Journal of Inorganic and Organometallic Polymers and Materials最新文献

The structural, optoelectronic, mechanical, and thermoelectric properties of Na₂SnX₆ (X = I and Br) are analysed using density functional theory (DFT) computations. Cohesive energy, formation energy, and Murnaghan’s equation of state are utilised to confirm structural and thermodynamic stabilities. Elastic constant analysis and structural parameters reveal that the compounds are ductile. The computed direct energy gaps of 3.20 eV (Na₂SnBr₆) and 2.24 eV (Na₂SnI₆) enable absorption of incident electromagnetic radiations in the visible and ultraviolet ranges, making these materials suitable for solar cell and optoelectronic applications. Thermoelectric properties are investigated using the BoltzTraP code based on the semi-classical Boltzmann transport equations (BTE). Electrical and thermal conductivities, Seebeck coefficient, power factor, and figure of merit (ZT) are evaluated as functions of temperature, carrier concentration, and chemical potential. This study identifies Na₂SnX₆ (X = I and Br) as highly promising thermoelectric materials for thermopower generation across a wide temperature range and optoelectronic application.

This study presents a novel approach for developing phosphate-based geopolymeric materials, emphasizing the replacement of conventional casted geopolymeric paste with a compaction technique for a slightly damp geopolymeric powder mixture, eliminating the heating process during elaboration. Three distinct elaboration methods were compared to assess the impact of this new approach. The investigation revealed significant outcomes: geopolymeric materials subjected to compaction exhibited accelerated consolidation within minutes, compared to the few hours required for casted-heated geopolymers. Additionally, the compaction method resulted in improved mechanical strength, achieving three times greater strength in 14 days with a value of 7.2 MPa according to the Brazilian test measurements. These materials also demonstrated exceptional durability, with only a 5% mechanical resistance drop after 24 h of water immersion, and improved dimensional stability compared to conventional casted-based geopolymers. Furthermore, compaction led to materials with reduced open porosity while retaining closed porosity, resulting in a final material with 28% of porosity. The research confirmed the formation of nearly identical geopolymeric materials regardless of the synthesis approach employed. However, the compaction-based method enhanced precursor reactivity and polycondensation kinetics. Sensitivity analyses demonstrated that increasing applied pressure and decreasing compaction speed significantly improved mechanical strength, with optimal values of 60 MPa pressure and 0.2 mm/min compaction speed. Conversely, for casted-based geopolymeric materials, increasing curing temperature to the range of 60–80 °C and extending the heating duration to 1–3 days significantly enhanced mechanical strength. Exceeding these values, however, could abruptly degrade the mechanical properties.

In this work, the electronic structure and optical and thermoelectric properties of HgLu₂(S/Se)₄ spinels were studied using first-principle calculations. From these results, both the compounds are mechanically and energetically stable at cubic phases. Besides this, small band gaps are seen for both the spinels, indicating their deployment in solar cell applications. Along with this, strong optical absorption observed in them makes them useful for solar cell applications. Thermoelectric properties obtained by the BoltzTrap code include the figure of merit, Seebeck coefficient, electrical conductivity, and thermal conductivity. In view of these results, both spinels are promising candidates for thermoelectric applications.

The charge separation efficiency of a photocatalyst plays a pivotal role in the effective removal of organic pollutants from wastewater. In this study, a ternary photocatalyst, BaTiO₃/NiO/g-C₃N₄ (BNG), was developed by depositing g-C₃N₄ (GCN) onto a BaTiO₃/NiO binary system using a simple calcination method to enhance the charge separation and transfer via a dual Z-scheme mechanism. The powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) analyses demonstrated the successful formation of the ternary composite. The photodegradation performance was evaluated using methyl orange (MO) and tetracycline (TC) under UV irradiation. The BNG composite containing 30 wt% GCN (BNG-30) exhibited superior photodegradation efficiencies of 90.8% for MO and 78.2% for TC, which were 5.24 and 1.57 times higher than those pristine BaTiO₃ (BTO), and 3.5 and 1.84 times greater than the binary composite, respectively. The corresponding rate constant for MO and TC were 0.1302 and 0.01507 min^− 1, respectively. The improved photocatalytic performance is attributed to the synergistic interaction within the ternary system, which enhances interfacial charge separation through the dual Z-scheme. Scavenger experiments revealed that superoxides ((:{cdot:text{O}}_{2}^{-})) and hydroxyl radicals ((:cdot:text{O}text{H})) as the dominant reactive species in the photodegradation process. Furthermore, BNG-30 demonstrated excellent stability and recyclability, maintaining its activity over four consecutive cycles. These results highlight the strong potential of BNG ternary photocatalyst for the efficient removal of organic pollutants from wastewater, due to its enhanced charge separation, high degradation efficiency and excellent long-term stability.

