Journal of Sol-Gel Science and Technology最新文献

The increasing prevalence of antimicrobial resistance and the limitations of conventional wound dressings necessitate the development of sustainable and effective antimicrobial biomaterials. In this study, copper oxide nanoparticles (CuO NPs) were green synthesized using Turbinaria conoides extract and subsequently incorporated into starch/polyvinyl alcohol (PVA) electrospun nanofibrous scaffolds to enhance antimicrobial performance. The biosynthesized CuO NPs exhibited a characteristic surface plasmon resonance peak at 270–300 nm and a mean particle size of 68 nm with a zeta potential of −11.4 mV, indicating moderate colloidal stability. Structural and chemical analyses (FTIR and XRD) confirmed the formation of monoclinic CuO and phytochemical-mediated stabilization, while SEM revealed uniform nanoparticle distribution within nanofibers of 90–110 nm diameter. The CuO-loaded nanoscaffolds demonstrated significantly enhanced antimicrobial activity, with inhibition zones of 30 ± 0.2 mm (Escherichia coli), 27 ± 0.2 mm (Klebsiella pneumoniae), and 25 ± 0.3 mm (Staphylococcus aureus), outperforming both algal extract and CuO NPs alone. The improved efficacy is attributed to synergistic effects of nanoparticle incorporation and sustained release from the nanofibrous matrix. This study presents a novel integration of T. conoides-mediated CuO nanoparticles into biodegradable starch/PVA electrospun scaffolds, offering a sustainable and effective platform for antimicrobial wound dressing applications.

Titanium alloys such as Ti6Al4V are widely used in biomedical implants; however, their susceptibility to bacterial colonization remains a major challenge. In this work, magnesium oxide (MgO) nanoparticles were synthesized via a green route using Mangifera indica peel extract and subsequently deposited onto Ti6Al4V substrates by electrophoretic deposition (EPD) to explore their potential as antibacterial coatings. Following thermal analysis, the synthesized powders were calcined at 500 °C (HT500) and 700 °C (HT700). XRD and Rietveld refinement confirmed the formation of crystalline cubic MgO, with phase purities of 82.01 wt.% and 98.72 wt.% for HT500 and HT700, respectively. Crystallite size increased with calcination temperature, reaching approximately 62 nm for HT700 according to Rietveld refinement. SEM analysis revealed a transition from highly agglomerated particles to more defined polyhedral morphologies at higher calcination temperatures. The antibacterial activity of HT700 nanoparticles was evaluated against Escherichia coli and Staphylococcus aureus. A concentration-dependent reduction in bacterial viability was observed, with significant inhibition of E. coli from 3 mg/mL and S. aureus from 6 mg/mL onwards. The antibacterial effect was accompanied by an increase in culture medium pH, reaching values close to 10 at the highest nanoparticle concentrations. EPD successfully produced homogeneous MgO coatings on Ti6Al4V substrates, which showed a reduction in bacterial viability, particularly against S. aureus. Overall, these results demonstrate the feasibility of combining green-synthesized MgO nanoparticles with electrophoretic deposition to produce antibacterial Ti-based surface coatings, providing a proof-of-concept for the development of sustainable surface modifications for future biomedical applications.

This work systematically investigates the synergistic effect of 3-mercaptopropionic acid (MPA) coordination and solvent engineering on the structural, morphological, vibrational, and electrical properties of sol-gel-derived Cu₂ZnSn(S,Se)₄ (CZTSSe) thin films. CZTSSe absorbers were fabricated using precursor solutions with and without MPA under different solvent environments (MOE: DMF solvent ratios of 50:50 and 25:75), followed by selenization. GIXRD and Raman analyses confirmed the dominant formation of kesterite CZTSSe absorbers, while the MPA-treated samples exhibited larger crystallite sizes, reduced microstrain, and improved local structural ordering. FESEM and AFM observations revealed that MPA incorporation promoted grain coalescence, reduced surface roughness, and produced more compact absorber layers. Conductive AFM further revealed that the MPA-treated films exhibited a more spatially connected current distribution, indicating improved local electrical connectivity and reduced defect-assisted charge transport. Hall effect measurements further showed an increase in carrier concentration from ~10¹⁴ to ~10¹⁹cm⁻³ and a corresponding reduction in resistivity, confirming improved charge transport after MPA incorporation. However, DMF-rich systems exhibited smaller crystallite sizes and greater electrical inhomogeneity than films prepared using balanced solvent compositions, suggesting that an excessive DMF fraction limits long-range crystallite development through changes in precursor coordination and film formation. Among all the samples, M5, prepared with MPA under balanced solvent conditions (MOE: DMF = 50:50), exhibited the most favorable combination of crystallinity, compact morphology, and electrical performance. This study highlights the importance of balancing ligand coordination and solvent chemistry to optimize solution-processed CZTSSe absorbers.

