Journal of Sol-Gel Science and Technology最新文献

Poly(vinyl alcohol) (PVA)/polyethylene oxide (PEO) blend electrolytes incorporating silver nanoparticles (Ag NPs) were fabricated via a conventional solution-casting technique and systematically investigated for their structural, optical, electrical, and dielectric properties. Transmission electron microscopy confirmed that the synthesized Ag nanoparticles exhibit a nearly spherical morphology with a mean diameter of 29.87 nm. X-ray diffraction analysis revealed a progressive reduction in the crystallinity of PVA/PEO blend matrix with increasing Ag nanoparticles content, indicating enhanced amorphous character and strong polymer–nanoparticle interactions. Fourier-transform infrared spectroscopy confirmed interactions between Ag nanoparticles and the hydroxyl and ether functional groups of the blend. UV–visible optical studies demonstrated a concentration-dependent red shift in the absorption edge and a significant reduction in both indirect and direct optical band gap energies, decreasing from 4.99 and 5.30 eV for the pristine PVA/PEO blend to 4.15 and 4.56 eV, respectively, at higher Ag loadings. Electrical and impedance spectroscopy revealed a pronounced enhancement in ionic conductivity upon Ag incorporation, attributed to reduced bulk resistance, increased segmental mobility, and the formation of conductive pathways within the nanocomposite matrix. Furthermore, dielectric analysis showed high dielectric constants at low frequencies governed by Maxwell–Wagner–Sillars interfacial polarization. The combined improvements in structural, optical, electrical and dielectric properties highlight the potential of PVA–PEO/Ag nanocomposite electrolytes for energy storage applications, particularly high-performance dielectric capacitors and multifunctional polymer systems.

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This investigation reports the fabrication and comprehensive functional evaluation of a newly engineered hybrid nanocomposite composed of gallium nitride (GaN) integrated with a poly(3-methylthiophene)-co-poly(indole) (P3MTH–PID) copolymer, synthesized via a straightforward chemical oxidative polymerization route. GaN nanoparticles were prepared using a supercritical ammonia method and subsequently combined with P3MTH–PID nanofibers to form a uniform hybrid structure. Structural and surface analyses confirmed robust π–π stacking interactions between the GaN scaffold and the P3MTH–PID copolymer matrix, which facilitated efficient charge delocalization and ensured homogeneous nanofiber distribution across the GaN interface. The hybrid material exhibited remarkable electrocatalytic sensitivity toward albendazole (ABZ), as demonstrated by differential pulse voltammetry (DPV), achieving a detection limit (DL) of 1.372 × 10⁻⁸ M µA⁻¹ and a quantification limit (QL) of 4.352 × 10⁻⁸ M µA⁻¹. Furthermore, the hybrid displayed excellent photocatalytic performance, enabling complete discoloration of methylene blue (MB) within 30 minutes under UV–visible irradiation, with a kinetic rate constant of 78.66 × 10⁻² min⁻¹. Beyond sensing and photocatalysis, the GaN–P3MTH–PID hybrid also showed significant promise in energy storage applications. In a three-electrode configuration, it delivered a high specific capacitance of 294.25 F g⁻¹ at 1 A g⁻¹, while a symmetric supercapacitor device (2 × 2 cm²) assembled from the same material exhibited comparable capacitance and excellent long-term cycling stability. Collectively, these findings highlight that the GaN–P3MTH–PID hybrid integrates superior electrochemical, photocatalytic, and sensing functionalities with strong stability and biocompatibility, making it a highly versatile candidate for sustainable and multifunctional energy storage and environmental applications.

