Journal of Sol-Gel Science and Technology最新文献

Brownmillerite Ca₂Fe₂O₅ nanoparticles (NPs) were synthesized via a modified Pechini sol-gel method, yielding a crystallite size of 41 ± 7 nm. X-ray diffraction (XRD) confirmed the orthorhombic phase with lattice parameters (a = 5.559 Å, b = 14.771 Å, c = 5.429 Å), consistent with JCPDS data. Fourier transform infrared (FTIR) spectroscopy identified Fe–O–Fe and Ca–O bonds, while energy-dispersive X-ray spectroscopy (EDS) verified the desired stoichiometric Ca:Fe:O ratios. Scanning electron microscopy (SEM) revealed an irregular, layered morphology with a high surface area, suitable for catalytic applications. UV-Vis spectroscopy showed an absorption peak at 361 nm, a direct bandgap of 1.89 eV, and an Urbach energy of 0.182 eV, indicating strong optoelectronic potential. The NPs exhibited excellent photocatalytic performance, degrading 94% of Toluidine Blue (TB) dye in 120 min following first-order kinetics (k = 0.02366 min⁻¹). For industrial wastewater, they achieved 99% hydrocarbon (OIW) removal and 94% total suspended solids (TSS) removal in 60 min under sunlight, along with >99% heavy metal extraction (e.g., Se, Mo, Sb, As). Driven by reactive oxygen species (ROS), including hydroxyl and superoxide radicals, Ca₂Fe₂O₅ NPs provide a sustainable and efficient solution for environmental remediation, particularly for dye-contaminated and petroleum wastewater treatment.

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The structural, optoelectronic, elastic, thermodynamic, and mechanical properties of Sr₂XH₇ (X = B, Ga, and Al) complex hydrides are investigated in this study using HSE06 functional computations in density functional theory (DFT). The measured direct band gaps for Sr₂BH₇ (1.044 eV), Sr₂GaH₇ (2.295 eV) and the indirect band gap for Sr₂AlH₇ (3.273 eV) hydrides show that they are semiconductors and suitable for hydrogen storage applications. Hydrogen atoms have strong localized regions with values closer to 1.0, indicating their anionic character (H^-) due to charge transfer from strontium. From measured results, all hydrides possess high absorption coefficient (10⁵cm^–1), dielectric function (7–9), refractive index (2.5-3.3) and peaks appear in the visible and near-UV regions. The mechanical characteristics of all hydrides exhibit anisotropic behavior in the XY, YZ and XZ directions, and their mechanical parameter (B/G > 1.75) confirms their ductile nature and potential for optoelectronic applications. The thermodynamic properties are investigated using the Density Functional Perturbation Theory (DFPT) technique. The zero point energies for Sr₂XH₇ (X = B, Ga and Al) hydrides are 6.1101 eV, 5.0702 eV and 5.2436 eV, respectively. Variations in these zero-point energies reveal strong bond strengths and atomic interactions. The alkaline earth metal poly-hydride family members Sr₂XH₇ (X = B, Ga and Al) have shown good GHSC values for Sr₂BH₇ (3.66%), Sr₂GaH₇ (2.80%) and Sr₂AlH₇ (3.37%), indicating their potential for next-generation hydrogen storage applications.

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Template-driven sol-gel microencapsulation of rosemary (Rosmarinus officinalis) essential oil within submicrometric SiO₂ core-shell microcapsules affords a new solid biopesticide dubbed herein “SiliRosm” that can be readily formulated in water, enhancing the stability and bioactivity of the essential oil. Comparing two sol-gel microencapsulation routes to optimize encapsulation efficiency and protection of the bioactive compounds, this study shows that the sol-gel microencapsulation of the essential oil facilitates the sustained release of its molecular components via the Baker–Lonsdale release kinetic model. First results showing high biocidal activity of SiliRosm formulated in water against highly polyphagous Spodoptera littoralis are promising toward the practical application of SiliRosm for crop protection.

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A novel solid biopesticide is prepared by the sol-gel microencapsulation of rosemary essential oil within spherical submicron SiO₂ core-shell microcapsules, which can be effectively formulated in water, showing promising insecticidal activity against polyphagous Spodoptera littoralis.

The current research explores the sustainable synthesis of AgNPs using 3,6-dihydroxyflavone, a bioactive flavonoid, and evaluates their multifunctional biological applications. The green-synthesized AgNPs were confirmed using UV-Vis spectroscopy, FTIR, XRD, SEM, TEM, EDS, DLS, and zeta potential analysis, confirming their crystalline nature, spherical morphology (22–28 nm), and moderate colloidal stability. The larvicidal potential of the AgNPs was assessed against An. stephensi, Cx. quinquefasciatus, and Ae. aegypti, with significant mortality observed at low concentrations, and LC₅₀ values ranging from 9.10 to 12.62 µg/mL. Histological examination revealed severe midgut damage in treated larvae, indicating disruption of digestive and structural integrity. The AgNPs also exhibited strong antioxidant activity in DPPH and ABTS assays. Significant antibacterial activity was observed against both Gram-positive and Gram-negative test pathogens, and the compounds potentially inhibit biofilm formation. Furthermore, cytotoxicity studies demonstrated dose-dependent anticancer activity against MCF-7 cells while screening for minimal toxicity in normal Vero cells. The ecotoxicological assessment using Artemia salina confirmed that the AgNPs were safe to non-target aquatic organisms at effective larvicidal doses. In parallel, molecular docking showed strong affinity for 1MV8 (-7.35 kcal/mol, Ki 4.12 µM), supporting its role in the antibacterial, anti-biofilm, and anticancer effects of the synthesized AgNPs. Overall, this study highlights the potential of 3,6-dihydroxyflavone-mediated AgNPs as a promising green nanoplatform for mosquito control and biomedical applications.

