Journal of Sol-Gel Science and Technology最新文献

In the face of surging global energy demands and increasing environmental pollution, the development of efficient energy storage and conversion technologies has become critically important. In this study, a series of three-dimensional transition metal-doped Ni₉S₈/Co₉S₈ nanowire electrode materials were synthesized via a hydrothermal method, and their performance as supercapacitor electrodes and bifunctional electrocatalysts for water splitting was systematically investigated. The electronic structure and morphology of the materials were effectively modulated through doping with Cr, Ce, Fe, Mo, and W, leading to significantly enhanced electrochemical performance. Among them, the Cr–Ni₉S₈/Co₉S₈–0.04 electrode, with a Cr doping concentration of 0.04 mM, exhibited an areal specific capacitance of 1128 C cm^-2 at 1 mA cm^-2 and a gravimetric specific capacitance of 485 C g^-1 at 1 A g^-1. As an electrocatalyst, it delivered overpotentials of 227.6 mV for the oxygen evolution reaction (OER) and 117.4 mV for the hydrogen evolution reaction (HER) at 10 mA cm^-2. Further comparative analysis of the effects of different transition metal dopants revealed that Mo-Ni₉S₈/Co₉S₈-0.04 exhibited the best overall performance, with OER and HER overpotentials reaching 161.6 mV and 125.4 mV, respectively. Additionally, its gravimetric and areal specific capacitances reached 674.5 C g^-1 at 1 A g^-1 and 1834 C cm^-2 at 1 mA cm^-2. Moreover, the Cr-Ni₉S₈/Co₉S₈-0.04 electrocatalyst required only 1.42 V to drive a current density of 10 mA cm^-2 in overall water splitting, demonstrating excellent bifunctional catalytic activity. This study provides a novel strategy for synergistically modulating the electrochemical properties of sulfide composite materials through multi-element doping.

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This paper reports the preparation of a series of three-dimensional transition metal-doped Ni₉S₈/Co₉S₈ nanowire electrode materials via a hydrothermal synthesis method, and systematically investigates their performance as bifunctional materials for supercapacitor electrodes and electrocatalytic water splitting.

In this study, AgFe₂O₄/ZnO composites were synthesized, characterized, and evaluated for their photocatalytic performance. XRD analysis confirmed the formation of crystalline ZnO, AgFe₂O_4, and AgFe₂O₄/ZnO composites, with calculated crystallite sizes of 7, 8, and 10 nm, respectively. SEM and TEM analyses showed a uniform particle distribution with minimal agglomeration and well-defined interfaces, indicating stable morphology and effective particle integration. EDS and XPS confirmed the homogeneous distribution of Zn, Fe, Ag, and O elements, supporting efficient charge transfer. PL analysis showed reduced emission intensity in the composite, suggesting suppressed electron-hole recombination and enhanced charge separation due to the heterojunction between AgFe₂O₄ and ZnO. Photocatalytic tests demonstrated that the AgFe₂O₄/ZnO composite achieved over 80% degradation efficiency for organic pollutants within 120 minutes, outperforming pure ZnO. Recyclability tests indicated that the composite retained over 97% of its efficiency after ten cycles, demonstrating long-term stability. The scavenger experiments identified •OH and •O₂^- radicals as the principal reactive oxygen species, confirming their central role in the photocatalytic degradation pathway. VSM analysis revealed weak ferromagnetism, enabling efficient magnetic separation and enhancing the material’s reusability in photocatalytic applications. The novelty of this work lies in the synthesis of AgFe₂O₄/ZnO heterojunction nanocomposites, which have not been previously reported in the literature. These materials exhibit enhanced charge separation and excellent stability for repeated photocatalytic applications. These findings suggest that AgFe₂O₄/ZnO composites are promising materials for sustainable wastewater treatment through photocatalytic degradation of organic pollutants.