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The Ba_0.96Nd_0.0267Ti_0.94Sn_0.06O₃ (BNTSO) perovskite ceramics was successfully synthesized via a mixed oxide solid-state route. Our investigation has examined how Nd ion substitution affects the structural, surface morphology, optical and dielectric properties of this compound. Structural analysis by X-ray diffraction confirms the formation of a single-phase cubic structure (space group Pm-3m) with an average crystallite size of 30 nm. Scanning electron microscopy (SEM) was used to analyse the samples’ surface morphology and grain size distribution. Fourier-transform infrared (FTIR) spectroscopy revealed the presence of metal–oxygen (Ti-O) bonds and TiO₆ stretching vibration associated with the barium. Dielectric analysis indicated that both dielectric constants and tangent losses were higher at lower frequencies and decreased as the frequency increased. Dielectric measurements demonstrate a high permittivity at low frequencies due to interfacial polarization and a thermally activated relaxation phenomenon. Impedance spectroscopy, modeled using equivalent circuit analysis, reveals that grain boundaries predominantly govern the conduction process. These findings underline the potential of (BNTSO) for advanced electronic applications, including high-frequency devices and gas sensors. Electrical conductivity studies highlight conduction mechanisms governed by the Small Polaron hopping (SPH) and the correlated barrier hopping (CBH) models across different temperature ranges. The thermal evolution of conduction exhibits semiconductor behavior.

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Normalized spectrum of M″ vs. Frequency at different temperatures.

This work investigates the synergistic impact of iron oxide (Fe₂O₃) nanorods and molybdenum trioxide (MoO₃) nanobelts incorporated into a polyvinyl alcohol/hydroxypropyl methylcellulose (PVA/HPMC) blend via solution casting. The structure–property relationships of PVA/HPMC/Fe₂O₃–MoO₃ nanocomposites were analyzed using XRD, FTIR, UV–Vis spectroscopy, and electrical/impedance measurements. Structural analyses (XRD, FTIR) revealed reduced PVA/HPMC blend crystallinity and enhanced interfacial interactions, confirming effective integration of Fe₂O₃–MoO₃ nanofillers. Optical studies showed increased absorption, a bathochromic shift, and the appearance of a ligand-to-metal charge-transfer band, accompanied by reduced direct and indirect bandgaps due to defect-induced localized states and intensified interfacial charge transfer. Electrical and dielectric measurements indicated significant improvements in AC conductivity, charge transport, and dielectric constant, with the highest value (~908) achieved at 2.00 wt% nanofillers loading. Overall, the synergistic incorporation of Fe₂O₃ and MoO₃ nanofillers significantly enhances the optical, dielectric, and electrical performance of the PVA/HPMC matrix, making these nanocomposites promising for optoelectronic devices, flexible capacitors, and solid-state energy-storage applications. In addition, their improved dielectric response and charge transport characteristics suggest potential use in flexible sensors, electromagnetic interference shielding materials, and smart wearable electronic systems.

This study investigates the removal of methylene blue (MB) dye from water using a cost-effective, reusable, and efficient iron oxide-doped Xanthan-gum xanthate-based hydrogel nanocomposite (XNH@Fe₃O₄ NC). The nanocomposite was synthesized by doping optimized Xanthan-gum xanthate-based hydrogel (XNH; synthesised via free radical polymerization method) with Fe₃O₄ nanoparticles. Four synthesized hydrogel grades (XNH-1, XNH-2, XNH-3, and XNH-4) were evaluated based on their swelling ratio (SR), water retention percentage (%WRR), and point of zero charge (∆pHpzc) to identify the optimal grade for dye adsorption. XNH-3 exhibited the highest SR (268.19 g/g) and %WRR (92.03% at 65 °C) in distilled water, along with a negatively charged surface over a wider pH range, making it the most suitable for adsorption of MB dye. Consequently, XNH-3 was used to synthesise XNH-3@Fe₃O₄ NCs via the sol-gel method. The selectivity of Fe₃O₄ nanoparticles (NPs) is attributed to their magnetic properties, which allow for easy separation from the solution using an external magnetic field. Additionally, Fe₃O₄ NPs exhibit a low band gap between the valence band (VB) and conduction band (CB), facilitating electron transfer, thereby acting as a competent photocatalyst for the degradation of dye. The nanocomposite achieved a maximum MB removal of 97.9 (±1.0) % under optimal conditions i.e. (pH 7, temperature 25 °C, contact time 30 min, adsorbent dose 0.5 g/L and initial MB concentration 100 mg/L). The absorption process followed Langmuir isotherm model with adsorption capacity of 208.33 (±1.76) mg/g. Furthermore, the XNH-3@Fe₃O₄ NC demonstrated 87.56% degradation of MB dye under visible light photocatalysis.

