Bulletin of Materials Science最新文献

Vanadium oxides are anticipated to be high-performance energy storage electrodes due to their connected double layer and pseudo-capacitive charge storage mechanism. In the current work, flexible stainless-steel mesh substrates are created using a straightforward hydrothermal approach resulting net-like linked nanoflakes and microflowers. There are more electrochemically active sites for energy storage due to its large surface area. Stainless-steel mesh substrates themselves provide porous structure for charge transfer. Morphological results of SEM show porous nanoflake-like structures grown on the substrate. Phase is confirmed using XRD studies. It shows the specific capacitance of 675.66 F g⁻¹ and 343.33 Wh g⁻¹ of energy density at 0.002 A g⁻¹ current density and power density of 19,000 W g⁻¹.

Metalloid arsenic in its inorganic form features the most toxicity in its mobile form, water. Arsenic in water is a concern and a threat to humanity. The water containing arsenic is aptly termed as ‘devil’s water’. Significant developments have occurred in the past few decades regarding water purification. Researchers have developed various materials to remove arsenic from water. Remediation of arsenic through different technologies (viz. adsorption, precipitation and membrane) has been met. The materials used in these technologies for conducting remediation tasks are identified. The present study covers from activated carbon to polymeric membranes. Hybrid technologies are relevant in this direction. A few field deployments are also covered.

In the present investigation, the distribution of iron ions at octahedral and tetrahedral sites in BaFe₁₂O₁₉ prepared by employing four different synthesis techniques, namely, solid-state reaction, oxalate precursor route, sol–gel and wet chemical methods, have been examined using Mossbauer studies and compared with magnetization data. It was observed that the iron ions distribute in different preferential order at various sites for hexaferrites prepared using different synthesis methods, which is confirmed by Mossbauer spectroscopy. Prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Field emission scanning electron microscopy. Rietveld refinement of all samples revealed an M-type hexagonal structure confirming P63/mmc space group along with a minor peak belonging to the α-Fe₂O₃ phase, except for the sample synthesized by sol–gel route. A uniform spherical shape with a small grain size was observed in sol–gel prepared samples and the Williamson–Hall method was adopted to estimate the average crystallite size, which varies between 72 and 129 nm. The room temperature magnetization studies reveal that the sample synthesized via sol–gel route shows high coercivity and saturation magnetization values due to their smaller grain sizes. Mossbauer spectra of all BaFe₁₂O₁₉ samples were fitted with five sexets assigned to the hexagonal crystal structure of 4f₂, 4f₁, 2a, 12k and 2b sites, where the variation in their relative areas confirms the redistribution of iron ions at these sites.

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Debye–Callaway model in combination with the Murnaghan and Clapeyron equations was used to calculate the hydrostatic pressure effects on lattice thermal conductivity (LTC) of wurtzite gallium nitride. The calculations are for the longitudinal and transverse phonon modes. The results are efficiently fitted with the whole temperature (1–400) of the experimental data. The peak value of LTC declines with the applied pressure from 0 to 14 GPa. This result is due to the decreasing Debye temperature, group velocity and lattice volume. Furthermore, pressure affected the number of dislocations, sample size and Gruneisen parameter (longitudinal and transverse) modes. Consequently, the values of above parameters at zero GPa are (2.5times {10}^{13 }{{text{m}}}^{-2}, 1.8 {text{mm}}), (0.93 ,{text{and}}, 0.52), whilst the values at 14 GPa are (15times {10}^{15}{mathrm{ m}}^{-2}, 1.68 {text{mm}},) (0.818 ,{text{and}}, 0.469), respectively. The results show that hydrostatic pressure does not affect the number of impurities and electron concentrations.

For high dielectric constant, conductive carbide ceramic fillers are scattered in polymer to fabricate composites. However, high conductivity of carbides will lead to high leakage conductance and dielectric loss. In this work, to balance dielectric properties, polymer/ZrC/diamond blends were prepared via complementation of fillers. To perform property comparison, polymer/ZrC blends were prepared. Crystal forms and micromorphology of fillers were confirmed. All blends were measured to obtain dielectric constant, dielectric loss and conductivity at various frequencies. Compared to polymer/ZrC blends, dielectric constant of ternary blends slightly decreases and dielectric loss sharply reduces. By analysing ternary blends, strong interaction at polymer/ZrC interface results in high dielectric constant and insulating diamond results in low-dielectric loss via greatly-decreased leakage conductance. Partner employment of ZrC and diamond is distinctive. Ternary blend loaded with 5 wt% ZrC and 3 wt% diamond exhibits well-balanced dielectric performances (dielectric constant ~ 35.3; dielectric loss ~ 0.48) at 100 Hz. This work will provide valid route for balancing dielectric properties of polymer/conductive carbide blends.

The removal of uranium from radioactive wastewater is an important step in nuclear waste management. In this study, a solid adsorbent was developed utilizing mesoporous alumina encapsulated within polyethersulfone (PES) beads for effective uranium extraction. The encapsulation process enhances the stability and selectivity of the material, while the mesoporous structure of alumina enables controlled mass transfer and optimal uranium adsorption. These composite beads were synthesized and thoroughly characterized, and their performance was evaluated for uranium removal from simulated radioactive wastewater. The synthesized materials have been characterized by FTIR, TGA–DSC, SEM, EDX and BET surface area analysis techniques to get complete insight into morphology, functionality and topography of materials. Batch adsorption experiments revealed rapid uranium uptake, reaching equilibrium within a short time frame. The maximum adsorption capacity was found to be ~18 mg g⁻¹. These findings establish the potential of mesoporous alumina-encapsulated PES beads as a promising candidate for uranium extraction, offering a valuable contribution to the advancement of radioactive waste treatment technologies.

Dyes can be determined as a substance that creates many environmental issues leading to the death of aquatic life, plants and all living organisms. Dye removal can be done by several physical, chemical and biological methods, including the photocatalytic method. Photocatalysis is a method in which light energy is used to degrade the dye. This technique is low-cost and eco-friendly, and it degrades many harmful substances from organic dyes compared to other techniques. The prime aim of the present work is to degrade the largely used organic dyes such as methylene blue, malachite green and crystal violet using EDTA-doped FeZnS₂ and Leishman stain-doped FeZnS₂ thin films. The doped FeZnS₂ thin films were fabricated using the co-precipitation method. Thin fabricated films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and UV–Visible spectroscopy (UV). These characterization studies show an active photo response indicating effective dye degradation. Based on the absorption studies of UV spectroscopy measurements after 60 min, the degradation efficiency of methylene blue, crystal violet and malachite green using EDTA-doped FeZnS₂ are 76, 85 and 90, respectively. Similarly, the degradation efficiency after 60 min of methylene blue, crystal violet and malachite green using Leishman stain-doped FeZnS₂ are 82, 79 and 89, respectively.