Journal of Cluster Science最新文献

This study presents a series of high-sensitivity sensors based on BiVO₄-La₂O₃ (Bismuth vanadate-Lanthanum oxide). nanocomposite, synthesized using a simple hydrothermal process for the detection of NO₂ gas at room temperature. As-prepared samples were characterized using X-ray diffraction (XRD), ultraviolet visible spectroscopy (UV-vis), and Fourier transform infrared spectroscopy (FTIR). BiVO₄-La₂O₃ achieved excellent NO₂ gas sensing performance, including high sensor responsivity (Rg/Ra) of 13.5 at concentrations ranging from 0.1 ppm to 10 ppm, as well as fast response (T₉₀ = 76 s) and recovery (T_r90 = 66 s) times at 0.1 ppm. These results demonstrate the potential of BiVO₄–La₂O₃ nanocomposites for reliable ppb-level NO₂ detection at room temperature.

Cystic echinococcosis, caused by Echinococcus granulosus, is a global health concern requiring novel treatments. This study developed polyvinyl alcohol (PVA) and chitosan (CS) nanofibers loaded with Allium sativum (AS) extract, which contains allicin, a compound with antiparasitic properties. Electrospinning, a technique using high voltage to form nanofibers from a polymer solution, produced uniform, bead-free PVA/CS/AS nanofibers with an average diameter of 430.0 ± 1.4 nm. Characterization via GC-MS, SEM, FT-IR, and water contact angle measurements confirmed AS incorporation and revealed higher wettability than PVA/CS nanofibers, potentially enhancing biological interactions. In vitro, a 25 mg/ml AS extract concentration, selected based on prior antiparasitic studies, was tested against E. granulosus protoscoleces at 30, 60, and 90 min. PVA/CS/AS nanofibers markedly reduced viability, achieving mortality rates of 78.7%, 92.59%, and 98.38%, respectively, compared to 62.6%, 78.7%, and 93.7% for AS alone. These results suggest that PVA/CS/AS nanofibers enhance AS extract delivery and efficacy against the viability of E. granulosus protoscoleces. Further in vivo research is needed to evaluate their therapeutic potential.

This study investigates the synthesis and photocatalytic performance of CeO₂/porphyrin nanocomposites, created by self-assembling porphyrin monomers onto CeO₂ nanoparticles, which were green-synthesized using Cleistocalyx operculatus leaf extract. The resulting CeO₂/porphyrin composite showed enhanced photocatalytic efficiency for degrading organic pollutants, such as methylene blue and rhodamine B, compared to individual CeO₂ nanoparticles and free porphyrin aggregates. CeO₂ nanoparticles were characterized by SEM, XRD, FTIR, EDX, and UV-Vis, confirming successful synthesis and their crystalline integrity. The porphyrin TCPP (Tetrakis(4-carboxyphenyl)porphyrin) was integrated via a reprecipitation method, and SEM and XRD analysis verified the uniform incorporation of TCPP onto CeO₂ nanoparticles, preserving the nanofiber morphology and a crystalline structure with an average size of 9 nm. The CeO₂/TCPP composite exhibited extended visible light absorption, as shown in UV-Vis diffuse reflectance spectra, indicating its potential for photocatalytic applications under visible light. Photocatalytic tests under simulated sunlight demonstrated a significant improvement in performance, with a 95.9% degradation of Rhodamine B after 120 minutes, particularly at a CeO₂:TCPP ratio of 10:1. This research highlights the effective synergy between CeO₂ and porphyrin materials, providing a novel approach for developing efficient, green-synthesized nanocomposites for environmental remediation under visible light, marking a significant contribution to photocatalytic technology.