Cobalt oxide nanoparticles (Co₃O₄ NPs) were synthesized using an eco-friendly green synthesis approach employing Aegle marmelos plant extract as a natural reducing and capping/stabilizing agent. UV–Vis spectroscopy confirmed the successful formation of Co₃O₄ NPs_, exhibiting a band gap energy of 2.1 eV. XRD analysis verified the crystalline nature of the nanoparticles, while FE-SEM revealed a rock-like shape with an average particle size of 60.50 nm. The biosynthesized Co₃O₄ NPs demonstrated excellent antibacterial activity, showing maximum zones of inhibition (20 mm) against S. saprophyticus, E. coli, and E. faecalis, with the least activity (12 mm) observed against S. typhimurium. Furthermore, the nanoparticles exhibited notable antioxidant activity (8.8%) and significant interaction with calf thymus DNA, suggesting potential genotoxic modulation. Furthermore, the Co₃O₄ NPs successfully degraded the pharmaceutical compound ciprofloxacin, demonstrating their photocatalytic ability. These findings highlight the multifunctional potential of green-synthesized Co₃O₄ NPs for biomedical, environmental, and therapeutic applications, warranting further exploration.

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The objective of the present study is to synthesize and investigate the local atomic structural, magnetic, electrical, and optical properties of Eu³⁺-substituted R-type hexagonal ferrite (Sr₁₋_xEu_xMn₂Fe₄O₁₁) with varying Eu concentrations (x = 0.0, 0.02, 0.06, and 0.1), using the sol–gel method. X-ray diffraction (XRD) patterns and X-ray absorption fine structure (XAFS) analysis confirmed the formation of a single-phase structure for all compositions. The incorporation of Eu³⁺ into the R-type hexaferrite influenced the structural parameters, with the positive slope of the Williamson–Hall (W–H) plot indicating the presence of tensile strain in the lattice. The magnetic characteristics of the synthesized samples were examined using a vibrating sample magnetometer (VSM), revealing a soft ferrimagnetic nature. The saturation magnetization was found to range from 5.22 to 2.21 emu/g, accompanied by an increase in coercivity from 274.54 to 283.35 Oe. Ferroelectric P–E (polarization–electric field) loops demonstrated a decrease in both saturation and remanent polarization upon Eu³⁺ substitution, indicating the lossy nature of the materials. UV–visible spectroscopy showed broad light absorption in the visible to near-infrared (700–1100 nm) range, suggesting potential applications in photothermal therapy (PTT). The optical band gap values were found to range from 3.22 to 3.40 eV. Furthermore, photoluminescence (PL) spectra exhibited broad emission from the ultraviolet (UV) to the infrared (IR) region, with the x = 0.06 composition presenting the most intense emission peak. Based on these characterizations, the synthesized materials show promise for use in clinical hyperthermia for cancer treatment and in optoelectronic applications.

