Cerium oxide (CeO₂) nanoparticles were fabricated through a green route using Syzygium cumini (SC) leaf extract as a reducing and capping agent. The as-synthesized CeO₂ nanoparticles were incorporated into a polyaniline (PANI) matrix to form CeO₂/PANI nanocomposites via in situ chemical oxidative polymerization. A series of CeO₂/PANI nanocomposites with varying nanoparticle loadings (1–7 wt
Controlling crystallite size and phase purity remains a persistent challenge in the sol–gel synthesis of alumina (Al₂O₃) nanoparticles, as prior studies have largely examined process parameters in isolation rather than through integrated multi-response optimization. This study aimed to identify the combination of precursor material, calcination temperature, and calcination time that minimizes both crystallite size and thermogravimetric mass loss in sol–gel-derived alumina synthesis. Nine samples were prepared using aluminum nitrate, aluminum sulfate, and aluminum chloride precursors via the Taguchi L9(3³) orthogonal array. Calcination was performed at 800–1200 °C for 3–6 h. Samples were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Grey Relational Analysis (GRA), along with the Taguchi signal-to-noise ratio, was used to simultaneously optimize both responses. XRD identified different alumina phases (α, θ, δ, and γ) with crystallite sizes ranging from 5.2 to 26.5 nm, while TGA mass loss ranged from 4.90
The aim of the study was to produce polymeric films as a semi-solid matrix for the loading of a binuclear Cu(II) complex made by maleate and phenanthroline ligands complexed with Cu2+ ions ([Cu2(Phen)2(Mal)2]⋅2H2O⋅CH3OH), and to characterize the structural, optical, thermal, and biological properties of the obtained crystal-loaded films. The films were prepared by adding the synthesized polycrystal at concentrations of 0.5, 1, and 2
Identifying promising double perovskite (DPs) hydride materials for efficient hydrogen storage is an important issue for hydrogen-based energy scenarios. Herein, we examine the structural, hydrogen storage, electronic, mechanical, optical, and thermoelectric properties of novel DPs hydrides Rb2CuYH6 and Cs2CuYH6 by using density functional theory. Structural studies revealed a cubic structure having space group 225 (Fm3m) with optimized lattice parameters of 8.70 Å for Rb2CuYH6 and 8.68 Å for Cs2CuYH6. Both compounds exhibit negative formation energies. For hydrogen storage applications, the estimated gravimetric capacities are 1.64 wt
Double perovskite oxides are promising candidates for spintronic and magnetic applications because their magnetic properties can be effectively tailored through ionic substitution. In this work, the effects of non-magnetic Ag+ and magnetic rare-earth Sm3+ substitution at the Ba site of Ba2FeMoO6 were systematically compared for the first time at the same doping level (x = 0.05). Ba2−xAxFeMoO6 (A = Ag, Sm; x = 0.0 and 0.05) compounds were synthesized using the sol–gel method to investigate the influence of these dopants on the structural and magnetic properties of Ba2FeMoO6. The crystal structure, morphology, chemical states, and magnetic properties were characterized using X-ray diffraction with Rietveld refinement, FE-SEM, FTIR spectroscopy, XPS, and magnetic measurements. Structural analysis confirmed that all samples crystallized in a single-phase cubic structure with the Fm-3m space group. Although Ag+ and Sm3+ substitution did not change the crystal symmetry, slight modifications in the lattice parameters, unit-cell volume, and bond lengths were observed. FE-SEM images revealed an increase in porosity after doping, while FTIR spectra indicated changes in the vibrational modes associated with the MoO6 octahedra. XPS analysis confirmed the coexistence of Fe2+/Fe3+ and Mo5+/Mo6+ mixed valence states, which are essential for the double-exchange interaction. Magnetic measurements showed that both doped samples exhibited lower magnetization than the undoped compound. In contrast, Ag+ substitution reduced the magnetic transition temperature, whereas Sm3+ substitution increased it. These variations are attributed to dopant-induced structural distortions and changes in bond lengths, which modify the magnetic exchange interactions. The results provide new insights into the distinct roles of non-magnetic and magnetic dopants in tuning the structural and magnetic behavior of Ba2FeMoO6 double perovskites.
