Journal of Inorganic and Organometallic Polymers and Materials最新文献

A medium-entropy spinel ferrite, Zn_0.2Cd_0.2Mn_0.6Fe₂O₄, was synthesized via the sol-gel method using polyvinyl alcohol (PVA) as a surfactant. The resulting material was thoroughly characterized using XRD, ATR-FTIR, XPS, HRTEM, FESEM, EDS, and BET analyses. XRD analysis confirmed the successful synthesis of single-phase nanocrystalline powders exhibiting a cubic spinel structure (Fd-3 m), with an observed increase in the lattice parameter. XPS analysis reveals the incorporation of Zn²⁺ and Cd²⁺ into the Zn_0.2Cd_0.2Mn_0.6Fe₂O₄ lattice, along with the coexistence of Mn²⁺/Mn³⁺ and Fe²⁺/Fe³⁺ redox species. These mixed-valence states contribute to the formation of heterojunctions, which enhance the hydrogen evolution reaction (HER) activity and stability. FESEM imaging revealed granular and uneven surface morphology, while HRTEM analysis confirmed the presence of compact, irregularly shaped nanogranules. Zn_0.2Cd_0.2Mn_0.6Fe₂O₄ exhibited a mesoporous structure, characterized by a surface area of 36.63 m²/g and a pore volume of 0.088 cm³/g. The HER performance of the Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF electrode was evaluated in 1 M KOH at 25 °C using cathodic polarization and electrochemical impedance spectroscopy (EIS). The Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF electrode exhibited superior HER performance, delivering 58.53 mA cm^− 2 at − 1.4 V with a low overpotential of 210.1 mV at 10 mA cm^− 2. Its high catalytic efficiency was supported by low charge transfer resistance (R_ct), indicating efficient interfacial charge transport. The enhanced double-layer capacitance (C_dl = 4.02 mF cm^− 2) for Zn_0.2Cd_0.2Mn_0.6Fe₂O₄/NF can be attributed to the synergistic effects of multivalent transition metal redox couples and entropy-induced cationic disorder. Complementary structural modeling and Hirshfeld surface analysis further elucidated cation site occupancy and interatomic interactions vital to catalytic stability.

We report the improvement of semiconducting behaviour, dielectric and magnetic property in Mg_0.5Ni_0.5Fe_2−xGd_xO₄ (where x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) synthesized by solid state reaction route. The physical properties have been studied using X-ray diffraction, field effect scanning electron microscopy (FESEM), atomic force microscopy (AFM), UV–Vis spectroscopy, dielectric spectroscopy and magnetic measurement. Rietveld analysis reveals the existence of spinel cubic phase and a secondary phase of GdFeO₃ orthorhombic structure. The Williamson–Hall graph shows the decrease of average crystallite size of spinel phase from 101 to 59 nm due to compressive strain with increasing Gd concentration. The FESEM images exhibited an agglomerate of fine particles due to their magnetic nature. The roughness has been observed in AFM depends on the material, type of dopant, and method of processing. UV spectra analysis shows a decreasing trend of band gap after incorporating Gd³⁺. The dielectric constant shows decreasing trend and dielectric loss shows increasing trend with respect to frequency for all the ferrites. The reflection loss graph indicates the optimal doping with Gd occurs at x = 0.3 for maximum absorption making it a suitable candidate for application like electromagnetic interference shielding or radar absorbing material. The nature of the M-H loop for all the specimens show ferromagnetic behavior. The synthesized samples have modified electrical and magnetic behaviors suitable for microwave applications.