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In this study, undoped and Nb-doped TiO₂ thin films were successfully synthesized using sol gel and spin coating methods. The influence of Nb doping ratio on the structural, morphological, optical, Fourier transform infrared spectroscopy (FTIR) and electrical properties of Nb:TiO₂ thin films was systematically investigated. Both Raman analysis and X-ray diffraction (XRD) analysis confirmed the formation of anatase phase for all the samples with a preferential orientation along (101) plane and a slight lattice distortions due to Nb incorporation. The crystallite size was reduced from 23.6 nm to19.3 nm with increasing the doping ratio. FESEM images reveal that the surface morphologies of pure and Nb:TiO₂ films are dense, smooth, uniform and homogeneous without cracks or pores. The incorporation of Nb into TiO₂ host lattice was confirmed by electron dispersion spectroscopy (EDS) analysis. The UV–Vis characterization revealed that all films are highly transparent (∼68–87%) and that Nb doping causes the optical band gap energy shrining from 3.73 eV to 3.64 eV. Moreover, The Fourier transform infrared (FTIR) spectroscopy confirms the successful formation of the TiO₂ phase in all samples. The electrical measurement results revealed an improvement in the film’s resistivity and carrier concentration with Nb doping, this was attributed to Nb⁵⁺ions substituting Ti⁴⁺ site causing the free electrons concentration rise.

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The development of highly efficient photocatalysts for the degradation of organic pollutants is critical for addressing environmental pollution challenges. Herein, Zinc Oxide and (Mn-doped ZnO) nanomaterials were synthesized via a facile sol-gel method and evaluated for the photocatalytic removal of 3, 4, 5-trimethoxybenzaldehyde under a visible light source. ZnO and other transition metal oxides are appreciated because they are stable, affordable, and can be used in photocatalysis. However, their reliance on UV light absorption limits their practical applications. The incorporation of Mn into the ZnO lattice, which enhanced visible light absorption and reduced charge carrier recombination, was confirmed by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX), while morphological analysis via scanning electron microscopy (SEM) revealed uniform nanostructures with enhanced surface area. Moreover, crystallite sizes ranging from 20 nm and bandgap energy of approximately 2.78 eV, confirm the successful modification of ZnO’s optical properties. Mn-doped ZnO nanostructures produced via the sol-gel process were tested for photocatalytic degradation of 3,4,5-trimethoxybenzaldehyde under visible light irradiation. The optimized Mn-doped ZnO catalyst exhibited exceptional photodegradation activity, achieving over 90% degradation of 3, 4, 5-trimethoxybenzaldehyde within 120 min, in comparison to pure ZnO, which demonstrated 84% photodegradation activity within 120 min. The enhanced performance was attributable to the excellent separation of charge carriers and increased visible light absorption caused by Mn doping, indicating the potential of synthesized nanostructures for practical wastewater treatment applications.

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Boroaluminates are promising materials for various catalytic applications, particularly due to their tunable acidity and textural properties, although they have not yet reached their full potential. Developing synthetic routes that yield mesoporous structures with high surface areas is crucial for maximizing their performance. Traditional preparation methods (including hydrolytic sol-gel) often struggle to produce highly mesoporous, high-surface-area boroaluminates without the use of templating agents and can lead to heterogeneous elemental distribution. Furthermore, direct comparisons of different non-hydrolytic sol-gel (NHSG) approaches for these materials are limited. In this work, we present an NHSG preparation method for mesoporous boroaluminates, utilizing the alkyl-halide condensation reaction between Al(OⁱPr)₃ and BCl₃, with a 1:1 boron/aluminum precursor ratio. This approach resulted in amorphous xerogels featuring a homogeneous distribution of boron and aluminum atoms within the structure. Our method successfully produced mixed boria-alumina xerogels with high surface areas, reaching up to 600 m² g⁻¹ without the need for any templating agent. We characterized these materials using ¹¹B and ²⁷Al MAS NMR spectroscopy, SEM and STEM-EDS microscopy, N₂ porosimetry, thermogravimetry, ICP-OES and XPS elemental analysis and ammonia-TPD. Additionally, we provide a comparative analysis with boroaluminates prepared by other non-hydrolytic sol-gel reactions and demonstrate their practical utility in catalysis through ethanol dehydration (with >83% ethanol conversion at 275 °C), producing both ethylene and diethyl ether. This work offers a promising route for synthesizing mesoporous boroaluminates for catalytic applications.

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