Bismuth(III)-doped 13–93 silicate bioactive glass powders were synthesized via a sol–gel route with Bi₂O₃ contents ranging from 0.1 to 5 wt
Potassium niobate (KNbO3) has shown unique performance in photocatalysis due to its effective strategy for mitigating charge-carrier separation. For instance, KNbO3 (KN) is a ferroelectric semiconductor with some extraordinary photocatalytic properties (i.e., non-toxic, high stability, and chemical inertness). KN serves as a ferro-photocatalyst, offering sustainable solutions to environmental degradation. This review summarizes the fundamental characteristics and ferro-photocatalytic applications of KN and KN-based nanostructures. Initially, various fabrication techniques and structures of KN will be discussed. Subsequently, the review examines the design methods for KN-based photocatalysts to understand their functionality. Recent developments in KN photocatalysts are enabling the synthesis of composites and nanostructures with enhanced surface area and morphology, thereby improving ferroelectric and photocatalytic properties. Finally, we conclude with an outlook on the unique properties of KN and KN-based nanostructures for photocatalytic applications, including organic dye degradation and hydrogen production. In the future, KN-based nanostructures have the potential to be used for CO2 reduction and antibiotic degradation, making them a multifunctional material.
Metal–organic frameworks (MOFs) and ferrites face drawbacks such as poor conductivity and self-aggregation. Optimized synthesis methods partially alleviate these issues, while a complementary strategy is to design nanocomposites that integrate both materials. We engineer three-dimensional hierarchically porous nanoparticles, where graphene nanosheets act as a robust substrate that tightly encapsulates Co-MOF/Fe₃O₄ nanoparticles. This architecture increases active sites, enhances the electrode–electrolyte interfacial area, improves electron conductivity, and prevents aggregation during charge–discharge cycling. The heterogeneous structure optimizes reaction kinetics, while the graphene nanosheets provide abundant electroactive sites, boosting electrochemical performance. Electrochemical measurements show a specific capacitance of 1710 F g⁻¹ at 0.5 A g⁻¹ in a three-electrode configuration. As a supercapacitor electrode, the material delivers 869 F g⁻¹ at 0.5 A g⁻¹, an energy density of 212.2 Wh kg⁻¹ at a power density of 8905 W kg⁻¹, and 96.8
Water pollution from industrial dye effluents remains a critical global concern, necessitating the development of sustainable and high-performance remediation materials. In this work, manganese ferrite (MnFe2O4) nanoparticles were synthesized using banana peel enzymes as an eco-friendly reducing and stabilizing agent and subsequently integrated with multi-walled carbon nanotubes (MWCNTs) to fabricate MnFe2O4/MWCNTs and enzyme-functionalized (MnFe2O4/MWCNTs) nanocomposites. Structural, morphological, electrical, and surface features of the synthesized materials were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), BET, and EIS, confirming phase purity, functional groups, and uniform nanoparticle dispersion. The average crystallite sizes were found to be around 31 nm. The photocatalytic activity of the nanocomposites was systematically evaluated for the degradation of methylene blue (MB) under natural sunlight irradiation. Optimization studies revealed that a 25 ppm MB concentration, a catalyst dosage of 1.25 g/L, neutral pH (7), and 100 min of irradiation yielded the highest degradation efficiency. Among all samples, the enzyme-assisted MnFe2O4/MWCNTs composite achieved the maximum removal efficiency of 91
The valorization of agro-industrial by-products offers a sustainable alternative to conventional synthetic additives in sol–gel processes. This study reports a protein-assisted sol–gel route for the synthesis of α-Al₂O₃ using raw goat milk whey (RGMW) as a bio-based chelating agent. The precursor gel, prepared from aluminum nitrate and citric acid with RGMW incorporation, was calcined between 900 and 1100 °C. Thermal analysis indicated the decomposition of the organic matrix and the onset of α-phase crystallisation above 1000 °C. X-ray diffraction with Rietveld refinement confirmed the formation of single-phase α-Al₂O₃ at 1100 °C with a nanoscale crystallite size. FT-IR analysis supported this transformation through characteristic Al–O vibrational bands. X-ray fluorescence revealed a high Al₂O₃ content (96.27 ± 0.69 wt