As dangerous vectors, mosquitoes pose a serious risk to both human and animal populations worldwide by transmitting dangerous viruses into uninhabitable areas. Because of the emergence of insecticide resistance, controlling the use of synthetic pesticides is essential. S. diastaticus was used in this investigation for the actinobacterial-mediated biosynthesis of Se-NPs. The biosynthesized Se-NPs were characterized using a variety of techniques, including UV, XRD, FT-IR, SEM with EDX, TEM, DLS, and zeta potential. The biosynthesized Se-NPs were effective against C. quinquefasciatus, A. stephensi, and A. aegypti, with LC₅₀ values of 8.13 µg/mL, 9.36 µg/mL, and 13.71 µg/mL, respectively. The highest concentration of Se-NPs revealed high pupicidal activity and increased larval pupal duration against all three mosquito species. The effect of Se-NPs considerably increased the SOD and GPx levels but drastically decreased the AChE and GST level after 24 h of treatment. Histopathological analyses of the treated larvae revealed damaged epithelial cells, peritrophic membranes, and gut cells as compared to the control group. Additionally, A. salina showed low mortality. Conclusively, the biosynthesized Se-NPs using S. diastaticus were used as a potential biopesticide for controlling C. quinquefasciatus, A. stephensi, and A. aegypti.

Distributed Bragg reflectors (DBRs) are essential components in advanced optoelectronic and optical devices. Improving the optical properties of these multilayer structures is at the forefront of research because of their potential use in a variety of sectors, such as solar cells, lasers, sensing and photonics. Sol-gel film deposition is a well-established route for the realization of high-quality optical layers with controlled composition, thickness and optical properties. By using the sol-gel method, SiO₂/2% at. Nd: TiO₂ samples were prepared, with the aim to increase the reflectivity in a broad optical region and to provide specific spectral emissions related to Nd³⁺ ions. The prepared samples have been characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), UV-Visible spectrophotometry, and Photoluminescence (PL). The X-ray analysis revealed that all the samples exhibit an anatase phase, with crystallite sizes ranging from 5.13 to 12.51 nm. AFM topography showed a flat and homogeneous surface with a root mean square (RMS) roughness ranging from 0.19 to 0.28 nm. UV-vis spectrophotometry revealed a low transmission of 0.3% by using only a few alternating layers. Finally, PL analyses reported the active role of Nd³⁺ ions as optical emitters. All these results indicate that the DBRs are promising to be good for advanced optical applications.

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In the present study, In₂O₃:Ti (0,1,2,3,4 and 5 wt%) thin films were prepared by a nebulizer spray pyrolysis technique. Structural analysis performed using XRD diffraction analysis confirmed the formation of In₂O₃:Ti thin films exhibiting a cubic structure with no additional phases, confirming substitutional doping. The lattice constant and unit cell volume decreased with increasing dopant concentration due to the smaller size of the Ti(IV) ion compared with the In(III) ion. FESEM images confirm uniform distribution of fine particles with high surface roughness and porosity for In₂O₃:Ti (3%) thin film, aiding efficient receptor function. UV-Vis spectroscopic analysis revealed that the optical band gap was modulated by changes in dopant concentration, attributed to alterations in the Fermi level and electronic structure of the semiconductor induced by the dopant. The In₂O₃ : Ti (3%) thin film showed a band gap of 3.57 eV indicating a blue-shift which could be attributed to the Burstein-Moss effect. Photoluminescence studies revealed characteristic emission lines in the visible region signifying the presence of oxygen vacancies in the sample. Pristine In₂O₃ sensors showed a detection limit of 5 ppm for ammonia. In₂O₃ : Ti (3%) sensor demonstrated a gas response of 197 to 250 ppm ammonia gas concentration. The response and recovery times of 5 s and 15 s illustrate the quick response of the sensor to ammonia gas. Linear response to the target gas ammonia over the concentration range from 50 ppm to 250 ppm, selectivity to ammonia over other gases against which the sensor was tested, and linear response to the target gas in various relative humidity environments with good stability characteristics make In₂O₃ : Ti (3%) a good choice of material for ammonia gas sensor applications.

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Perovskite-type ceramic materials represent a highly versatile class of functional oxides with applications spanning electronics, energy conversion, catalysis, and environmental remediation. Among the available synthesis strategies, sol–gel processing offers distinct advantages, including molecular-level compositional control, low-temperature crystallization, and the ability to tailor complex architectures. This review consolidates recent progress in sol–gel synthesis of ceramic perovskites, emphasizing the interplay between structural features, phase stability, and performance optimization through doping, nanostructuring, and templating. Particular attention is given to mechanistic insights into sol–gel chemistry, from hydrolysis–condensation kinetics to gel-to-perovskite phase transitions, and their implications for microstructure engineering. The review also addresses emerging approaches for scalable manufacturing, such as advanced templating and low-thermal-budget processing, and critically evaluates current challenge including phase purity, scalability, and environmental impact while outlining future research directions for translating sol–gel-derived perovskites into next-generation functional devices.