The symmetry breaking in octahedral silsesquioxane and its germanium analogues (Si₈O₁₂H₈ and Ge₈O₁₂H₈) has been investigated using the M06-2X/6-31++G(3df, 3pd) method and group theory. Both structures undergo ({O}_{h}downarrow {T}_{h}) symmetry breaking, characterized by pseudo-Jahn−Teller stabilization energies of 0.22 kcal/mol for Si-POSS and 9.82 kcal/mol for Ge-POSS. Under the influence of the pseudo-Jahn–Teller effect, the distortion vector involves the vibrational a_2g mode with imaginary frequency. The distortion forces in O_h-POSS are predominantly localized on the oxygen atoms and driven by the coupling between the lowest unoccupied molecular orbital (a_1g) and the highest occupied molecular orbital (a_2g). The symmetry breaking is attributed to a pseudo-Jahn–Teller mechanism of type (a_2g x a_1g) = a_2g. The symmetrical substitution of oxygen atoms by X (where X = C, N, P) results in viable T_h-Si₈X₁₂H₈ and T_h-Ge₈X₁₂H₈ structures. The observed pseudo-Jahn–Teller distortion and substitutional symmetry breaking caused by X indicates a consistent electronic relaxation mechanism, characterized by the formation of C=C, N=N and P=P bonds on the POSS cubic faces, which serves as hallmarks of stability. Additionally, we find that the volume of substituted T_h-symmetrical POSS is sufficiently large to accommodate small ions.

Utilizing the spin degree of freedom of electrons to control and store electronic data has become an emerging aspect of advanced spintronic technology. In my present work, I have comprehensively investigated the above room-temperature ferromagnetism and thermoelectric behavior of X₂TiMoO₆ (X = Mg, Ca, Sr, Ba) for a detailed understanding of the field. The formation energy, phonon dispersion spectrum, and tolerance factor have been assessed to determine their thermodynamic, dynamic, and structural stabilities. The optimization analysis explains that ferromagnetic (FM) states liberate more energy than antiferromagnetic (AFM) states, thereby enhancing the stability of the FM states. The Curie temperature and spin polarization are calculated using the Heisenberg model and polarization density, which confirms above-room temperature ferromagnetism. Moreover, the Study investigates various aspects of ferromagnetism, including exchange constants, hybridization, crystal field energy, and exchange energies. The transformation of the magnetic moment from Ti and Mo to the Sr and O sites reveals that the electron spin is mainly responsible for ferromagnetism rather than the cluster of magnetic ions. Furthermore, a comprehensive analysis of transport behavior, including the Seebeck coefficient, electrical & thermal conductivities, and power factor, is executed to see their thermoelectric effects on the spin of electrons and energy harvesting.

This study evaluates two biopolymer-based nanoparticles derived from Giant Reed (cellulose) and chitin as sustainable precursors for dual applications: heavy metal adsorption and liquid crystal formation. The novelty lies in upcycling Giant Reed-based cellulose nanoparticles (Cel-NPs) as metal adsorbents and reusing their metal-chelated forms as effective liquid crystal biopolymers, achieving a zero-waste strategy. The nanoparticles were characterized using Transmission Electron Microscopy (TEM), Attenuated Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray Diffraction (XRD), and Polarized Optical Microscopy (POM) to evaluate their morphology, functional groups, crystallinity, and liquid crystalline behavior. Comparative analysis between Cel-NPs and chitin nanoparticles (Ch-NPs), including their esterified derivatives (ECel-NPs and ECh-NPs), was conducted. Metal chelation studies showed Cel-NPs exhibited higher affinities for Cu²⁺, Zn²⁺, and Cd ²⁺ (29.01 ± 1.1, 30.33 ± 1.2, and 20.69 ± 0.8 mg/g, respectively) compared to Ch-NPs (24.96 ± 0.99, 29.78 ± 1.2, and 17.34 ± 0.7 mg/g). Structural modifications metal loading and esterification with decanoyl chloride enhanced the crystallinity indices of the nanoparticles and significantly improved their liquid crystalline behavior. Notably, the critical concentration for liquid crystal formation dropped from 1 wt% to 0.5 wt% for modified Cel-NPs, and from 5 wt% to 0.5 wt% for modified Ch-NPs, highlighting their potential in advanced biofunctional materials. *Corresponding information: A. H. Basta. email: altaf_halim@yahoo.com, and altaf_basta2004@yahoo.com.