BiVO4 was synthesized via the hydrothermal method at different temperatures. Metal oxide (CuO, NiO, Fe2O3) modified BiVO4 nanocomposites were prepared using the impregnation method and then X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and other techniques. The photocatalytic degradation mechanism for nitroaromatic pollutants was analyzed by Liquid Chromatography-Mass/Mass Spectrometry (LC-MS/MS) technique. The results show that metal oxides successfully entered the BiVO4 lattice structure; the composites exhibit strong interactions, narrow band gaps, and small particle sizes, which improve visible-light absorption. Due to the synergistic effect between metal oxide and BiVO4, which causes weak recombination of electron-hole pairs and high photon efficiency. The nanocomposites exhibited significantly enhanced photocatalytic properties under light irradiation. The highest degradation efficiency was obtained with the BiVO4(pH 2-100 ℃) at 100 °C. The addition of CuO to the BiVO4 structure improved the photocatalytic degradation performance of nitroaromatic compounds. Complete degradation of 4-nitrophenol (4-NP) was achieved in 30 min, and 4-nitroaniline (4-NA) was completely degraded in 60 min with BiVO4-5CuO. BiVO4-5CuO nanocomposite exhibits the highest photodegradation rate for 4-NP (1.30 min–1) and 4-NA (1.41 min–1). This work presents the synthesis of a novel nanocomposite, which has a spherical-like morphology, that exceptionally enhances the charge-carrying ability and thereby accelerates the photocatalytic degradation of nitrophenols.
The excessive use of fossil fuels significantly contributes to global warming and environmental damage. A viable solution to these problems is the use of renewable energy sources, especially the clean-energy potential of solar cells. This study investigates the photovoltaic properties of TiO₂ nanoparticles (NPs) combined with three specific natural dyes for dye-sensitized solar cells (DSSCs). TiO₂ NPs were synthesized via a green sol-gel method using Aloe vera extract as a natural reducing and stabilizing agent. The materials were analyzed using XRD, FTIR, FESEM, EDX, Raman, and DRS to investigate its crystal phase, morphology, and optical properties. The results show that the material has a crystallite size of 17 nm and a band gap of 3.1 eV, making it suitable for efficient light harvesting. Thin films of TiO₂ were deposited on FTO substrates through spin coating, resulting in uniform and compact photoanodes that are favorable for dye adsorption. Platinum-coated FTO served as the counter electrode, ensuring high electrocatalytic activity. The assembled DSSCs utilized an iodide/triiodide redox electrolyte in ethylene glycol and were tested under standard AM 1.5 G illumination (100 mW/cm²). Among the natural dyes tested, black mulberry demonstrated the highest power conversion efficiency (PCE) at approximately 1.3
The demand for nanostructured luminescent materials with tunable optical properties and scalable synthesis methods continues to grow due to their relevance in solid-state lighting, displays, and photonic devices. In this study, we report a two-step glycine-nitrate solution combustion method for synthesizing yttrium aluminum garnet (YAG) nanopowders doped with lanthanide ions (Eu3+, Tb3+, Tm3+) to achieve red, green, and blue (RGB) photoemission. The process involves low-temperature combustion at 300 °C followed by calcination in air at 800–1200 °C. Structural and morphological analysis by X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that higher calcination temperatures enhance crystallinity, reduce agglomeration, and lead to the formation of uniform granular morphologies. The optimized temperature of 1000 °C yielded phase-pure YAG with an average crystallite size of 26 nm (Eu3+), 27 nm (Tb3+), and 25 nm (Tm3+), as determined by the fundamental parameters approach. Energy-dispersive X-ray spectroscopy (EDX) confirmed a homogeneous distribution of dopants. Photoluminescence measurements demonstrated strong and well-resolved emission peaks at 460 nm (Tm3+: 1D2 → 3F4), 543 nm (Tb3+: 5D4 → 7F5), and 591 nm (Eu3+: 5D0 → 7F1), with chromaticity coordinates corresponding to pure blue, green, and orange-red emission. The PL behavior was closely linked to the structural features of the host matrix, including lattice symmetry, crystallinity, and defect-induced energy states. This work highlights the effectiveness of glycine-assisted combustion as a rapid and versatile route for producing size-controlled, RGB-emitting YAG nanophosphors. The results contribute to the understanding of structure–property relationships in lanthanide-doped oxide systems and demonstrate potential for use in optical and optoelectronic technologies.
