Journal of Sol-Gel Science and Technology最新文献

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.

This work added to the increasing efforts to explore innovative materials for the future of photovoltaics, which was important given the solar industry’s pressing need for new and efficient materials. In this study, we revealed the promising optical and photovoltaic capabilities of mono phase lattice of barium ferrite by successfully incorporating Mn²⁺ ions for the first time to the best of our extent. Magnetic Ba_1-xMn_xFe₂O₄ (x = 0.0, 0.2, 0.3, 0.5) nanoparticles have been prepared by sol-gel auto combustion method. BaFe₂O₄ has received a little attention for its photovoltaic potential thus far, with much of its research focused on magnetic, radar absorption, and EMI (electromagnetic interference) shielding applications. Mn at varying substitutional concentration (20–50%) molar fraction was investigated to eliminate the disparity between magnetism and energy conversion encouraged by untapped potential of Mn incorporated ferrite nanoparticles as an innovative photo active material. X-ray diffraction demonstrated a structural transition from orthorhombic Pnma to Pmcn in pure barium ferrite to 20% Mn content, followed by orthorhombic Bb2₁m with 30% and 50% samples resulting in the reduction of crystallite size (43–39 ± 2 nm) with substitution. SEM and EDS settled the formation of sphere-shaped nanoparticles (229–61 ± 5 nm) and supported the presence of Mn with proposed scheme in all samples, respectively. With an increase in Mn concentration, VSM showed a notable improvement (M_s = 1.5–25 emu/g) in magnetism. The structural transition also correlated with increased light absorption and a narrowing of the optical band gap (1.5–2.0 ± 0.02 eV) revealed by DRS. The greenish-yellow portion of the CIE chromaticity diagram corresponded to the 573–576 nm range where visible emission was observed in PL spectra indicating defect levels and effective radiative recombination within the band structure refining charge carrier dynamics. The ferroelectric behavior reflected high leakage current for higher infused Mn samples by multiferroic system. Significantly, Mn-substituted samples showed elevated photo current density in current-voltage (I-V) directing their possibility as multipurpose material. Such optical behavior suggested the material’s potential to effectively absorb visible light and conversion. These results collectively strengthened that Mn infusion competently tailored the structural, magnetic, and optoelectronic characteristics of barium ferrite nanoparticles, hence enabling this combination as an efficient material for PV applications.

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Nitrate contamination poses a severe environmental threat due to its detrimental impact on aquatic ecosystems and human health, necessitating efficient remediation strategies. This study explores the potential of silver-doped titanium dioxide (Ag-TiO₂) nanoparticles as an advanced photocatalyst for nitrate removal from wastewater. Ag doping enhances the photocatalytic activity of TiO₂ by narrowing its bandgap energy and improving charge carrier separation, thereby facilitating efficient nitrate reduction under ultraviolet A (UVA) irradiation. The crystalline structure, morphology, oxidation states, and optical properties of the synthesized Ag-TiO₂ nanoparticles were characterized using various analytical techniques. A series of controlled batch experiments was conducted to investigate the effects of photocatalyst dosage (0.1, 0.5, 1.0, and 2.0 g) and initial nitrate concentrations (10, 25, 50, 80, and 100 mg-N/L) on the photocatalytic reduction process. The results indicate that 1.0% Ag-TiO₂ exhibits superior nitrate removal efficiency (over 97% within 90 min) compared to undoped TiO₂, with predominant conversion to environmentally benign nitrogen gas (N₂) and minimal accumulation of undesired byproducts such as nitrite (NO₃⁻) and ammonium ions (NH₄⁺). The enhanced performance is attributed to the plasmonic effect of silver, which extends the light absorption range into the UVA spectrum and suppresses electron-hole recombination. This study highlights the environmental sustainability of Ag-TiO₂ as an efficient, photocatalytically active material for nitrate remediation, presenting a promising solution for wastewater treatment applications.

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In this report, we used a cost-effective, green, and sustainable synthesis method for zinc oxide (ZnO) nanoparticles (NPs) using Azadirachta indica leaf extract. XRD results confirmed the hexagonal crystalline phase (average crystallite sizes 20–30.5 nm), FTIR identified the main functional groups, SEM revealed rod-like morphology, and EDX confirmed the elemental purity. The UV-vis spectra exhibited a blue shift, indicating a reduction in particle size and an increase in the bandgap. The in vitro and in vivo anti-diabetic activities of the prepared ZnO-NPs demonstrate an increase in glucose adsorption and promote glucose uptake by yeast cells. In diabetic mice, NPs reduced blood glucose levels (274–140 mg/dL), comparable to those of the standard drug (278–134 mg/dL). The heat-induced hemolysis and human red blood cell (HRBC) membrane stabilization assays were used to study the anti-inflammatory activity, showing inhibition rates ranging from 9.2% to 64%, consistent with those of the standard drug (12–67%). Antibacterial activity against E. coli bacteria using the well diffusion method (WDM) exhibited inhibition zones of up to 19.6 mm, comparable to the standard drug’s 21.6 mm. The overall findings of the study highlight the biomedical potential of ZnO-NPs using Azadirachta indica leaf extract.

The production and characterization of MoS₂@({{Co}}_{3}{S}_{4}) nanocomposites have primary importance in the enhanced uses of electrolytic energy storage. The utilization of Camellia sinensis (green tea) extract as a natural, green reducing and stabilizing agent in a hydrothermal synthesis method is what makes this work novel. Packed with flavonoids and polyphenols, the extract reduces the need for dangerous chemicals while promoting the regulated nucleation and development of the MoS₂@({{Co}}_{3}{S}_{4}) composite. The successful creation of a crystalline MoS₂@({{Co}}_{3}{S}_{4}) heterostructure with a 25.7 nm crystallite size was verified by X-ray diffraction (XRD). The presence of distinctive Co–S and Mo–S bonds, as well as surface hydroxyl and organic functional groups, was further confirmed by FTIR analysis, suggesting successful integration and surface functionalization. The redox peaks were detected by cyclic voltammetry (CV), supporting pseudocapacitive behavior. Excellent electrochemical performance was shown by galvanostatic charge-discharge (GCD) experiments, which demonstrated an 865 F/g maximal specific capacitance at 0.8 A/g. Following cycling, electrochemical impedance spectroscopy (EIS) demonstrated enhanced ion transport and low charge transfer resistance. High dielectric constant and AC conductivity were found in the dielectric characterization, confirming its multifunctionality. The present MoS₂@Co₃S₄ material can be considered an advanced green-synthesized electrode material due to its high specific capacitance (865 F/g at 0.8 A/g), low charge-transfer resistance, and enhanced dielectric properties, which collectively represent a significant improvement over many reported MoS₂ and Co₃S₄-based materials.

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Synergistic electrochemical and structural properties of MoS₂@Co₃S₄ nanocomposite for high-performance energy storage.