Innovative nanodrug are in high demand for the novel antimicrobial agents development that have Sustained release dosage in gastrointestinal simulation. Therefore, this study looked at the effect of mixing selenium nanoparticles (SeNPs) and their composites with cefepime, embedded in polyvinyl alcohol (PVA) with polyhydroxybutyrate (PHB) matrices for controlled drug release to overcome pathogenic bacteria. These results showed that cefepime (Cef) released more slowly at pH 2 than at pH 7.4. Zero-order, first-order, Higuchi, Hixon–Crowell, and Korsmeyer–Peppas equations were used to study the drug release mechanism at various pH values (2, 7.4). According to zeta potential analysis, the composite exhibited good stability, indicating to strong structure. The nanocomposite possesses an encouraging antimicrobial potential against pathogenic strains S. aureus, E. coli, and P. aeruginosa, Kb. pneumonia strain. Moreover, SeNPs and PHB/PVA/SeNPs/Cef nanocomposites recorded excellent antioxidant activity (87.35% and 79.9%). The total phenolic compounds for SeNPs and PHB/PVA/SeNPs/Cef nanocomposite are 875 mg gallic acid/g and 1160 mg gallic acid/g in 200 µg/mL of SeNPs that activated their antioxidant properties. MTT analysis was showed that PHB/PVA/SeNPs/Cef has no cytotoxic effect on normal HEK- 293 cells and RPE-1 normal cells at even 50 µg/mL of SeNPs for 24 h. Moreover, the coagulation cascade was unaffected by the nanocomposites at the high concentration. Also, there was no evidence of haemolysis when the nanocomposite interacted with the constituents. The release test exhibited controlled drug release of Cef from composite, indicating its potential for use in drug delivery systems.

A modified hydrothermal approach was employed for the synthesis of Pb₃O₄-based, (Pb₃O₄-Co₃O₄ and Pb₃O₄-CuO) nanocomposites. The prepared electrode materials were successfully assessed for their supercapacitor performance and oxygen evolution reaction (OER) activity. The scanning electron microscope (SEM) visualized the formation of uniform, granular and interconnected sheets structures, while transmission electron microscope (TEM) ensured a petal-like structural morphology which enhances the surface area and active site accessibility, that are crucial for increasing electrochemical excellence. Interestingly, the Pb₃O₄-Co₃O₄ and Pb₃O₄-CuO electrodes showed specific capacitances of 867 and 1308 F/g, respectively, along with superior energy densities values of 30.09 and 45.42 Wh/kg. The Pb₃O₄-CuO electrode material showed exceptional cycling performance and retention of 96.03% after excessive cyclic voltammetry cycles. Similarly, Pb₃O₄-CuO also depicted excellent cathodic and anodic b-values of 0.75 and 0.77, respectively. Moreover, the oxygen evolution reaction assessed overpotential value of 315 mV and 182 mV for Pb₃O₄-Co₃O₄ and Pb₃O₄-CuO nanocomposites, respectively. Additionally, the synthesized binary composites demonstrate excellent Tafel slope value of 79 mV/dec and 43 mV/dec for Pb₃O₄/Co₃O₄ and Pb₃O₄/CuO, respectively. Similarly, the electrochemical active surface area (ECSA) of Pb₃O₄/CuO and Pb₃O₄/Co₃O₄ was calculated 606.5 cm² and 368.4 cm², respectively. The Pb₃O₄-CuO nanocomposite showed multifunctional excellence as improved capacitance, energy density, and water splitting systems.

This work explores the green synthesis of ZnO nanoparticles and their subsequent use as the zinc source for constructing Zn-EDTA metal-organic frameworks (MOFs) aimed at efficient CO₂ capture. The objective is to evaluate the adsorption capacity of the resulting MOFs and optimize their structure to enhance carbon sequestration. The Zn-EDTA MOFs were synthesized via a reflux-assisted coordination process using ethylenediaminetetraacetic acid (EDTA) as a ligand. X-ray diffraction (XRD) confirmed the crystalline structure, while Fourier transform infrared spectroscopy (FTIR) identified key functional groups, verifying Zn–EDTA coordination. Nitrogen adsorption–desorption analysis (BET) revealed a surface area of 885 m²/g, a pore volume of 0.41 cm³/g, and an average pore diameter of 8.58 Å, supporting the material’s porosity and gas adsorption potential. CO₂ uptake tests showed a capture capacity of 164.58 mL/g, highlighting the promise of this green-synthesized MOF for sustainable carbon capture applications.

