Journal of Cluster Science最新文献

Vanadium pentoxide (V₂O₅) supported on multi-walled carbon nanotubes (MWCNT) was successfully synthesized to enhance its photocatalytic and antibacterial activities. The synergistic interaction between MWCNT and V₂O₅ led to a significant improvement in performance, particularly in the degradation of pollutants under visible light. The V₂O₅/MWCNT photocatalyst demonstrated remarkable efficacy, effectively removing 98% of Methylene Blue (MB) within 120 min. By assessing the photocatalyst’s performance over four successive recycling cycles, we evaluated its stability and sustainability, finding no significant losses in photoactivity. Characterization results, including XRD analysis, confirmed the material’s phase stability. Additionally, both V₂O₅ and the V₂O₅/MWCNT composite were evaluated for their antibacterial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by measuring the zone of inhibition (8±0.4 mm and 9±0.2 mm). The results indicate that the V₂O₅/MWCNT nanocomposite substantially enhances both photocatalytic and antibacterial properties. This multifunctional material represents a significant advancement in the field, offering a dual-action solution that combines effective pollutant degradation with robust antimicrobial properties, making it a promising candidate for applications in combating antimicrobial resistance and in water treatment.

An electrochemical sensor with excellent sensitivity has been developed for the continuous and selective identification of (DA) dopamine and (5-HT) serotonin via a platinum (pt) - doped reduced graphene oxide nanocomposite (Pt-doped rGO). The sensor utilizes the synergistic properties of its components: the increased surface area and electrical conductivity of rGO, the improved electron transfers due to platinum doping, and the structural benefits of the composite for efficient neurotransmitter detection. The Pt-doped rGO nanocomposite is produced by directly oxidizing graphite to generate graphene oxide (GO), subsequently reducing and functionalizing GO with platinum nanoparticles. Electrochemical characterization using differential pulse voltammetry (DPV) demonstrated clear separation of oxidation peaks for DA and 5-HT, allowing precise multiplexed detection. The sensor demonstrated superior electrocatalytic activity, selectivity, and no interference from ascorbic acid (AA), frequently found in electrochemical biosensing. The detection limits were 0.012 µM for both dopamine (DA) and serotonin (5-HT). The analysis of actual samples in human urine and serum validated the sensor’s practicality and reproducibility. The Pt-doped rGO composite effectively tackles significant issues in electrochemical biosensing, such as overlapping redox potentials and interference from intricate biological matrices, rendering it a promising platform for the highly sensitive and selective detection of neurotransmitters.

In this study, a composite of polyacrylonitrile and Sudan Black B was electrospun onto the surface of a pencil graphite electrode, resulting in the development of an innovative nanofiber electrochemical sensor. The proposed sensor exhibited remarkable catalytic performance when assessing dopamine concentrations through cyclic voltammetry and square wave voltammetry techniques. The morphology of the constructed sensor was characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. A linear calibration curve was established for dopamine detection in the range of 30 to 420 nanomolL^− 1, with a limit of detection determined to be 9.97 nanomolL^− 1. Furthermore, this method demonstrated satisfactory precision for the quantitative analysis of dopamine in human blood serum samples. All electrochemical evaluations of the fabricated sensors indicated consistent performance and reproducible activity. Consequently, this novel electrochemical probe is recommended for the interference-free measurement of dopamine in complex biological environments.

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Volatile organic compounds (VOCs) are hazardous contaminants released from industrial activities. They threaten human health and ecosystems, even at minimal doses. Nevertheless, the singular approach encounters issues, including excessive energy consumption, adverse environmental impact, and inadequate removal effectiveness. Currently, incorporating photocatalytic degradation of VOCs is regarded as a highly significant approach. Catalytic technology provides the benefits of cost-effectiveness and enhanced catalytic efficiency. The development of innovative catalysts is essential for the progress of catalytic technology approaches. Researchers have recently performed comprehensive studies and created innovative catalysts to treat multiple contaminants efficiently. The main aim of this article is to analyze the progress in catalyst research related to the synergistic catalysis of volatile organic compounds (VOCs). From the perspective of these constraints, novel photocatalysts are introduced and enhancing photocatalytic activity strategies such as introducing transition metal or non-metal ions, combining with other semiconductors, modifying the surface, altering the morphology, and employing various methods to achieve the degradation of simultaneously polar and nonpolar (VOCs) (specifically, toluene and formaldehyde, accordingly, it is the representative compounds) under visible light. This article presents a comprehensive analysis of the relevant literature, specifically focusing on three main areas: a concise description of surface design catalysts, various methodologies for constructing visible light catalysts, and the impact of environmental conditions. The review aims to examine the connections between the properties and applications of oriented materials to advance the creation of new substances. This review indicates substantial challenges in applying photocatalysts to eliminate VOCs selectively. Several approaches should be coupled to provide synergistic effects, which could result in significantly higher photocatalytic performance than individual approaches.