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Nonstoichiometric FeMnO_3-δ perovskite nanoparticles was synthesized by sol–gel method. Rietveld refinement of X-ray diffraction (XRD) data revealed that FeMnO_3-δ sample crystallized in cubic bixbyite structure with space group Ia3. The morphological characterizations of this sample were performed by using transmission electron microscopy (TEM), selected area electron diffraction (SAED) pattern, high-resolution TEM (HR-TEM) and Energy dispersive X-ray spectroscopy (EDS) mapping. The N₂ adsorption–desorption isotherm curve of this sample confirmed the existence of micro-mesoporous structure. The presence of Fe²⁺/Fe³⁺, Mn³⁺/Mn⁴⁺ and oxygen vacancies in this sample were confirmed by X-ray photoelectron spectroscopy (XPS) analysis. UV–Vis absorption spectrum revealed that nonstoichiometric FeMnO_3-δ perovskite exhibited semiconductor with direct band gap energy (E_g) of 3.7 eV. The room temperature magnetization hysteresis (M–H) loop revealed that FeMnO_3-δ perovskite exhibited antiferromagnetic behavior with small fraction of weak ferromagnetic. The electrochemical results revealed that the nonstoichiometric FeMnO_3-δ exhibited pseudocapacitive behavior. The obtained results confirmed that FeMnO_3-δ perovskite is considered as a promising supercapacitor electrode.

The ongoing demand for sustainable and efficient electrode material for efficient oxygen evolution reaction (OER) has simulated considerable research in the development of novel electroactive catalysts. This study shows substantial advancement in the utilization of an optimized framework of metal oxides like perovskite-type oxides, combined with reduced graphene oxide (rGO) as an electroactive material for a slower OER process. In this way, we designed a rGO/SrNiO₃ composite as viable and economical electrocatalysts using a sonication technique for enhanced OER activity. The composite electrochemical activity in the context of OER was assessed in a 1.0 M KOH electrolytic solution. Electrochemical outcomes of composite rGO/SrNiO₃ displayed remarkable potential for the OER process by demanding an overpotential (η) of 259 mV at current density (10 mA/cm²). Moreover, the produced nanocomposite demonstrated a minimal Tafel slope (34 mV dec) and lower impedance, illustrating the efficient charge transfer resulting in improved catalytic OER performance. Further, investigation demonstrated that the nanocomposite showed an increased electrochemically active surface area (261.25 cm²) and significant stability for 50 h. The above-stated results indicate that the composite exhibits a high active site density showcasing enhanced charge transfer, improved reaction kinetics and prolonged stability resulting from a synergistic combination of rGO and SrNiO₃.This study investigates how the rGO/SrNiO₃ composite surpasses conventional electrocatalysts, presenting a new approach for efficient and economical catalysts for OER.

A tandem solar cell is designed by combining bandgaps to yield efficient models. Additionally, it utilizes a wider spectrum of solar energy. In this simulation, the full perovskite tandem solar cell (PTSC) reflects a Dion–Jacobson (DJ) 2D layer PeDAMA₂Pb₃I₁₀ absorber with wide bandgap energy (E_g) of 1.88 eV for its top cell and a narrow bandgap halide (NBH) having composition FA_0.7MA_0.3Pb_0.5Sn_0.5I₃ with the numerical value of E_g is 1.22 eV for its bottom cell. Due to the efficient simulation technique of SCAPS-1D for modelling the solar cell characteristics and its parameters, it has been used for the purpose of this study. After which all the parameters are analyzed to achieve optimum level of efficiency of the cell. In this simulation different parameters such as open-circuit voltage (V_oc) is 2.16 V; short-circuit current density (J_sc) is 20.70 mA/cm²; fill factor (FF) is 71.81%; and 32.11% of power conversion efficiency (PCE) in tandem structure is obtained by optimizing both cells due to minimal thermalization and transmission losses which gives better PCE, by carefully altering parameters such as absorber thickness and total defect density for both the cells. Hence, the value of the filtered spectrum and current matching graph values were subsequently analyzed. These prudent studies do the rounds to prove a strong possibility that the perovskite tandem model will increase solar cell efficiency.