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Bioactive acrylic bone cements were created through the use of alendronate sodium functionalized poly(methyl methacrylate-co-acrylic acid) reinforced with calcium titanate or bioglass 45S5. Calcium titanate (CT) with an average diameter of 86 nm were synthesized via the sol-gel method. Bioglass was also synthesized by the sol-gel method without nitrate precursors and thermally treated at 380 (BG380) and 700 °C (BG700). BG380 showed crystalline rhenanite along with amorphous silicates, whereas BG700 contained fully crystalline combeite-like and needle-shaped silico-rhenanite (∼125 nm diameter). The copolymer includes spherical particles (∼398 nm) with a zeta potential of −51 mV. Alendronate resulted in calcium phosphate formation in crack zones after 7 days, while the incorporation of bioglasses exhibited lower bioactivity because of their partial crystallinity. Contrary, CT led to enhanced deposition at crack openings within 3 days and complete closure of cracks (<16µm) after 14 days. CT-containing composite showed a compressive strength of 24 MPa prior to soaking in SBF, which dropped to 19 MPa afterwards. In comparison to similar studies, this does not eliminate the possibility of diminished crack healing as a result of calcium phosphate deposition. These results demonstrate that alendronate-functionalized copolymer matrices reinforced with bioactive ceramics can support localized calcium phosphate formation, particularly in crack zones.

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Multilayer ZnTiO₃ thin films were synthesized on porous silicon (PS) substrates via a sol–gel spin-coating process, and their structural, optical, and photocatalytic properties were systematically investigated as a function of layer number. X-ray diffraction and Raman spectroscopy confirmed the formation of the hexagonal ZnTiO₃ phase, with enhanced crystallinity and reduced microstrain in thicker films. UV–Vis spectroscopy revealed a red shift of the absorption edge and a corresponding decrease in band gap energy from 3.81 to 3.06 eV, attributed to improved light harvesting and defect-mediated transitions. Morphological analyses indicated a transformation from discontinuous nanoparticles to compact nanocrystalline films with higher surface coverage on PS. These structural and optical improvements led to superior photocatalytic activity, achieving nearly complete methylene blue degradation under sunlight within 180 min. The results demonstrate that the synergistic coupling between ZnTiO₃ and porous silicon, combined with multilayer stacking, effectively enhances light absorption and charge separation, making this heterostructure a promising candidate for efficient solar-driven photocatalysis and environmental remediation.

Alkaline water electrolysis is a well-known process with a lot of promise for producing renewable energy, but it needs the right catalyst. The effectiveness of water electrolysis can be greatly improved with the right electrocatalyst. In order to catalyse the oxygen evolution reaction (OER), a multifunctional electrocatalyst made of aluminum sulfide–anchored graphene oxide (Al₂S₃/GO) was created using a hydrothermal process. The produced catalyst’s varied morphology and good crystallinity were validated by the physical characterization performed using XRD and SEM. In 1 M KOH, electrochemical performance was assessed using three-electrode system. The Al₂S₃/GO nanocomposite demonstrated a small Tafel slope of 35.4 mV dec⁻¹, a low overpotential of 218 mV at 10 mA cm⁻², and steady operating at elevated current densities up to 50 mA cm⁻². Additionally, after 5000 CV cycles, it maintained 92% of its starting current. The Al₂S₃/GO catalyst is stable, economical, and useful option for OER in alkaline solution, according to the overall results.

Despite the rising need for advanced antimicrobial materials to fight drug-resistant pathogens, conventional antibacterial treatments frequently have limited efficacy and stability issues. This study aims to overcome these issues by creating a unique Ag@ZIF-67 heterostructure that synergistically combines the structural benefits of metal-organic frameworks with the antimicrobial qualities of silver nanoparticles and provides longer-lasting and improved antibacterial activity. The heterostructure was created using a simple two-step procedure that involved in situ deposition of silver nanoparticles (Ag NPs) and controlled growth of zeolitic imidazolate framework-67 (ZIF-67). Scanning electron microscopy (SEM) confirmed the successful formation of the Ag@ZIF-67 heterostructure with well-dispersed Ag NPs (average size 10.96 nm) throughout the ZIF-67 matrix. The key innovation is the synergistic heterostructure design, which overcomes the rapid depletion and aggregation issues of traditional silver-based antimicrobials by allowing regulated silver release while producing reactive oxygen species through cobalt centers. Antimicrobial activity testing of Ag@ZIF-67 against common pathogens, including Staphylococcus aureus (S. aureus) and Klebsiella pneumoniae (K. pneumoniae), revealed superior inhibition compared to pristine ZIF-67 and Ag NPs, with minimum inhibitory concentrations (MICs) ranging from 3.9 to 7.8 μg/mL. This innovative Ag@ZIF-67 heterostructure represents a promising platform for preparing antimicrobial materials for healthcare and environmental applications.

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