Journal of Cluster Science最新文献

This study extracted copper from discarded printed circuit board (PCB) to improve the electrolyte variations on biosensing surfaces. A mixture of concentrated hydrochloric and nitric acids in volume ratios of 2:1, 1:2, and 1:1 was prepared for Sample A, Sample B, and Sample C, respectively, to examine copper recovery. Ultraviolet-visible spectrometry revealed an absorbance peak at 230 nm representing the formation of copper oxide nanoparticles (CuONPs). X-ray diffraction revealed the monoclinic structure of CuONPs with high crystallinity and an average size of 36–40 nm (n=3). Fourier transform infrared spectroscopy showed that Sample B had high CuONP purity. At the same time, a high-power microscope and 3D profiler revealed the 2D and 3D views of the electrode surface and gap distance with and without the attachment of CuONPs. Scanning electron microscopy revealed a 35 μm gap between the electrodes, which was reduced upon attaching CuONPs. Characterization analysis suggested that Samples B and C had the highest CuONP purity among the three samples examined; hence, these were selected for subsequent electrolyte scouting carried out on the electrode surface at pH 1 to 12 to determine the current variations of the sensor before and after using CuONPs from different samples with various levels (1, 10, and 100 mg/mL). A linear current curve with the least variation was obtained using 100 mg/mL of CuONPs from samples B and C. These results highlight the possibility of using CuONP attachment to alter the dielectric sensor surface to improve the sensitivity and performance of the device in terms of insensitivity towards electrolytes.

Silver(I) complexation with substituted (benzoimidazol-2-yl)methanamines Bz–CH₂–NH–R (Bz is 1-methylbenzimidazole, R is anisole (L¹) or 1-isopropylbenzimidazole (L²)) in the presence of boron cluster anions [B_nH_n]^2– (n = 10, 12) has been studied for the first time. The influence of substituent R in the benzimidazole derivative on the composition and structure of the resulting compounds has been determined. Coordination compounds [Ag(L¹)₂]_xAn (x = 1, An = {Ag[B₁₀H₁₀]}_m^m–; x = 2, An = [B₁₂H₁₂]^2–), featuring closo-borate anions in the outer coordination sphere and monodentately coordinated ligands L¹, have been synthesized and structurally characterized. Additionally binuclear complexes [Ag₂(L²)₂[µ-B_nH_n]] have been obtained, in which L² is coordinated bidentately, forming a seven-membered metallacycle, while anions [B_nH_n]^2– (n = 10, 12) act as bridging ligands. The structural features of the synthesized compounds have been analyzed, including the coordination mode of the organic ligands and the occurrence of positional and bond isomerism in compounds with coordinated boron cluster anions.

In this work, the g-C₃N₄/WO₃/ZnFe₂O₄ nanocomposite was synthesized using a combination of hydrothermal and ultrasonic techniques to design a Z-scheme system for the decolorization of the colored pollutant Rhodamine B (RhB). Initially, the synthesized catalyst was investigated using various characterization techniques, including X-ray diffraction, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy and Field emission scanning electron microscopy. The results confirmed the successful formation of crystalline g-C₃N₄/WO₃/ZnFe₂O₄. The XPS results clearly exhibited the presence of all constituent elements along with their respective oxidation states. Subsequently, g-C₃N₄/WO₃/ZnFe₂O₄ was examined for the first time for the photocatalytic decolorization of RhB dye under visible light illumination. To optimize the photodecolorization process, various parameters, including irradiation time, catalyst dosage, initial RhB dye concentration, and pH, were investigated. The results indicate that the Z-scheme system designed with g-C₃N₄/WO₃/ZnFe₂O₄ exhibits excellent capability in degrading RhB. Under optimal conditions of pH 7 and a catalyst dosage of 0.15 g/L, the system was able to degrade 98.7% of RhB (10 mg/L) within 75 min. Additionally, the results of scavenger experiments demonstrated that superoxide and hydroxyl radical species played a more significant role in the photocatalytic decolorization of RhB dye.

Phase change materials have gained significant attention in thermal energy storage technology, especially in solar thermal energy systems, because of their high energy storage capacity and broad temperature range of operation. This study develops and synthesise a novel Margaric acid—Stearic acid binary eutectic PCM which was investigated for its the thermophysical properties and chemical characteristics. Margaric acid- Stearic acid eutectic mixture had a weight composition of 64:36 and had a melting temperature at 66.03 °C with a latent heat of fusion 181.85 J/g. Prepared eutectic mixture was chemically stable and did not exhibit thermal degradation up to 200 °C. Carbonaceous nanoparticles were added at three different concentrations intending to triumph over the inherent low thermal conductivity of organic fatty acid components. Nano doping could achieve a highly favourable 9.7% increment in the latent heat of fusion measuring at 199.43 J/g and 130% increase in the thermal conductivity measuring at 0.352 W/mK, which would significantly contribute towards the thermal energy storage and retrieval characteristics of the PCM. The constituents and nanoparticles only developed a physical interaction between them and were chemically stable. The microstructural characteristics and surface morphology was studied through SEM analysis. The optical absorbance characteristics was drastically enhanced by nano doping. The synthesized eutectic mixtures demonstrated thermal stability at temperatures significantly higher than their melting point and maintained their thermal properties and chemical stability even after 500 accelerated thermal cycles.