An eco-friendly approach was employed to synthesize pure ZnO and Fe-doped ZnO nanoparticles using Justicia adhatoda leaf extract as a natural reducing and capping agent. X-ray diffraction (XRD) analysis verified the crystalline nature and hexagonal wurtzite phase of the green-synthesized ZnO nanoparticles. UV–Visible spectral analysis demonstrated a band gap narrowing from 3.03 eV for pure ZnO to 2.86 eV for Fe-doped ZnO, indicating enhanced optical behavior as a result of Fe incorporation. Morphological studies using FE-SEM and HRTEM revealed a hexagonal shape with a nanosheet structure, while EDAX confirmed the elemental composition of the nanoparticles. Fourier transform infrared spectroscopy (FTIR) identified the functional groups in the samples, indicating the role of phytochemicals from Justicia adhatoda. X-ray photoelectron spectroscopy (XPS) further confirmed the successful incorporation of Fe²⁺ ions into the Zn²⁺ lattice. Photoluminescence (PL) analysis was performed to assess the emission characteristics, while zeta potential measurements were utilized to determine the surface stability of the nanoparticles. The photocatalytic performance of pure ZnO was noted to be 81% for the degradation of bromophenol blue and 78% for fast green. In contrast, Fe-doped ZnO demonstrated improved efficiencies of 96% and 98% for the degradation of bromophenol blue and fast green, respectively. The Fe–ZnO nanoparticles achieved efficiencies of 96% and 98% in 180 min for bromophenol blue and in 150 min for fast green pollutants. Furthermore, The Fe-doped ZnO nanoparticles demonstrated higher inhibition areas against Staphylococcus aureus (11–18mm), Bacillus subtilis (11–15mm), Penicillium (09–12mm), and Rhizopus (16–17mm) compared to the pure ZnO nanoparticles (Staphylococcus aureus (09–11mm), Bacillus subtilis (01–12mm), Penicillium (08–12mm), and Rhizopus (17–20mm)).These results suggest that the green-synthesized pure ZnO and Fe-doped ZnO nanoparticles have significant potential for photocatalytic and antimicrobial uses.

Graphical Abstract

Fluorescent graphitic carbon nitride quantum dots (g-CNQDs) are an intriguing family of nanostructures that offer a non-toxic, biocompatible, and environmentally friendly alternative, in contrast with traditional semiconductor quantum dots. This review article outlines the recent advances in the synthesis techniques and bioanalytical applications of g-CNQDs. A notable advantage of g-CNQDs is their tunable fluorescence and robust photoluminescence emission, which are attributed to their diminutive size. They can be efficiently synthesised using cost-effective top-down and bottom-up approaches including top-down techniques such as evaporation–condensation, electrochemical modification, chemical oxidation, and solvothermal, hydrothermal, and microwave-assisted processes. Each technique offers distinct advantages that facilitate the production of g-CNQDs with diverse sizes and properties tailored for specific applications. This research highlights important findings about the remarkable photoluminescence characteristics and structural robustness of g-CNQDs, which make them suited for a variety of bioanalytical applications, especially the detection of fluorescent biomolecules. Crucially, g-CNQDs show excellent sensitivity and selectivity in detecting environmental pollutants and biomolecules. The recent advancements in the synthesis techniques and bioanalytical applications of g-CNQDs as fluorescence biosensors have been addressed in this review article. In addition, the challenges and opportunities of g-CNQDs improvement in order to efficiently utilize them in the biological community are also discussed. Apart from providing valuable suggestions for researchers and promoting the progress of zero-dimensional (0D) materials in biotechnology, it also highlights the immense potential to revolutionize bioanalytics and beyond.