity. Full article

To address the challenge of abatement of volatile organic compounds (VOCs) in environmental catalysis, this study developed a temperature-gradient hydrothermal strategy to fabricate SrSn(OH)₆ nanocatalysts and systematically investigatd their photocatalytic performance and mechanisms for gaseous toluene degradation. SrSn(OH)₆ (SSH) was synthesized via a simple hydrothermal method with optimal preparation conditions identified as a reaction temperature of 140 °C and duration of 12 h. The crystallinity of SrSn(OH)₆ was modulated by adjusting the pH of the precursor solution, yielding materials with distinct morphologies, specific surface areas, and band gaps. The narrowed band gap of SrSn(OH)₆ nanocatalysts facilitated electron excitation to generate additional photogenerated electron-hole pairs. The SSH-10.5 sample with ordered planar and hole-like structures promoted carrier migration, effectively suppressed electron-hole recombination, and enhanced the conversion of abundant surface hydroxyl groups into hydroxyl radicals. Under UV irradiation, SSH-10.5 achieved a toluene degradation efficiency of 69.56% and showed excellent stability after five reuse cycles. Electron spin resonance analysis confirmed the presence of •OH and •O₂⁻ radicals in the reaction system, with •OH identified as the dominant active species. In situ FT-IR spectroscopy revealed that •OH and •O₂⁻ radicals attacked the methyl group of toluene, converting it into intermediates including benzyl alcohol, benzaldehyde, and benzoic acid. This work provides a novel design of high-efficiency VOC-photocatalytic materials and shows significant implications for advancing industrial exhaust gas purification technologies. Full article

Ammonia is a promising hydrogen storage material because it is easy to store and decompose into CO_X-free hydrogen. A Ru-based catalyst exhibits good catalytic performance in ammonia decomposition, and enhancing the interaction between the Ru atoms and the support is an important way to further improve its catalytic activity. In this study, CeO₂ was prepared by calcination using a cerium-based metal–organic framework (MOF) as the precursor, and the number of oxygen vacancies on the surface of CeO₂ was regulated by hydrogen reduction. The XPS and Raman results showed that abundant oxygen vacancies were formed on the surface of these CeO₂, and their number increased with an increase in the reduction time. The Ru/CeO₂-4 h catalyst, using CeO₂ reduced for 4 h as the support, exhibited good catalytic activity in ammonia decomposition, reaching 98.9% ammonia conversion and 39.74 mmol g_cat⁻¹ min⁻¹ hydrogen yield under the condition of GHSV = 36,000 mL g_cat⁻¹ h⁻¹ at 500 °C. The XAFS results demonstrated that Ru was stably anchored with oxygen vacancies on the surface of CeO₂ via Ru-O-Ce bonds. Density functional theory calculations further showed that these bondings lower the reaction energy barrier for N-H bond cleavage, thereby significantly enhancing the catalytic activity. Full article

Mn(III)– and Co(III)–salen complexes (Mn-1 and Co-2) have been synthesized by a simple one-pot procedure through oxidation of Mn(II) and Co(II) precursors in air. X-ray structural analysis reveals that both complexes adopt similar coordination modes, including a typical square planar metal/salen coordination sphere, which is further occupied by two axial ligands, i.e., an acetate anion and a water molecule. Despite their structural similarity, they are not isomorphous given their distinct cell parameters. In the solid-state structures, both complexes exist as hydrogen-bonded dimers through hydrogen bonding interactions between the axially coordinating water molecules and outer O₄ cavity from another molecule of the complex. The reductive activity of both complexes has been explored. While the reaction of Mn-1 with potassium triethylborohydride was unsuccessful, leading to a complicated mixture, the use of Co-2 furnished the formation of a novel product (CoK-3) that was isolated as red crystals in reasonable yield. CoK-3 was characterized as a heterometallic dimer involving the coordination of a K⁺ ion within the O₄ cavity of a semi-hydrogenated salen/cobalt complex while the cobalt center has been reduced from Co(III) to Co(II). In addition, an attempt at reducing Co-2 with pinacolborane resulted in the isolation of crystals of Co-4, whose structure was determined as a simple square planar Co^II–salen complex. Finally, three complexes (Mn-1, Co-2 and CoK-3) have been investigated for their cytotoxic activities against two human breast cancer cell lines (MCF-7 and MDA-MB 468) and a normal breast epitheliel cell line (MCF-10A), with cisplatin used as a reference in order to discover potential drug candidates that may compete with cisplatin. The results reveal that Co-2 can be a promising drug candidate, specifically for the MCF-7 cancer cells, with minimal damage to healthy cells. Full article