Journal of Cluster Science最新文献

The present investigation successfully synthesized a novel tantalum-based CuTaS₃/AgTaS₃ heterostructure using D-penicillamine as a sulfur source and investigated its hydrogen evolution capability using both photocatalytic and electrocatalytic methods. The structural and morphological features were examined using XRD, Raman, FT-IR, TEM and SEM with EDS analysis, respectively. The UV-DRS results ascertain the visible-light response and bandgap of the synthesized materials. Combining AgTaS₃ with CuTaS₃ reduced the recombination rate, as revealed by the photocurrent measurements of the materials. The photocatalytic hydrogen production for the as-synthesized materials was investigated by consuming Na₂S + Na₂SO₃ as a sacrificial reagent. The CuTaS₃ with 5% of the best AgTaS₃ loading gives off the most H₂ evolution rate, 1430 µmol/g, after 5 h of being exposed to visible light. Furthermore, the electrocatalytic measurements were performed to assess the CuTaS₃/AgTaS₃ heterostructure for water-splitting hydrogen evolution reactions (HER). The results displayed that the enhanced HER reactivity with lower overpotentials and Tafel slope when heterostructure was formed. The higher double-layer capacitance (C_dl) value shows how many more active sites were formed after AgTaS₃ was combined with CuTaS₃. These results confirmed that the CuTaS₃/AgTaS₃ heterostructure generated H₂ effectively in both electrocatalytic and photocatalytic processes. The present work may bring innovative perceptions for the advancement of tantalum-based sulfide materials for green hydrogen production.

Mixed manganese/cerium oxide/hydroxyapatite composites are emerging as innovative materials with significant biomedical potential due to their antibacterial properties and biocompatibility. In this study, we synthesized mixed Mn/Ce oxide/HA composites using an ultrasonic-assisted sol-gel method, exploring their structural and functional characteristics through comprehensive analyses. Advanced characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-ray absorption spectroscopy (XAS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and nitrogen adsorption-desorption isotherms, revealed a composite with enhanced structural stability and porosity, optimized for antibacterial applications. XRD confirmed the integration of a fluorite-structured CeO₂ phase with hexagonal hydroxyapatite, while FT-IR and XANES analyses verified the presence of functional phosphate groups and mixed oxidation states (Ce³⁺/Ce⁴⁺, Mn²⁺/Mn³⁺/Mn⁴⁺), essential for antibacterial efficacy. SEM imaging displayed a unique flake-like morphology conducive to clustering, and EDS confirmed elemental composition. Notably, nitrogen sorption isotherms revealed a marked increase in surface area from 2 m²/g in pure HA to 11–16 m²/g in Mn/Ce oxide/HA, which may enhance bacterial interaction. Antibacterial assays demonstrated potent activity against Bacillus cereus (B. cereus), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), Escherichia coli (E. coli), and Salmonella typhi (S. typhi), linked to reactive oxygen species production and bacterial membrane disruption. This study highlights the robust structural and antibacterial features of Mn/Ce oxide/HA composites, advancing their suitability for biomedical applications, particularly in infection-resistant materials and bone grafts.

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Brain tumor is one of the deadliest types of cancer in the world. The basic necessity of brain tumor-targeted therapy is to reach and accumulate the required quantity in the tumor microenvironment while maintaining therapeutic efficacy. In this regard, the current study sought to create thymoquinone-encapsulated Eudragit L100-coated solid lipid nanoparticles (TQ-encapsulated E-SLNs) for the transport of loaded thymoquinone (TQ) to the brain. TQ-encapsulated E-SLNs were formulated using the oil-in-water microemulsion process, and their physicochemical properties were investigated. TQ encapsulation, loading capacity, and release behavior of E-SLNs were also investigated. In vivo biodistribution studies were conducted to assess TQ delivery and accumulation in several organs of female Wistar rats. The TQ-encapsulated E-SLNs were mostly spherical with a crystalline structure and extremely stable in the physiological buffer system. The highest content of TQ was released in pH 5.5 (78.215 ± 0.749%) at 22 h. The pharmacokinetics and biodistribution investigations revealed that released TQ from TQ-encapsulated E-SLNs after 48 h of administration accumulated 16.5 ± 1.5% in brain, 21.167 ± 1.041% in kidneys, 12.125 ± 0.781% in heart, 16.375 ± 1.317% in liver, 13.5 ± 1.8% in lungs, and 17.15 ± 1.5%. Later, molecular modeling studies revealed that TQ had a greater binding energy of -7.8 kcal/mol to EGFR. Thymoquinone binding energy was very close to the reference drug Temozolomide. Molecular dynamics simulation studies showed that the TQ-EGFR docked complex was extremely stable up to 100 ns. The findings showed that the fabricated TQ-encapsulated E-SLNs remained unchanging in circulation for up to five days. Therefore, E-SLNs fabrications show promise as a method for targeting brain malignancies across the BBB.