A hierarchical FeCo₃S₄@gC/rGO (Fe-Co-S@gC/rGO) hybrid nanocomposite was synthesized through a MOF-assisted solution-mediated assembly and two-step thermal treatment strategy for supercapacitor applications. The resulting architecture integrates reduced graphene oxide (rGO), graphitic carbon (gC), and cobalt sulfide-based nanostructures to improve electrical conductivity, electrolyte accessibility, and structural stability. Structural characterization confirmed the formation of a porous Fe-Co-S@gC/rGO framework with uniformly distributed Fe, Co, S, C, N, and O species. Electrochemical measurements showed that the optimized Fe-Co-S@gC/rGO electrode delivered a high specific capacitance of 1827 F g⁻¹ at 0.5 A g⁻¹ and retained strong cycling durability. An asymmetric supercapacitor assembled using Fe-Co-S@gC/rGO as the positive electrode and rGO as the negative electrode exhibited favorable energy-storage performance and long-term stability. The device delivered 974.1 F g⁻¹ at 0.5 A g⁻¹ and achieved a high energy density of 541.2 Wh kg⁻¹ at a power density of 8213.4 W kg⁻¹. Additionally, long-term durability was confirmed over 12,000 charge–discharge cycles and 10,000 voltammetry cycles. The enhanced electrochemical behavior is attributed to the combined effects of hierarchical porosity, conductive graphitic carbon/rGO networks, and abundant redox-active sites. These results suggest that Fe-Co-S@gC/rGO is a promising electrode material for advanced supercapacitor applications.

Iridium bis(phenylpyridine)(bipyridine) complex, Ir(ppy)₂(bpy)⁺, which exhibits outstanding photophysical and photochemical properties as a photosensitizer, was immobilized on 2,2′-bipyridine-bridged mesoporous organosilica (BPyPMO) to afford Ir-BPyPMO. Successful immobilization of the iridium complex within the PMO framework was confirmed by X-ray absorption fine structure analysis. Ir-BPyPMO exhibited a characteristic UV–vis diffuse-reflectance spectrum with a metal-to-ligand charge-transfer (MLCT) band at a wavelength comparable to that of the corresponding MLCT band of the homogeneous Ir(ppy)₂(bpy)⁺ complex, indicating that the photophysical properties of the iridium complex were retained after immobilization. Under visible-light irradiation, Ir-BPyPMO functioned as an efficient heterogeneous photosensitizer for the aza–Henry reaction through C–H functionalization of 2-phenyl-1,2,3,4-tetrahydroisoquinoline. Furthermore, co-immobilization of a rhenium tricarbonyl complex on Ir-BPyPMO afforded Re-Ir-BPyPMO, which efficiently catalyzed CO₂ reduction in the presence of a sacrificial electron donor. These results demonstrate that the immobilized iridium complex functions effectively as a heterogeneous photosensitizer and highlight the potential of BPyPMO as a versatile platform for constructing photocatalytic systems.