The structural, electrical, magnetic, and optical properties of sol-gel-synthesized Cu_0.5Fe_0.5Co₂O₄ spinel cobaltite are investigated in this work. X-ray diffraction (XRD) confirms a phase-pure cubic spinel structure. Electrical characterization reveals semiconducting behavior governed by the Non-overlapping Small Polaron Tunneling (NSPT) model, with conductivity spectra aligning with the Random Barrier Model (RBM). Low activation energies (52 meV from DC conductivity and 41 meV from relaxation time) highlight enhanced charge carrier mobility and superior electrical transport. Dielectric responses are attributed to Maxwell-Wagner interfacial polarization, as supported by impedance spectroscopy, which reveals distinct relaxation dynamics. The temperature dependence of resistance indicates a negative temperature coefficient of resistance (NTCR) in the sample. Magnetic studies demonstrate soft ferrimagnetic behavior, characterized by a low coercive field (132 Oe) and operational frequencies in the microwave range (1.3–1.4 GHz), ideal for high-frequency applications. Optical measurements reveal lower bandgap energies (1.65 eV and 2.25 eV), reduced Urbach energy, a minimal extinction coefficient (~ 10⁻⁵), and notable nonlinear optical parameters, underscoring the material’s potential for optoelectronic devices. Compared to pristine CuCo₂O₄, Fe substitution enhances resistivity, magnetization, and carrier mobility. This indicates that Fe substitution offers an opportunity to improve the functional properties of copper cobaltite.

The distinctive features of Si–O and Si–C bonds make the integration of silicon-organic moieties into organic structures significantly influence the architecture and properties of the resulting hybrid materials often confering conformational flexibility, hydrophobicity, surface activity, self-assembly capacity and dual character (amorphous–crystalline, flexible–rigid, mesomorphic). As a result, silicon-based structural units show considerable potential in the design of functional compounds and materials, relevant for fields such as sensor technology, optoelectronics, catalysis, energy storage and even biomedical applications. In the context of recent advances in the synthesis and functionalization of organosilicon compounds, widely reported in the specialized literature, a series of derivatives have been obtained by chemical coupling of siloxane or silane (as a bridge or tail) moieties with triazole, thiadiazole and other functionalized aromatic moieties. Some of these compounds, but also simpler α,ω-bifunctional disiloxanes, have been investigated as ligands for metal ions, leading to the formation of coordination compounds with different dimensionalities (from 0D to 3D), which can outline a distinct class in coordination chemistry. In this paper, such recently obtained representative organosilicon compounds and their metal-containing derivatives are reviewed, highlighting their defining structural and behavioral features. Although the silicon-based moiety is often perceived as chemically inert in these systems, it plays an essential role in controlling the structural and functional properties of the resulting assemblies.

Microbubbles (MBs) are gaining increased interest in biomedical applications. They are typically in the range of 1–10 μm, composed of a shell made of polymers, lipids, proteins, or surfactant, encapsulating heavy gas such as; sulfur hexafluoride (SF₆), or perfluorocarbons. MBs have a range of medical applications, from ultrasound image enhancement, to drug delivery, and gas delivery. In this study, Chitosan-coated MBs is produced by reacting chitosan and glycerol to produce a shell of crosslinked polymer with SF₆ as the gas core. The population was tested for the presence of Nanobubbles. Moreover, freeze drying has been used to test the capability of the new shell to withstand the freeze-drying conditions. The main point of freeze drying is to allow long term storage of bubbles, facilitate bubble transportation, and change the gas core to oxygen to enhance the benefits of using these MBs. Different characterization techniques have been used, FTIR to confirm that we have developed the hypothesized CS shell for micro/nanobubbles. TEM to test the and image the presence of nanobubbles. The results showed that the produced population included microbubbles and nanobubbles with mean diameter of 3.57 ± 0.71 μm and 55 ± 37 nm respectively. The bubbles have a surface positive charge and high concentration of 1.02 × 10¹² MBs/ml. Moreover, freeze-drying was used to change the gas core to oxygen producing MBs with mean diameter 1 ± 0.7 μm and concentration of 6.5 × 10⁹ MBs/ml. These results indicate the potential of using this new formulation for production of bubbles that can be used for various applications. Further investigation is still in progress for extra optimization and application.