Scanning and transmission electron microscopy, powder X-ray diffraction and thermogravimetric analyses were used to study the dynamics of the sorption processes of ligand-free iron nanoparticles produced by highly efficient physical synthesis, namely, the molecular beam method. The structure, chemical and phase composition of Fe-NaCl condensates with different iron contents, crystallite dimensions (nanoparticles) and nanoparticle surface areas depending on the condensation temperature, which characterize the sorption capacity, primarily for moisture and oxygen, were studied. Finally, the gravimetric analysis method was used to investigate the kinetics of the relative change in the weight of porous Fe–NaCl condensates with different iron contents, depending on the condensation temperature. With increasing synthesis temperature, the nanoparticle size increases, and the specific surface area decreases. Therefore, by changing the size of the nanoparticles at the same volume, we can regulate the ratio of the nanoparticle surface to the nanoparticle volume, i.e., change the properties of the reaction surface and, in this way, the contribution of the excess surface energy to the total free energy of the system. The mass fraction of physically adsorbed and bound oxygen (moisture) correlates with the size (area, surface) of the nanoparticles.

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Sorption of oxygen and water by EB PVD ligand-free Fe@Fe₃O₄ nanoparticle in open matrix nanopore

This research presents the development of an innovative and eco-friendly composite material, Alginate-Coated Nano Iron Oxide-Graphene Oxide (Alg-Fe₃O₄@GO), designed to enhance the adsorption and photocatalytic degradation of cationic dyes in wastewater treatment. The composite combines the biocompatibility of alginate with the high surface area and photocatalytic properties of graphene oxide and nano iron oxide. A comprehensive evaluation of the Alg-Fe₃O₄@GO composite was conducted to assess its efficiency in removing Methylene Blue (MB) and Malachite Green (MG) from aqueous solutions. Characterization techniques, including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area analysis, and Thermogravimetric Analysis (TGA), confirmed its structural and functional properties. BET analysis indicated a significant surface area of 317.8 m²/g, suggesting substantial adsorption capacity. Adsorption experiments revealed a maximum capacity of 163.8 mg/g for MB, achieving a removal efficiency of 98.5%, and 107.5 mg/g for MG, with a removal efficiency of 90.8% after 240 min of contact time at an initial dye concentration of 100 mg/L for both dyes. Kinetic studies indicated that the adsorption followed the Pseudo-Second Order model (R² > 0.99 for both dyes), while equilibrium data fitted well with the Langmuir Isotherm Model, indicating monolayer adsorption. Thermodynamic analysis indicated that the adsorption process was endothermic, with enthalpy changes of ΔH° = +25.33 kJ/mol for MB and ΔH° = +20.83 kJ/mol for MG, alongside a spontaneous nature (ΔG° < 0). Photocatalytic tests under visible light showed dye degradation efficiencies of 85.0% for MB and 78.0% for MG within 120 min. The composite retained over 85% of its initial adsorption capacity after six regeneration cycles, underscoring its potential as a sustainable, high-performance material for wastewater treatment.

This study presents the novel development of heterostructure Fe₂O₃/BiVO₄ composites as efficient photocatalysts, specifically utilizing a 20-W UV-A lamp for low-energy, sustainable environmental remediation. The combination of Fe₂O₃ and BiVO₄ produces a composite with enhanced photocatalytic performance through synergistic interactions. The composites were synthesized through a hydrothermal process with varied Fe ratios, followed by calcination. Characterization techniques, including XRD, SEM, TEM, EDS, XPS, BET surface area analysis, UV-DRS, and PL, confirmed composite formation, optimal particle dispersion, and improved surface properties. UV-DRS showed visible light absorption (bandgap energies: 2.27–2.47 eV), and PL confirmed effective charge separation critical for photocatalysis. Under low-power UV-A irradiation, the composite achieved 98.74% degradation of methylene blue (MB) with a rate constant of 0.0270 min⁻¹, outperforming the individual Fe₂O₃ and BiVO₄ components. This work demonstrates the potential of heterostructure Fe₂O₃/BiVO₄ composites as eco-friendly, high-efficiency photocatalysts, offering a sustainable approach to environmental cleanup and advancing the application of low-energy photocatalytic systems in broader photocatalysis fields.

Polyoxometalates (POMs), a class of discrete metal-oxo clusters with diverse structures and properties, are used in energy, biology, catalysis, and sensing applications, as well as in material design and assembly. POM-based catalysts, which have adjustable compositions and abundant available structures, have useful characteristics, such as having a tunable acid-base, being redox stable, being recyclable, and having sustainable features. Nerve agents are a type of chemical warfare agent (CWA) which are easily available and pose threats to human security and the environment. POM-based catalysts can be used in the catalytic decontamination of nerve agents. This review provides a basic introduction to the catalytic decontamination of nerve agents by POM-based catalysts that are classified according to the methods used for the catalytic degradation of the nerve agents. This review summarizes the breakthroughs in the development of POM-based catalysts for the degradation of CWAs over the past decade and discusses the benefits, challenges, and opportunities in the use of POM-based catalysts for the catalytic decontamination of nerve agents.