Zinc oxide (ZnO) is a widely investigated semiconductor owing to its versatility in electronic and optoelectronic applications. However, its intrinsic diamagnetism and relatively low electrical conductivity limit its performance in advanced electronic and spintronic systems. In this work, we investigate the effect of nickel-induced hybridization in ZnO nanoparticles with a nominal Ni concentration of 20%, focusing on the resulting structural, electrical, dielectric, and magnetic properties. The incorporation of Ni ions into the ZnO lattice promotes hybridization between Ni 3 d and O 2p orbitals, leading to modifications in the electronic structure and defect landscape. This effect results in a significant enhancement of electrical conductivity, with a thermally activated conduction mechanism characterized by a low activation energy of approximately 84 meV, indicating facilitated charge transport via defect-related states. Magnetic measurements reveal a transition from diamagnetic to superparamagnetic behavior, with a saturation magnetization of 6 emu/g at 5 K, decreasing to 1.5 emu/g at 300 K. Overall, the observed hybridization-driven tuning of electrical and magnetic properties highlights the potential of Ni-doped ZnO nanoparticles for applications in electronic devices, spintronics, gas sensing, photocatalysis, and magnetic hyperthermia.

ZrO₂/SiO₂ composite film was prepared on the surface of zirconium hydride by anodic oxidation+sol-gel sealing composite process to solve the problem of insufficient hydrogen resistance caused by defects such as micropores and microcracks in the anodic oxidation film of zirconium hydride. Using tetraethoxysilane (TEOS) as precursor, polyvinyl alcohol (PVA), silane coupling agent KH570 and A171 were introduced to regulate the sol structure, and the film was densified and stabilized by stepwise heat treatment. The microstructure, composition, phase, thermal behavior and molecular structure of the composite film were systematically analyzed by means of SEM, EDS, XRD, TGDSC and FTIR. The thickness, adhesion, microhardness and hydrogen resistance of the film were tested to reveal the defect repair mechanism and hydrogen resistance mechanism. The results show that PVA and silane coupling agent can significantly refine the sol particle size, improve the film density and interfacial bonding strength. The optimized composite film has a thickness of 27.15μm, a binding force of 70.74 N, a microhardness of 457HV, and an initial dehydrogenation temperature of 710°C, showing excellent mechanical properties and high-temperature hydrogen resistance. The composite film forms a double-layer protective structure through anodic oxide layer support + sol-gel layer sealing, which blocks cracks and pores macroscopically. At the micro level, O-H and C-H chemical bonds are used to capture hydrogen atoms and inhibit diffusion, so as to achieve high-efficiency hydrogen resistance modification of zirconium hydride.Distinct from traditional single-layer hydrogen-resistant coatings, this work constructs a double-layer barrier via anodic oxidation and ternary PVA/KH570/A171 modified sol-gel, and reveals a dual-scale hydrogen resistance mechanism. This process can provide theoretical basis and technical reference for the surface strengthening of zirconium hydride based hydrogen barrier materials in nuclear industry and space energy field.

Their high porosity, high surface area, and low density render resorcinol-formaldehyde (RF) aerogels attractive precursors to their carbon analogs which have interesting applications, for instance in adsorption, catalysis, or electrochemical energy storage. While they are conventionally produced by pyrolysis as monoliths in a laboratory scale, a large-scale production would be more facile if they were produced in the form of microbeads. The direct bead formation of RF solution by the dropping method is limited because of their inability to preserve the spherical shape until gelation due to the low viscosity of RF solution. Therefore, within this work, we aimed to improve the viscosity by adding the polysaccharide-based thickener xanthan gum (XG) to the RF solution and pre-gelling them, followed by dropping into an acid bath for rapid gelation. We were thus able to produce RF aerogel beads (RFB) and subsequently carbon aerogel beads (CB) with diameters ranging from 2.0–2.6 mm. Here, we investigated the physicochemical properties of the resulting RF and CB using various physicochemical techniques by varying the XG concentration and the type of acid gelation bath. N₂ physisorption analysis showed that CBs developed with high surface areas up to 1205 m²/g, micropore volumes up to 0.43 cm³/g and, bulk (tap) density of 0.31 g/cm³. In order to evaluate the use of these CBs for applications such as carbon capture and electrode material, we furthermore investigated their CO₂ sorption capacity, electrical conductivity, and mechanical properties. These findings presented in this work demonstrate the promising potential of the carbon aerogel microbeads for such applications.