Silver nanoparticles synthesized through green methodologies can offer a low-cost, reproducible, and environmentally sustainable solution for enhancing seed germination and antibacterial activity. In the present study, varying sizes of silver nanoparticles (AgNPs) were synthesized using Neem (Azadirachta indica) leaves aqueous plant extract at varying pH (5.7, 7, 8.5 and 10) and a 2.5% AgNPs solution (26.54, 30.36, 27.88 and 26.73 ppm), respectively, were applied to low germinating tetraploid seeds of watermelon (Citrullus lanatus). The AgNPs were characterized by UV-Visible spectrophotometer resulted blue-shift of spectra as the pH increased, Dynamic light scattering confirmed decreased in size of nanoparticles as the pH increased, Transmission electron microscopy and Scanning electron microscopy analysis confirmed the spherical nature of AgNPs, and the presence of functional groups confirmed by Fourier transform infrared spectroscopy and Raman spectroscopy. However, average size of 51.75 nm at pH 8.5 gave 83% increase in germination, and 70% improvement with average size of 142.8 nm at pH 5.7 for tetraploid (KSP-13379) compared to untreated. A similar increase for diploid varieties (KSP-1127 and BSS-586) observed by 21.6% and 44.5% compared to untreated seeds. The highest germination percentages of 100%, 86.67% and 95.56% were obtained with AgNP (pH 8.5) nanoprimed compared to untreated 82.22%, 60% and 52.22% varieties of KSP-1127, BSS-586 and KSP-13379 respectively, at 21 days. The size of AgNPs synthesized at pH 8.5 is highly suitable for seed germination, germination index, vigor index and plant length of tetraploid and diploid varieties. Hence, the results indicate that AgNPs nanopriming at varying pH levels yields beneficial effects by producing nanoparticles of diverse sizes, thereby improving germination percentage, germination rate, and seedling length.

Boron is a chemically versatile element, capable of forming diverse chemical bonds (e.g., single, double, triple, 3-center 2-electron bonds, and more), which determines its chemical behavior as a pure substance and in compounds with other elements. Electron deficiency and tendency to form multicenter bonds give rise to the ubiquitous presence of clusters in structures of boron allotropes and of many boron compounds in bulk and molecular forms. Here we investigate a wide range of neutral boron clusters B_n (n = 2–60) using the first-principles evolutionary algorithm USPEX. We find clear preference for planar structures for n < 10, while there is a competition between planar, cage, bilayer, and tubular structures for n > 10. We identify magic clusters as those having positive second-order differences of the total energy (and additionally analyze their fragmentation energy and HOMO–LUMO gap). Most of the magic clusters have even n, the most notable exception being magnetic cluster B₃₉ with cuboctahedral shape. Investigating the concept of aromaticity of inorganic compounds, we applied such approaches as nuclear independent chemical shift (NICS) and adaptive natural density partitioning (AdNDP) to a number of boron clusters and found that two clusters, B₁₀ and B₁₃, are aromatic (the former being magic).

Natural glauconite (GN) underwent facile exfoliation and scrolling modifications, resulting in two advanced structural derivatives with distinct morphologies: exfoliated glauconite nanosheets (Si-EXGN) and silicate nanorods (Si-GNRs). These derivatives exhibited enhanced physicochemical properties and were evaluated as both anticancer agents and delivery systems for cisplatin (CSPL). Compared to raw GN (119.3 mg/g), the modified derivatives exhibited significantly higher CSPL loading capacities: 309.4 mg/g for GNRs and 202.4 mg/g for EXGN. The loading behaviors were well-described by pseudo-first-order kinetics (R² > 0.94) and Langmuir isotherms (R² > 0.99). Advanced isotherm modeling highlighted the enriched interfaces of GNRs with a higher active site density (50.64 mg/g) compared to EXGN (38.4 mg/g) and GN (26.3 mg/g), allowing each GNR site to accommodate up to 7 CSPL molecules versus 5 for EXGN and 4 for GN. The loading process, governed by multimolecular physical interactions, was validated through loading energy values (<11 kJ/mol). The CSPL release profiles from EXGN and GNRs were continuous and prolonged, achieving 97.8% release after 200 hr and 100% release after 110 hr at physiological pH (7.4), respectively. Kinetic modeling revealed that the release process followed a non-Fickian transport mechanism, regulated primarily by diffusion and erosion. Specifically, release kinetics adhered to first-order (R² > 0.91–0.99), Hixson-Crowell (R² = 0.85–0.96), and Higuchi models (R² = 0.80–0.89). As standalone agents, EXGN (cell viability = 36.2%; IC50 = 230 µg/mL) and GNRs (cell viability = 22.4%; IC50 = 189.7 µg/mL) exhibited notable anticancer effects against human cervical cancer (HeLa) cells. Furthermore, when utilized as carriers for CSPL, their therapeutic efficacy was significantly enhanced. The CSPL-loaded EXGN system reduced cell viability to 2.3% (IC50 = 5.4 µg/mL), while the CSPL-loaded GNRs achieved superior cytotoxicity with a cell viability of 0.87% (IC50 = 1.6 µg/mL). The study underscores the potential of Si-EXGN and Si-GNRs as highly efficient drug delivery systems and anticancer agents. However, further in-depth in vivo evaluations are recommended to confirm the safety and biocompatibility of these materials.