Green synthesis has emerged as an environmentally sustainable strategy for engineering multifunctional nanomaterials with enhanced biomedical performance. In this study, cobalt ferrite (CoFe₂O₄) nanoparticles were synthesized via a self-ignition route using carrot extract (Co-C) and pomegranate juice (Co-P) as eco-friendly reducing and stabilizing agents. X-ray diffraction and Rietveld refinement confirmed the formation of phase-pure inverse spinel CoFe₂O₄ with cubic Fd3̅m symmetry and lattice constants of 8.369 Å for Co-C and 8.367 Å for Co-P. Dynamic light scattering analysis revealed dominant nanoscale hydrodynamic populations centered at 11.83 nm for Co-C and 18.17 nm for Co-P, whereas intensity distributions indicated moderate magnetic agglomeration, with secondary populations extending to 286.47 and 551.47 nm, respectively. AFM analysis showed that the pomegranate-mediated ferrite had significantly lower surface roughness (Ra = 0.244 nm; Rq = 0.318 nm) than the carrot-mediated sample (Ra = 1.04 nm; Rq = 1.31 nm), indicating superior nanoscale smoothness and morphological homogeneity. FESEM and HRTEM investigations confirmed the formation of interconnected nanocrystalline ferrite architectures with extract-dependent morphology and aggregation behavior. Magnetic susceptibility measurements revealed ferrimagnetic ordering, with Curie temperatures decreasing from ∼ 829 K for Co-C to 781 K for Co-P, reflecting weakening A–B superexchange interactions induced by cation redistribution. Anticancer performance against PC-3 prostate cancer and MDA-MB-231 triple-negative breast cancer cells showed concentration-dependent cytotoxicity for both ferrite systems. Co-P nanoparticles exhibited superior anticancer activity, with IC₅₀ values of 1.2 mg/mL for PC-3 and 0.60 mg/mL for MDA-MB-231 cells, compared with 1.8 and 0.75 mg/mL, respectively, for Co-C. The enhanced cytotoxicity of Co-P was attributed to its larger surface area (538.17 m²/g), higher porosity (13.38
We investigate the pyrolysis of a polymer-derived porous SiCO gel through thermogravimetric analysis. Despite using “ultra-pure” (99.999
Due to their bioinspired self-assembly and biocompatibility, protein-based aerogels have drawn growing interest in biomedical applications. With its excellent gelling and self-assembly properties, whey protein isolate (WPI) represents a promising source for the fabrication of biodegradable and homogeneous tunable aerogels. Gelation pH has a significant impact on the morphological homogeneity of protein biomaterials, which is essential for controlling tissue-implant interactions. In this study, WPI aerogels were produced without gelation-induced agents (followed by a supercritical CO2 drying process), and the effect of the gelation pH was investigated by varying its value from 2 to 11. Aerogels with a high fluid absorption capacity ( 760
In this study, diol-bridged octasilicate polymers (Diol-OSs) were synthesized via the dehydrogenative condensation reaction between octakisdimethylsiloxy octasilicate (Q8DMS) and diols such as 2-butyne-1,4-diol (BYD), 1,4-benzenedimethanol (BDM), and diethylene glycol (DEG) in tetrahydrofuran (THF). The reactions were performed in the presence of N,N-diethylhydroxylamine, yielding the corresponding Diol-OSs: BYD-OS, BDM-OS, and DEG-OS. Correlations between the structure and physical properties of Diol-OSs were investigated. The molecular weights of Diol-OSs increased with decreasing diol:Q8DMS molar ratio because side chain conversion by the diol occurred more rapidly at higher initial diol concentration. This process reduced the amount and reactivity of the remaining hydrosilyl groups, thereby decreasing the polymerization rate. Furthermore, at the same diol:Q8DMS molar ratio, the molecular weight increased in the order DEG < BYD < BDM. This trend indicates that the chain length and rigidity of diols influence the molecular weight. Compared with DEG-OS and BDM-OS, BYD-OS exhibited a high degree of crosslinking, indicating the formation of a low-branched linear polymer with intramolecular crosslinks. Homogeneous, transparent, and flexible freestanding films of Diol-OSs were obtained by casting THF solutions of Diol-OSs into TeflonTM Petri dishes, followed by heating. Thermogravimetric-differential thermal analysis of the freestanding films revealed that the Si–O–C bonds in BYD-OS and BDM-OS decomposed more slowly than those in DEG-OS. This phenomenon can be attributed to the restricted thermal motion and stability of the rigid diol structures. The tensile strength and Young’s modulus of the BYD-OS and BDM-OS freestanding films were higher than those of the DEG-OS freestanding films because of the rigid structures of BYD-OS and BDM-OS compared with that of DEG-OS. These results demonstrate that the thermal and mechanical properties of Diol-OSs can be controlled by varying the structure of the crosslinked diol.