In this study, binary alkali-activated pastes based on volcanic ash from Mount Etna (Italy) and borosilicate waste glass were synthesized for the first time using potassium hydroxide (KOH) at different molarities (i.e., 7 M and 9 M) and moderate temperature (60 °C). This work aims to define how the reactants involved in the mix design, specifically the solution concentration and solid proportions of the waste precursors, influence the final microstructure and subsequently their physical and mechanical properties. For this purpose, a multidisciplinary approach, including mineralogical, molecular, chemical, and morphological investigations, was applied to elucidate these properties. The physical-mechanical parameters, including density, uniaxial compressive strengths, porosity, pH, and leaching resistance, determined by boiling tests, were quantified. Increasing KOH molarity from 7 M to 9 M contributes to the formation of a more stable Si-O-Si/Al network, enhancing the compressive strength resistance (~21 to 23 MPa) and reducing both weight loss (~7 to 9%) and the open porosity (~20%). The combined effect of higher molarity and waste glass proportion positively influenced the mechanical response, as a result of the formation of a denser and more compact microstructure. Results confirmed that sustainable materials can be produced using potassium-based binders made from volcanic ash and waste glass.

This study fabricated a solar-sensitive InVO₄-g-C₃N₄ photocatalyst using an ultrasound-assisted wet impregnation technique. Characterization with XRD, FTIR, FE-SEM, UV-vis DRS, PL, and electrochemical impedance revealed that the InVO₄-g-C₃N₄ composite decreased the energy gap from 2.76 eV to 2.66 eV compared to bare g-C₃N₄ nanosheets. Additionally, the decreased photoluminescence intensity upon InVO₄ incorporation indicated efficient charge carrier separation and transport. The performance of the material was evaluated using photocatalytic water splitting with triethanolamine as a hole scavenger. The optimal 6 wt.% InVO₄-g-C₃N₄ composite exhibited a remarkable six-fold increase in hydrogen generation rate (1356 μmolg^-1h^-1) compared to pure g-C₃N₄. Notably, the optimal catalyst shows a solar-to- hydrogen (STH) efficiency of 1.37%. At the InVO₄-g-C₃N₄ interface, enhanced solar light absorption and effective charge carrier separation are responsible for this notable improvement in photocatalytic performance.

Based on industrial waste recycling, calcium silicate hydrate (CSH) powder was hydrothermally synthesized using carbide slag and silica fume from processes of hydrated acetylene and ferrosilicon alloy smelting with the mass ratio of 1:1. To address practical limitations of CSH powder as an adsorbent (e.g., particle loss, partial blocking and difficult separation), sodium alginate (SA) was introduced to fabricate SA/CSH composite gel beads and realize CSH immobilization. It was concluded that such gel entrapment did not impair Cu²⁺ and Ni²⁺ removal performance of CSH powder. When the mass ratio of CSH to SA was 0.5, Cu²⁺ and Ni²⁺ maximum adsorption capacities were up to 208.5 mg/g and 147.0 mg/g, respectively, with an initial concentration of 300 mg/L at 313 K under pH 6, in line with the fitting of the Langmuir isothermal model. And the kinetics were well fitted by the Ho quasi-second-order model. The coexisting Na⁺, Mg²⁺, and Ca²⁺ gradually weakened Cu²⁺ and Ni²⁺ adsorption with the increase in ion concentration. A large amount of Ca²⁺ active sites in SA/CSH gel promoted the chemisorption of Cu²⁺ and Ni²⁺ through ion exchange. In addition, functional groups such as COO-, -O-, and -OH in gel beads fully exerted synergistic complexation. A combined mode for SA/CSH regeneration using 0.02 mol/L EDTA-2Na elution coupled with 5 wt % CaCl₂ for Ca²⁺ replenishment achieved more than 85% of recovery rate after three cycles. Such SA/CSH gel thus presents a promising alternative for heavy metal removal from wastewater.