This study aimed to design, fabricate, and characterize a novel nanocomposite scaffoldAQ based on alginate-xanthan, incorporating copper-doped bioactive glass nanoparticles, for potential applications in regenerative endodontics. Bioactive glass nanoparticles with varying copper concentrations (0(B0), 0.5(B0.5), 2.5(B2.5), and 5(B5) wt%) were synthesized using the sol-gel method. Subsequently, scaffolds (pristine alginate-xanthan (A-X) and those incorporating the various copper-doped bioactive glasses (A-XB0, A-XB0.5, A-XB2.5 and A-XB5)) were fabricated via 3D printing. The synthesized nanoparticles and scaffolds were characterized by Fourier Transform Infrared Spectroscopy (FTIR) for chemical bonds and functional groups; Energy-Dispersive X-ray Spectroscopy (EDS) for elemental composition; X-ray Diffraction (XRD) for crystalline/amorphous structure; Scanning Electron Microscopy (SEM) for morphological and surface analysis; and Dynamic Light Scattering (DLS) for particle size and distribution. Subsequently, their hemocompatibility, antioxidant properties, and biodegradation were evaluated to assess their biological capabilities. The A-XB2.5 scaffold exhibited desirable surface roughness (by creating nano/micro fibers) and a well-distributed nanoparticle structure. The FTIR and EDS analyses confirmed the successful incorporation of copper into the bioactive glass structure, while XRD revealed an amorphous nature of the nanoparticles. Hemocompatibility tests indicated that the A-XB2.5 scaffold exhibited the lowest hemolysis rate, suggesting excellent blood compatibility. Antioxidant assays revealed that the A-XB2.5 scaffold exhibited the highest free radical scavenging activity, which decreased at higher copper concentrations due to potential oxidative stress. Degradation studies showed that the A-XB5 scaffold had the lowest degradation rate, indicating enhanced structural stability. This study successfully synthesized and characterized a novel alginate-xanthan nanocomposite scaffold containing copper-doped bioactive glass and investigated how copper concentration impacts its properties. We found that the A-XB2.5 scaffolds provided the most favorable characteristics, including uniform nanoparticle distribution, desirable surface roughness (by creating nano/micro fibers), enhanced antioxidant properties, and excellent hemocompatibility. In contrast, A-XB5 scaffolds led to significant nanoparticle aggregation, reduced antioxidant properties, and increased hemolysis, indicating potential copper toxicity at elevated levels. These findings highlight the dual role of copper (beneficial at optimal doses and detrimental at higher concentrations) in biomaterial design.

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In this study, a facile, low cost and eco-friendly microwave-assisted hydrothermal method has been used and optimized for large-scale production of reduced graphene oxide (rGO) nanosheets. Different rGO samples have been prepared by the modified Hummers method, followed by microwave-assisted reduction at different MW temperatures of 190, 200, 210, 250 °C for 3, 10, 15, 17, 20 and 25 min irradiation time. The morphological, crystallographic and structural analyses of the different produced rGO samples have been investigated using surface area S_BET, TEM and XRD techniques. The HRTEM images confirm the formation of rGO nanosheets with few lots of wrinkles. The XRD confirmed the complete transformation of GO into rGO after only 15 min of microwave irradiation. The surface area analyses showed a remarkable increase in the S_BET and the total pore volume by reduction of GO into rGO (from 0.7 to 26.3 m².g^-1 and from 0.012 to 0.17 cm².g^-1). The produced rGO samples have been tested for dual adsorptive removal of Fe³⁺ metal ions and methylene blue (MB) dye pollutant. A high adsorptive removal efficiency of 95.5% and 99.5% for Fe³⁺ and MB has been achieved using rGO-17 min, 200 °C optimum sample. The Langmuir isotherm model highlighted adsorption capacities (qm values of 126.1 mg.g^-1 for Fe³⁺ and 27.24 mg.g^-1 for MB), confirming the effectiveness of the optimized rGO sample. Additionally, Form the practical point of view and for the first time, the optimized rGO sample has been tested on real wastewater sample. The removal efficiency of both Fe³⁺ and dye content was approximately 57% after 8 h and 49% after only 2 hours, respectively. This demonstrates an optimized low-cost and sustainable method for wastewater remediation.

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Gas-phase B_n⁺ monocations exhibit strong hydrophilicity due to the prototypical electron-deficiency of boron. Joint chemisorption experiment and first-principles theory investigations performed herein indicate that the experimentally known planar magic-number C_2v B₁₃⁺ can react with H₂O at room temperature to form a series of quasi-planar aromatic boron water complexes C₁ B₁₃(H₂O)⁺ (1), C₂ B₁₃(H₂O)₂⁺ (2), and C₁ B₁₂H(H₂O)⁺ (3) analogous to benzene C₆H₆. Extensive theoretical calculations and analyses unveil their chemisorption pathways, bonding patterns, and more importantly, the effective in-phase LP(H₂O:)→LV(B) orbital overlaps between the more electronegative O atom in H₂O as lone-pair (LP) σ-donor and periphery electron-deficient B atoms in B₁₃⁺ (B₃@B₁₀⁺) and B₁₂H⁺ (B₃@B₉H⁺) with lone vacant (LV) orbitals as LP σ-acceptors, evidencing the existence of the newly proposed boron bonds in chemistry. A LP(H₂O:)→LV(B) boron bond in these boron water complexes possesses about 15 ~ 20% of the dissociation energy of a typical O–B covalent bond. Boron bonds are expected to exist in a wide range of boron-based complex systems with typical molecular ligands like H₂O, CO, and NH₃ as effective σ-donors.

Graphical Abstract

Joint chemisorption experiment and first-principles theory investigations indicate that B₁₃⁺ monocation can react with H₂O to form a series of quasi-planar aromatic boron water complexes C₁ B₁₃(H₂O)⁺, C₂ B₁₃(H₂O)₂⁺, and C₁ B₁₂H(H₂O)⁺ analogous to benzene, evidencing the existence of boron bonds in chemistry.

