Journal of Sol-Gel Science and Technology最新文献

This study presents the synthesis, characterization, and multifunctional applications of Calcium carbonate–silica (CaCO₃@SiO₂) core–shell nanocomposite (NCs) aimed at addressing environmental challenges. The NCs were synthesized using a co-precipitation and sol-gel method, resulting in core-shell structures that were thoroughly characterized through various techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-Visible spectroscopy. The catalytic performance of the nanocomposites was evaluated for CO₂ methanation, achieving an impressive conversion rate of 87.84% at 360°C, demonstrating their potential for sustainable carbon utilization. Additionally, the photocatalytic activity was assessed through the degradation of Evans Blue dye and Fenitrothion pesticide under solar irradiation, with removal efficiencies of 99.4% and 99.92%, respectively, within 140 minutes. In-silico molecular docking studies indicated strong binding affinities with key bacterial and viral protein targets, suggesting potential antibacterial and antiviral applications. The results highlight the multifunctional capabilities of CaCO₃@SiO₂ NCs as promising materials for carbon capture, water purification, and biomedical applications, paving the way for innovative solutions in environmental and energy sectors.

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This study presents a green-engineered heterostructure photocatalyst, CuWO₄@MoS₂, synthesized via a hydrothermal route using ginger extract, for efficient degradation of methylene blue (MB) dye under visible light. The novelty lies in combining the redox-rich CuWO₄ with MoS₂ to form a synergistic heterojunction using an eco-friendly method that eliminates the need for harmful chemicals. X-ray diffraction (XRD) confirmed the successful formation of a CuWO₄@MoS₂ heterostructure without secondary phases, while crystallite size enlargement and reduced dislocation density indicated improved crystallinity. Fourier-transform infrared spectroscopy (FTIR) verified the retention of key functional groups and the formation of strong interfacial bonds. Energy-dispersive X-ray spectroscopy (EDX) affirmed the elemental purity and hybridization of both components. Scanning electron microscopy (SEM) revealed uniform CuWO₄ particle anchoring onto MoS₂ sheets with reduced grain size up to 43 µm. UV-Vis spectroscopy showed a red shift in absorption edge and a narrowed bandgap (2.70 eV), enhancing visible-light utilization. CuWO₄@MoS₂ exhibited suppressed PL intensity and a smaller EIS arc radius, confirming reduced charge recombination and enhanced charge transfer. The composite achieved 89% dye degradation efficiency, outperforming individual materials, and followed zero-order and pseudo-first-order kinetics with the highest rate constant. This green-fabricated CuWO₄@MoS₂ shows promise as a sustainable photocatalyst for wastewater treatment and provides a template for future development of eco-friendly heterostructures with enhanced photoreactivity.

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Explanation: Ginger extract enables a green, sustainable, and biocompatible synthesis of CuWO₄@MoS₂ with enhanced stability and eco-friendly characteristics.

The process of photocatalytic oxidation has been extensively studied and used to break down organic contaminants in air and water. Recent technological developments have combined photocatalysis (PC) and fuel cells (FC) to create photocatalytic fuel cells (PFC), which allow wastewater treatment and power generation to occur simultaneously. The PFC systems use the organic contaminant as fuel in the fuel cell component, which breaks down when light strikes the photoanode. The voltage differential between the two electrodes drives the movement of photoexcited electrons. Consequently, the solar efficiency is increased by significantly reducing the unwanted recombination of electrons and holes. During the wastewater treatment process, the chemical energy contained in the organic impurities is extracted and transformed into electrical energy that can be used. Carbon dioxide may be reduced, and hydrogen can be produced using photoelectrochemical technology. Numerous approaches, including dual-photoelectrode configurations, innovative cell designs, sophisticated visible-light photoelectrodes, and effective control techniques, have been studied to enhance PFC mechanisms. The concepts and technological advancements in PFC will be examined in this review, with a focus on innovative cell designs. Finding viable research avenues to further develop PFC technology is facilitated by a deeper comprehension of PFC.

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This pioneering study presents the synthesis and comprehensive evaluation of bare and metal-doped Ag₂S nanocrystals (NCs) as multifunctional agents with potential applications in antibacterial, antioxidant, and anticancer therapies. The incorporation of manganese, nickel, cobalt, and zinc into Ag₂S NCs resulted in a notable enhancement of their bioactivity, representing a novel approach in nanomaterial design. The antibacterial assessments revealed that Mn:Ag₂S NCs were the most potent candidate, exhibiting exceptional activity against S. aureus and E. coli, with the lowest MIC values recorded at 1.28 mg/mL and 1.08 mg/mL, respectively. The antioxidant studies demonstrated that the Mn:Ag₂S NCs exhibited remarkable free radical scavenging and ferric reducing capacities, with the lowest IC₅₀ values (22.69 µg/mL for DPPH and 61.31 µg/mL for FRAP) underscoring their potential to mitigate oxidative stress. Importantly, cytotoxicity assays revealed that Ni:Ag₂S and Mn:Ag₂S nanocrystals selectively inhibited the proliferation of human colon cancer cells (HT-29), achieving IC₅₀ values of 61.51 µg/mL and 90.12 µg/mL, respectively. Furthermore, these NCs demonstrate reduced toxicity towards mouse fibroblast cells (L929). This selective cytotoxicity indicates the potential of these agents in targeted cancer therapies, thereby reducing damage to healthy tissues. To the best of our knowledge, this is the first study to systematically explore the synergistic effects of metal doping on the multifunctional properties of Ag₂S NCs. These findings provide a robust basis for further in vivo studies and offer new avenues for the development of safe and effective nanomaterials in biomedical applications, particularly as antimicrobial, antioxidant, and anticancer agents.