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This review summarizes research progresses of polyoxometalate-based catalysts on catalytic decontamination of nerve agents in the past decade with an emphasis on the design, structures and their catalyst performances

All-inorganic perovskite quantum dots have sparked a research boom due to their excellent optical properties, however, their own strong ionicity and lead toxicity have hindered further development in the field of sensing. In this study, we have solved the toxicity problem of lead-based perovskite quantum dots by replacing lead with green metal bismuth. Meanwhile, due to the ligand-passivation effect of oleylamine and oleic acid, we successfully synthesized highly stable bismuth-based perovskite quantum dots(Cs₃Bi₂Br₉ PQDs)in ethanol, and constructed the environment-friendly fluorescence sensor for the quantitative detection of oxytetracycline (OTC) for the first time. The results demonstrated that the fluorescence quenching degree of Cs₃Bi₂Br₉ PQDs showed a good linear relationship with the concentration of OTC within the range of 2.0 ~ 18 µM, and the detection limit was 0.432 µM. By studying fluorescence lifetime, absorption spectroscopy, and evaluation of internal filtration parameters, it was proved that the sensing mechanism was caused by the inner filter effect owing to the overlapping of fluorescence emission spectrum of Cs₃Bi₂Br₉ PQDs and UV absorption spectrum of OTC. Moreover, Cs₃Bi₂Br₉ PQDs fluorescent sensor had good selectivity and anti-interference ability. It is believed that this work will open up a new way for lead-free perovskite quantum dots fluorescence sensor in the field of analytical detection.

Ni_0.6−xZn_xMn_0.4Fe₂O₄ (x = 0.0,0.2,0.4,0.6) were prepared by the combustion method using hexamine as the fuel. Zinc replacement in place of Ni and its effect on various structural, electric, magnetic, and dielectric properties was studied using several instrumental techniques. X-ray diffraction revealed a monophasic cubic spinel structure for the samples. Scherrer’s formula determined that the crystallite size (D) was in the nano range from 8 to 15 nm. The lattice constant values showed an increment with zinc content while porosity was seen to drop. The scanning electron microscopy images showcased agglomerated particles due to magnetic interaction between them and were found to have spherical morphology. TEM provided the average particle size obtained from the histogram, while the SAED pattern revealed the semicrystalline nature of the samples. Infrared spectra showed two metal-oxygen peaks peculiar to spinel ferrite in the range of ~ 400–600 cm^− 1. Confirmation of the spinel phase was made using room temperature Raman analysis, and the change in Raman peaks was observed with an increase in zinc content. XPS studies revealed Ni^+ 2, Mn^+ 2, Zn^+ 2, and Fe^+ 3 to be in their respective valence states. A resistivity study was conducted from RT- 500 °C, which showed a decrease in resistivity with an increase in temperature, a typical trend of semiconduction. Dielectric studies performed at RT showed the highest dielectric constant with the minimum dielectric loss for sample x = 0.2, while variable temperatures studied at different frequencies showed x = 0.6 with the highest dielectric constant. Saturation magnetization values increased up to x = 0.4, which Neel’s two sublattices model explained, and a further decrease in magnetization was explained by the Yafet- Kittle model. AC susceptibility revealed Curie temperature up to the point where the sample behaved as ferrimagnetic material. The main aim and objective were to explore the suitability of synthesized materials for their applications and to study zinc’s influence on various properties and antibacterial activity. The antibacterial activity of the samples was investigated as a potential candidate against highly resistant and infectious Staphylococcus aureus, and sample x = 0.2 showed the best results.

With the growing concern over the environmental and health risks posed by antibiotic contamination in water systems, this study evaluates the potential of iron and cobalt oxide nanocatalysts with varying molar ratios, synthesized using the co-precipitation method, for the efficient removal of antibiotics from aqueous solutions. The optimal nanocatalysts were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM), revealing high surface area and well-defined crystalline structures, enhancing catalytic activity. Kinetic analysis showed that Co_0.5Fe_0.5Fe₂O₄ exhibited the best performance, with a Michaelis–Menten constant (K_m) of 0.0366 mM and maximum reaction velocity (V_max) of 1.10 × 10⁻⁴ µM.min⁻¹. The reaction rate constants, k₁ = 6.12 × 10³ M⁻¹ S⁻¹ and k₃ = 3.64 × 10² M⁻¹ S⁻¹) and turnover number (kcat = 5.213 × 10⁻¹ S⁻¹) confirmed its superior catalytic properties. Antibiotic removal was further evaluated through batch adsorption experiments, with adsorption kinetics and isotherms studied to determine optimal conditions for antibiotic removal. The Co_0.5Fe_0.5Fe₂O₄ nanocatalyst exhibited superior peroxidase-like activity compared to the other nanocatalysts when tested with the common chromogenic substrate 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) diammonium salt. Based on this enzymatic activity, a colorimetric sensing platform was designed for H₂O₂ detection. Additionally, the Co_0.5Fe_0.5Fe₂O₄ nanocatalyst exhibited excellent adsorption capacity for various antibiotics, including ciprofloxacin, azithromycin, levofloxacin, moxifloxacin, amoxicillin, and metronidazole, with 100% removal efficiency under optimal conditions. This study highlights the potential of enzyme-mimicking nanostructures as efficient adsorbents for the removal of antibiotics from aqueous solutions, addressing significant environmental challenges posed by antibiotic contamination.