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A study on the simple synthesis of materials having a synergistic role as photocatalysts when exposed to sunlight irradiation and super-adsorbents in the dark is provided in the present article. NiO@g-C₃N₄ nanocomposite was prepared by mixing and ultrasonicating graphitic carbon nitride (g-C₃N₄) with NiO nanoparticles at a ratio of 1:1. XRD, XPS, BET, DR/UV-Vis spectroscopy, SEM, EDX, and zeta potential analysis were used for the samples’ analysis. XRD pattern of NiO@g-C₃N₄ conforms to the NiO pattern, with diminished peak strength at the main peak of g-C₃N₄, suggesting partial exfoliation of the lamellar g-C₃N₄ layers during the ultrasonication with NiO. In NiO@g-C₃N₄, the g-C₃N₄ sheets were irregularly covered with NiO nanoplatelets as confirmed by SEM images. Employing ciprofloxacin (CIP) as a pollutant model drug, the adsorption efficiency and various parameters influencing the adsorption process without light irradiation were investigated. The synergistic role of the NiO@g-C₃N₄ nanocomposite was studied, where it showed a CIP removal of 80% when exposed to sunlight irradiation versus 10% by adsorption in the dark after 60 min. The rate constant values indicated that NiO@g-C₃N₄ nanocomposite showed a faster photocatalytic degradation rate than bare NiO or bare g-C₃N₄. The band gap measurements and the band alignment of NiO and g-C₃N₄ suggest S-scheme heterojunction’s mechanism, which suppresses the e⁻-h⁺ recombination and increases the photocatalytic efficiency. NiO@g-C₃N₄ nanocomposite could be successfully recycled, where it showed removal of more than 50% of CIP after 4 photocatalysis runs. Moreover, the NiO@g-C₃N₄ was employed for CIP degradation in real water samples.

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Research interest in recent years have centred on advancements of functional nano-systems prepared from waste materials. The primary focus of this work is to develop a nanocatalyst and energy storage material from discarded aluminium foils, thus minimizing the negative impact of used aluminum foil on the soil. In this study, copper (I) oxide nanostructures were synthesized using waste aluminium foils by simple displacement method. The prepared material was applied to catalyse the reduction of 4-nitrophenol in the presence of NaBH₄, showing excellent activity towards the reduction within 14 min and conversion efficiency of 97% with appreciable reusability. The kinetic studies reveal the pseudo first order nature of the reaction with a rate constant of 0.7783 min⁻¹. Additionally, the inverse relation of rate constants with various concentration of 4-nitrophenol suggests the reduction process follows Langmuir–Hinshelwood mechanism. Moreover, the electrochemical performance of the electrode prepared using Cu₂O in 1 M KOH shows significant results, with a specific capacitance of 108 F g⁻¹ at 1 A g⁻¹ and cycling stability of 78% after 5000 continuous charge-discharge cycles. The Nyquist plot data of the synthesized material shows a lower resistance value of 2 Ω, indicating an enhanced electrochemical activity of the nanomaterial. This work proposes a sustainable and eco-friendly approach for utilizing waste materials to prepare multifunctional materials, which have extended applications in the fields of energy and the environment.

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Cobalt chromite nanoparticles (CoCr₂O₄ NPs) have emerged as an engrossing material class because of their wide range of uses spanning catalysis, magnetic recording, biomedical engineering, and environmental remediation. This review has addressed all the available literature and described the synthetic strategies, characteristics, and applications of imminent CoCr₂O₄ NPs. Various synthesis techniques, including sol-gel, hydrothermal, co-precipitation, sonochemical methods, and many more, are discussed, along with their influence on nanoparticle size, shape, and phase purity. Cobalt chromite finds diverse applications, serving as an industrial inorganic pigment, a substrate for film growth in dye processes, a solar absorber, a material exhibiting multiferroic properties, an electrode in solid oxide fuel cells (SOFCs), dye degradation, a gas sensor, catalyst support, and a catalyst for various reactions such as the catalytic combustion of dichloromethane, the complete oxidation of trichloroethylene (used to eliminate chlorinated organic pollutants), ortho-selective alkylation of phenol with methanol, complete oxidation of methane, and diesel soot removal, and the oxidation of 2-propanol. We are confident that this review will be a valuable resource for researchers interested in the production and diverse uses of CoCr₂O₄ nanoparticles.