The fluorescence mechanisms of the fluorescent probes 2-(4-morpholinophenyl)-4-oxo-4 H-chromen-3-yl acrylate (LFA) for the detection of cysteine in lysosomes and 3-hydroxy-2-(4-morpholinophenyl)-4 H-chromen-4-one (LF) were investigated based on density functional theory (DFT) and time-dependent density functional theory (TDDFT). The enhancement of hydrogen bonding in the excited state of LF molecule was proved by the geometric parameters, interaction region indicator (IRI) equivalence surface and IR vibrational spectra. Due to the low barrier of the potential energy curve (PEC), the LF occurs the excited state intramolecular proton transfer (ESIPT). In addition, both LFA and LF have the characteristics of intramolecular charge transfer (ICT), as determined by the Frontier molecular orbitals (FMOs), hole electron maps and D-index analyses. Due to non-radiation transition, the LFA is quenching by the calculation of reorganization energy and transition dipole moment.

Nickel oxide (NiO) nanoparticles were prepared using the co-precipitation method, and then activated carbon (AC) powder was blended with NiO with percentages of 25, 50, and 75%. X-ray diffraction patterns confirmed the formation of both NiO and NiO/AC nanocomposite structures. The NiO and NiO/AC nanocomposite powders were also fully characterized by Brunauer–Emmett–Teller (BET), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), which evidenced that the nanoparticles were uniformly distributed with the AC. The NiO and NiO/AC nanocomposite powders were investigated as supercapacitor electrode materials in a 6 M KOH aqueous solution. NiO nanoparticles electrode delivered a specific capacitance of 235 F g^− 1 at a current density of 1 A g^− 1. In comparison, it was found that the AC50 (NiO/AC 50/50%) nanocomposite possessed the best electrochemical performance. It achieved specific capacitances of 325 F g^− 1 and 215 F g^− 1 at current densities of 1 and 5 A g^− 1, respectively. For practical application, the AC50 nanocomposite coin cell was assembled in 1 M TEABF₄/PC organic electrolyte with good electrochemical performance. It delivered a specific capacitance of 72 F g^− 1 at 1 mA g^− 1. It demonstrates remarkable electrochemical reversibility with 99.3% coulombic efficiency and 89.9% capacitance retention after 4000 cycles at the current density of 5 mA g^− 1. It also reveals a high specific energy of 62.5 Wh kg^− 1 and a specific power of 638 W kg^− 1 at a current density of 0.5 A g^− 1. Still, it exhibits a specific energy of 8.7 Wh kg^− 1 and a specific power of 6944 W kg^− 1 at a current density of 5 A g^− 1, estimating this material’s potential for use in supercapacitors.

Metatitanic acid particles are the clusters formed through aggregation and agglomeration of nano-sized anatase crystallites in the hydrolysis process of titanyl sulphate. The uniformity of particle sizes and consistence of compositions of metatitanic acid particles precipitated from hydrolysis of titanyl sulphate solution are important for the morphology of TiO₂ particles and their optical properties. There have been numerous research efforts on the hydrolysis process, but there is little research on the detailed evaluation of the formation and growth of metatitanic acid particles at each important point in the hydrolysis process of titanyl sulphate. Herein, we report a study of the particle sizes and size distributions of metatitanic acid particles in the key points of the hydrolysis process, using the Light Scattering Particle Size Analyzer and Scanning Electron Microscopy. We found that at the point when initial particles appeared from solution, metatitanic acid exist predominately as primary particles and the primary particles continue to grow in size from gray point and are largely free of agglomeration. After secondary boiling, the primary particles disappear and the secondary particles become predominate. This investigation has implications on the optimal control of the uniformity of particle sizes and quality of metatitanic acid particles.