Nanocrystalline NaLi₂PO₄:Sm³⁺ (0.1 mol %) powder phosphor material was synthesized via solid-state reaction method in air atmosphere. The material was characterized by XRD, FESEM, EDS, FTIR, Raman and UV-Visible spectroscopy. Furthermore, the thermoluminescence (TL) dosimetric response of the nanocrystalline powder samples was also examined. XRD analysis revealed the highly crystalline orthorhombic structure of the primary phase with an average crystallite size of 31 nm, alongside the presence of an additional secondary phase indicative of a distinct material. FESEM revealed significant agglomeration, containing non-uniform, irregular, self-oriented clusters having average particle size of 0.37 μm. EDS verified the substantial weight percentages of Samarium in the NaLi₂PO₄:Sm³⁺ composition. FTIR spectroscopy provided prominent absorption bands at 1060 and 1019 cm⁻¹ corresponding to the stretching vibrations of the (PO₄)³⁻ group. Raman spectroscopy further corroborated the presence of distinct vibrational modes of the (PO₄)³⁻ group, associated with the nanoparticle surface. UV-Visible spectroscopy revealed characteristic charge transfer transition of PO and multiple sharp f–f transitions, including a prominent absorption band at 401 nm attributed to the ⁶H_5/2 →⁶P_3/2 transition of Sm³⁺ ions. The influence of various annealing conditions on the TL response of NaLi₂PO₄:Sm³⁺ was investigated. Samples were irradiated at various doses from ⁶⁰Co γ-source. Phosphor showed a prominent TL peak at 207 °C. TL glow curve of this phosphor, irradiated by ⁶⁰Co γ-rays at 40 Gy dose, measured at heating rate of 10 K/s has 8 deconvoluted glow peaks leading to highly dense trap at 478 K. Moreover, material showed the linear dose response against gamma radiations ranging 0–40 Gy. Based on these results, NaLi₂PO₄:Sm³⁺ (0.1 mol %) is a promising material and has good potential for TL dosimetry.

The utilization of metal-organic frameworks (MOFs) as luminescent sensors towards specific ions or molecular sensing has garnered significant attention, owing to their porous and easy-decorated feature. Herein, a Cu-based MOF (noted as SQ-1) has been synthesized using 5-amino-isophthalic acid as a bridging ligand. The SQ-1 was structurally characterized and demonstrated good thermal and water stability. Additionally, the benign luminescent properties of the ligands suggest its potential application as a luminescent sensor for detecting various anions. Notably, SQ-1 exhibited a remarkable selective and sensitive sensing ability towards Cr₂O₇²⁻ compared to other anions via luminescence quenching response, with the K_sv of 3.98 × 10⁴ M⁻¹ and detection limit of 4.32 µM. The quenching mechanism has been explored. Furthermore, this Cu-based MOF shows promise as a reusable luminescent sensor, maintaining functionality over three consecutive sensing cycles.

This study aims to prepare a chitosan-based nanocomposite of crosslinked chitosan-tartaric acid/copper oxide nanoparticles (CTS-TA/CuO) for safranin T (SFT) dye adsorption. The CTS-TA/CuO nanocomposite was extensively characterized using Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), and X-ray diffraction (XRD). The BET analysis revealed a mean pore diameter of 12.14 nm and surface area of 7.49 m²/g. The adsorption process was optimized using the Box–Behnken design (BBD), considering key parameters such as CTS-TA/CuO dosage (0.02–0.08 g), solution pH (4–10), and contact time (10–50 min). Kinetic modeling demonstrated that the adsorption followed the pseudo-first-order model, while equilibrium data best fit the Freundlich isotherm model. The maximum adsorption capacity of the CTS-TA/CuO nanocomposite for SFT was computed to be 210.48 mg/g. The adsorption mechanism was attributed to multiple interactions, including electrostatic attractions, n-π interactions, and hydrogen bonding. Overall, the findings of this study highlight the promising capability of the CTS-TA/CuO nanocomposite as an efficient and reliable adsorbent for the removal of SFT dye from polluted water, signifying its prospective utilization in wastewater treatment techniques.

The family of chalcogenide rhenium clusters is well represented in the literature by a series of compounds with different nuclearities, including heterometallic complexes. Here we report the synthesis and detailed characterization of new cyanide clusters [{Re₈Se₈(µ-O)₃}(CN)₁₈]^8– and [{Re₁₂S₁₄}(CN)₂₇]^9–. Both compounds were obtained by reactions of ReI₃, RuCl₃ and elemental selenium or sulfur with KCN at elevated temperatures, reflecting attempts to prepare heterometallic complexes with noble metals. The first cluster can be visualized as two fragments [{Re₄Se₄}(CN)₉]^– linked by three µ-O^2– bridging ligands. The second one can be represented as three tetrahedral [{Re₄S₄}(CN)₉]^– fragments linked by two µ₃-bridged sulfide ligands. Two of three {Re₄S₄} cores are additionally linked by direct Re–Re bond.