Nd3+-substituted Ni0.7Zn0.3Cr0.5Fe1.5-xNdxO4 nanoferrites (0.00 ≤ x ≤ 0.05) were synthesized by the sol–gel auto-combustion route to examine how rare-earth substitution tunes the structural, dielectric, electrical, and magnetic characteristics of Ni–Zn ferrites. X-ray diffraction with Rietveld refinement confirmed the formation of a single-phase cubic spinel structure for all compositions. The larger ionic radius of Nd3+ compared with Fe3+ causes lattice expansion/local strain and indicates preferential incorporation into the octahedral B-site network, as also supported by the Bertaut-type cation-distribution analysis. TEM revealed a progressive reduction in particle size with increasing Nd content, consistent with the observed microstructural evolution. Elemental mapping/EDS supported a uniform spatial distribution of constituent elements across the investigated samples. FTIR spectra showed ferrite-related low-wavenumber metal–oxygen vibrational features, with band-shape modifications attributable to Nd-induced perturbation of the local bonding environment. Dielectric spectroscopy showed the expected dispersion of ε′ and tanδ with frequency; moreover, ε′ and dielectric loss decrease with Nd substitution, suggesting suppression of space-charge/interfacial polarization and reduced charge carrier mobility at grain boundaries. The frequency dependence of σac follows the typical ferrite response and is consistent with a hopping-assisted conduction mechanism; σac decreases with increasing Nd content, indicating inhibited hopping between localized states (e.g., Fe2+/Fe3+). Room-temperature M–H measurements confirmed soft ferrimagnetic behavior for all compositions, while the gradual reduction in saturation magnetization and coercivity with Nd incorporation is correlated with weakened A–B superexchange interactions, magnetic dilution, increased Yafet–Kittel spin canting, and modified anisotropy. Overall, Nd3+ substitution provides a viable pathway to tailor the microstructure and multifunctional response of Ni–Zn–Cr ferrites for high-frequency and low-loss magnetic/dielectric device applications.
This study presents a comprehensive analysis of various hybrid solar cell structures based on copper oxide (CuO, Cu2O) and copper indium gallium selenide (CIGS) configurations. Three different architectures CuO/CIGS, Cu2O/CIGS, and CuO/Cu2O/CIGS were simulated using the solar cell capacitance simulator (SCAPS-1D) to investigate their optoelectronic properties and performance parameters. The influence of key factors including the CIGS absorber layer thickness (0.5–3.0 µm), acceptor density (10¹⁵–10¹⁷ cm⁻³), and defect density (10¹³–10¹⁵ cm⁻³) was systematically analyzed. Energy band diagrams were constructed to elucidate the charge carrier transport mechanisms at the heterojunction interfaces. The results demonstrate that the CuO/Cu2O/CIGS structure exhibits superior performance with a power conversion efficiency of up to 24.2
Photoredox catalysis has developed as an effective and adaptable tool for generating novel synthesis procedures. Among its different variants, heterogeneous photoredox catalysis stands out for many significant energy efficiency benefits. Herein, we examined a ternary TiO2/CDs/g-C3N4 (TCC) heterojunction as a photocatalyst for promoting C(sp3)-O bond formation upon illumination with blue LED light. A 10 wt