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In this paper, we present the synthesis and characterization of hybrid coatings based on silica modified using polydimethylsiloxane containing methyl and methylphenyl groups in its linear chain. The synthesis was conducted using a polycondensation catalyst (di-butyl dilaurate tin; DBTL) and in the absence of a solvent. Infrared spectroscopy indicates the formation of two silica clusters and the presence of the main functional groups. In addition, TGA–DSC analysis corroborated the formation of a polysiloxane chain bonded to the formed silica. Moreover, atomic force microscopy (AFM) revealed a modification in the microstructure of the coatings. Consequently, the functional group has been demonstrated to modify the anticorrosive behavior of the ceramic. This conclusion is corroborated by the results obtained by EIS, which demonstrate that the R_estimated, defined as the diameter of the semicircle in the Nyquist diagram, increased by 10–16 times for uncoated aluminum, 28–33 times for the SiO₂/DMS-CH₃ coating, and 28–33 times for the SiO₂/PDS coating. These findings suggest that the SiO₂/PDS coating exhibits a greater anticorrosive capacity than the SiO₂/DMS-CH₃ coating, particularly as the siloxane chain content in the ceramic increases. Moreover, the PDS functional group (CH₃ and phenyl) demonstrates a greater effect on the anticorrosive behavior.

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Cerium oxide (CeO₂) nanoparticles (NPs) have gained considerable attention in environmental remediation and the biomedical domain due to their advantageous physicochemical characteristics, such as prominent antioxidant and optical properties. Herein, gadolinium (Gd)-doped CeO₂/carbon nanotube (CNTs) nanocomposites were successfully synthesized by eco-friendly sol-gel and sonication methods. To characterize the synthesized nanoparticles, analytical techniques, including XRD, SEM, EDX, FT-IR, PL, UV–vis, and DLS analysis, as well as cytotoxicity evaluation, were employed. This characterization was achieved through the degradation of phenol red dye and the MCF-7 cell assay. The XRD patterns indicated the presence of a pure cubic phase of CeO₂ NPs. SEM analysis showed the formation of well-defined tubular morphology in Gd-CeO₂/CNT nanocomposites, and EDX confirmed the coexistence of Ce, Gd, O, and C elements. FT-IR analysis identified vibrational stretching bands associated with Ce–O, O–H, and C = C. UV-Vis spectra showed that the band gap energy of CeO₂ NPs was reduced from 3 ± 0.10to 2.5 ± 0.10 eV after the addition of Gd and CNTs doping. PL spectroscopy revealed that Gd incorporation in CeO₂ induced a redshift in absorption and promoted the formation of defect states, while Gd-CeO₂/CNTs nanocomposites stimulated efficient charge transfer activity. Additionally, DLS results further revealed that the agglomeration of CeO₂ NPs was reduced by Gd doping with anchoring of CNTs due to a decrease in dispersibility (PDI). As shown in the photocatalytic results, Gd-CeO₂/CNTs nanocomposites have a higher degradation efficiency (up to 80.3%) of phenol red dye compared to pure CeO₂ NPs. MTT assay-based cell viability tests confirmed that all materials retained over 80% cell viability between 0 and 400 μg/mL, with no cytotoxicity at lower concentrations. The NPs and NCs demonstrated excellent biocompatibility on normal IMR90 cells. These results suggest that Gd-CeO₂/CNTs nanocomposites have significant potential for cancer therapy applications with good biocompatibility on normal cells.

Carbon aerogels derived from organic precursors are gaining attention in various applications, especially in energy storage. On one hand, this paper deals with the substitution of phenolic materials by tannin which could be beneficial to both the bioeconomy and the environment due to its low-cost, bio-based, and non-toxic characteristics. On the other hand, the comparative study aims to explore advantages and drawbacks of both aerogels, their electrical conductivity, morphology, performance in an electrochemical cell, and materials costs. The results illustrate that both nitrogen-doped aerogels exhibit pyridinic and pyrrolic functional groups, while doping with melamine leads to higher nitrogen amount about 5 wt.-% compared against ammonia treatment (1–2.5 wt.-%). RF-based carbon aerogels exhibit almost twice the electrical conductivity of tannin-based carbon aerogels. The electrochemical performance of both carbon aerogels in an electrochemical cell is comparable to literature-reported cases. The capacitance of non-doped aerogels was found to be the highest, reaching 239 F‧g^–1 at a current density of 0.5 A g^–1. Material costs of tannin-based electrodes are slightly lower compared to those based on resorcinol.

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Lead-free double perovskites have emerged as promising alternatives to lead-based absorbers in perovskite solar cells due to their enhanced stability and environmentally benign nature. This study systematically investigates the key parameters influencing the performance of the FTO/ZnO/Cs₂BiAgI₆/CuSCN/Au solar cell, with a primary focus on optimizing its power conversion efficiency (PCE) using the SCAPS-1D software. Variations in electron affinity, impurity concentration, and defect density are found to impact device performance significantly. A lower electron affinity facilitates improved charge transport, thereby enhancing overall device efficiency. An optimal impurity concentration of Cs₂BiAgI₆ at 1 × 10¹⁸cm^–3 yields a maximum PCE of 18.95%. Additionally, increasing the ambient temperature from 300 K to 400 K leads to a decline in PCE from 16.77% to 11.89%. To evaluate the effect of series resistance, its value was varied from 1 to 5 Ω.cm², resulting in a decrease in PCE from 21.20% to 19.21%. The highest quantum efficiency is observed at a short wavelength of 370 nm. The optimized PCE of 21.20% achieved in this study exceeds previously reported values, highlighting the significant potential of Cs₂BiAgI₆-based devices in the development of high-performance, lead-free photovoltaic technologies.

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