Zinc oxide in nanometric dimensions, thanks to its optical properties, is an oxide of great interest for its potential use as a revealing agent for latent fingerprints. In this article we present the synthesis and characterization of ZnO nanoparticles obtained by two methods and it uses in revealing of latent fingerprints on non-porous surfaces. The nanoparticles synthetized present an atomic Zn:O ratio of 0.99 and 1.15 when precipitation and combustion in solution method were used, respectively. Both samples show a hexagonal arrangement (wurtzite) according to the X-ray diffraction and Raman spectra. Raman results show a shift at 439 cm⁻¹ corresponding to the E₂ (high) mode of the ZnO crystalline hexagonal wurtzite structure. Transmission electron microscopy images show that nanoparticles with smaller average diameters are obtained by chemical precipitation (17.2 ± 10.8 nm) than combustion in solution (73.4 ± 6.0 nm). Samples presented a narrow band gap of 3.69 and 3.59 eV, values higher than that reported for the bulk material (3.37 eV). The photoluminescence spectrum showed a characteristic ultraviolet emission peak around 387 nm and green emissions peaks from ZnO when excitation wavelength of 325 and 488 nm were experiment, respectively. Finally, ZnO nanoparticles were used to reveal latent fingerprints on non-porous surfaces using a 325 nm laser. Fingerprint development is better on black glass surface when using precipitated ZnO. However, Fingerprints are better observed in aluminum foil when ZnO obtained by combustion in solution is applied. The results show that it is possible to use ZnO nanoparticles obtained by both methods as latent fingerprint revealing agents.

Curcumin (CUR) exhibits significant efficacy against various cancers, including hepatocellular carcinoma (HCC). However, its limited oral bioavailability greatly restricts clinical applications. Lipid-based nanocarriers offer a promising strategy to enhance both the anticancer potential and oral bioavailability of lipophilic drugs. In this study, we have formulated a biotinylated CUR SNEDDS to target it more efficiently to tumor cells that overexpress biotin receptors, such as those found in HCC. This targeted delivery system aims to enhance the therapeutic efficacy of CUR while minimizing systemic toxicity, offering a more effective treatment strategy for HCC. For this purpose, the components of the formulation were determined based on their solubility as well as their capacity to emulsify. A ternary phase diagram was constructed for the components selected for the formulation to optimize the concentrations of the constituents. The developed SNEDDS were evaluated for thermodynamic stability, physicochemical properties, drug-excipient interactions, in vitro dissolution, and hepatoprotective activities. Histopathological analysis and gene expression data showed that the biotinylated CUR-SNEDDS exhibited therapeutic potential in an in vivo HCC model, reducing inflammation, fibrosis, and cancer nodules. The enhanced hepatoprotective activity of biotinylated SNEDDS can be attributed to the nanosized formulation, which solubilizes CUR, prolongs its half-life, and facilitates preferential accumulation at the biotin receptor, which is overexpressed in HCC. These findings highlight the potential of biotinylated SNEDDS as an effective therapeutic strategy for enhancing the efficacy and targeting of CUR in HCC treatment.

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This study investigates the seed-mediated growth of CoFe₂O₄ nanoparticles by continuously injecting Co(acac)₂ and Fe(acac)₃ precursors into triethylene glycol under thermal decomposition conditions. We focused on the effects of precursor injection speed and synthesis temperature. The optimal injection rate was ~ 40 mL/h, with higher rates causing excessive secondary nucleation, while lower rates led to nanoparticle aggregation due to faster ligand stripping than monomer adsorption. A novel growth mechanism was proposed, involving secondary nucleation and clusterization, where new seeds adsorb onto growing nanoparticles, aided by the absence of strong stabilizers. Growth kinetics were analyzed using the Arrhenius equation, yielding an activation energy of 40.8 kJ/mol. Temperature also played a critical role in crystallite growth and nucleation. As temperature increased, crystallite size grew from 3.4 ± 0.2 nm at 185 °C to 10.1 ± 0.5 nm at 265 °C, with minimal change in nanoparticle size measured by TEM. Magnetic measurements showed an increase in saturation magnetization, when the reaction temperature was increased. Same impact of temperature on coercive force was also observed. This increase was attributed to crystallite sizes exceeding the 7 nm threshold for CoFe₂O₄ and low lattice strain. According to hyperthermia measurements the heating ability improved with larger crystallite size and higher M_s, but excessive H_c​ for samples at 265 ^oC reduced efficiency. The findings enable precise control over nanoparticle growth and nucleation, allowing tailored synthesis of single- or polycrystalline CoFe₂O₄ with controlled magnetic properties. These advancements hold promise for a wide range of biomedical applications, including magnetic hyperthermia.