Solid State Sciences最新文献

Supramolecular complexes of 18-crown-6 with isomers of dimethylpyridin-1-ium iodide have been successfully synthesized and characterized using various analytical techniques, including single-crystal X-ray diffraction (SCXRD). SCXRD study revealed the crystal structures of bis(1,2-dimethylpyridin-1-ium iodide)-18-crown-6 (I) with a monoclinic structure in the centric space group P2₁/n, bis(1,3-dimethylpyridin-1-ium iodide)-18-crown-6 (II), and bis(1,4-dimethylpyridin-1-ium iodide)-18-crown-6 (III), both exhibiting triclinic structures in the centric space group Pī. The band gap energies are determined using diffuse reflectance data through the Kubelka-Munk algorithm. The thermal stability of these cocrystals was assessed through differential thermal and thermogravimetric studies, while their surface morphology was analyzed using scanning electron microscopy. The third-order nonlinear optical susceptibilities of cocrystals (I), (II), and (III) were measured at 3.54 × 10⁻⁶ esu, 4.05 × 10⁻⁶ esu, and 4.08 × 10⁻⁶ esu, respectively, indicating their promising utility in nonlinear optical applications.

The crystal and particle size distribution of α-alumina (α-Al₂O₃) nanoparticles is increasingly important for their potential application. However, it is difficult to produce α-Al₂O₃ nanoparticles due to the high activation energy barrier making it difficult to obtain a pure α-Al₂O₃. In this paper, α-Al₂O₃ nanoparticles with an average size of 60 nm in width and about 100–300 nm in length were prepared using isopropanol through thermal treatment at 1200 °C, accompanied by a minor fraction of the θ phase. Addressing the challenge of achieving pure phase α-Al₂O₃, Density Functional Theory (DFT) calculation was conducted to explore the energy landscape similarity between the θ and α crystal phases. The results provided valuable insights into obstacles associated with obtaining pure α-Al₂O₃, enlightening the relationship between surface electronegativity and crystal phases. Furthermore, X-ray Photoelectron Spectroscopy and electrochemical tests were employed to demonstrate that the α phase could enhance the surface electronegativity of Al₂O₃. This comprehensive study not only encompasses the synthesis of Al₂O₃ nanoparticles but also elucidates the distinctions between α and θ phases. These results offer valuable insights into methods optimizing for the synthesis of pure phase α-Al₂O₃.

Calorimetric, dilatometric and pressure studies of (NH₄)₃WO₂F₅ were performed over a wide temperature range, including the Pm-3m ↔ Pa-3 phase transition. Comparison of the obtained results with data for related fluorides (NH₄)₃SnF₇ and (NH₄)₃TiF₇ undergoing the same structural changes showed a significant role of chemical pressure in the formation of thermal and barocaloric properties. A decrease in anomalous entropy in oxyfluoride, ΔS₀ = 12.2 J/mol·K, is accompanied by a significant increase in sensitivity to hydrostatic pressure, dT₀/dp = 93 K/GPa, the preservation of a large change in anomalous deformation δ(ΔV/V)₀ = 0.45 % and a small temperature hysteresis, δT₀ < 1 K. This combination of thermal characteristics has led to both a significant increase in extensive and intensive barocaloric parameters in the low pressures area, and to their high reversibility in the modes of increasing and decreasing pressure.

The article involves the facile bio-synthesis of Manganese (III) Oxide (Mn₃O₄) nanoparticles (NPs) using Curry leaf (Murraya Koenigii) extract as an efficacious chelating agent. The prepared NPs were subjected to various characterization methods such as Powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray (EDX) Analysis, Transmission Electron Microscopy (TEM), Fourier Transform Infrared analysis (FTIR), Ultra Violet spectroscopy study (UV–Vis), Cyclic Voltammetry (CV) and Vibrating Sample Magnetometer (VSM) to study the crystalline structure, morphology, optical properties, electrochemical activity and magnetic property of the sample. The XRD result proved the crystallinity of the sample having crystallite size around 15 nm with tetragonal structure. The absorption band observed at 612 cm⁻¹ indicates the Mn-O stretching modes of tetrahedral sites in FTIR analysis of the prepared sample which confirmed the formation of Mn₃O₄ NPs. Using SEM and TEM techniques, the surface morphology and NPs size were examined. The composition and distribution of the NPs was verified using EDX spectrum and elemental mapping. Using the UV–Visible spectroscopy, the energy band gap (Eg) for the NPs was computed and calculated as 2.34 eV. The Mn₃O₄ NPs evinced a specific capacitance of 276 Fg^-1 at 10 mV/s scan rate. This result proposes that the obtained Mn₃O₄ NPs can be used as a suitable electrode mainly for supercapacitor applications. VSM study revealed the paramagnetic behavior of the synthesized Mn₃O₄ NPs. The synthesized Mn₃O₄ NPs exhibited moderate antibacterial activity with gram positive bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, and gram negative bacteria such as Klebsiella pneumoniae, with the inhibition zones of 12, 10, and 9 mm respectively. Photo catalytic degradation study was carried out for Rhodamine B (RhB) dye, which showed a strong characteristic absorption peak nearly at 554 nm with 94 % of degradation efficiency.

A series of orange-red InGaZnO₄:xEu³⁺ (0.2 mol% ≤ x ≤ 20 mol%) phosphors were successfully synthesized via high-temperature solid-state reaction. The structural characterization, morphology, elemental analysis, and optical properties of the prepared phosphors were extensively discussed. Under 468 nm excitation, the prepared phosphors emit orange-red light at 614 nm and 625 nm due to the electric dipole (ED) transition from the ⁵D₀ to ⁷F₂ level of Eu³⁺. The emission peak at 593 nm is attributed to the magnetic dipole (MD) transition. The optimal doping concentration of Eu³⁺ in the phosphor is 2 mol%, resulting in excellent color purity, with all samples exhibiting purity levels exceeding 99.9 %. Furthermore, the phosphors demonstrate remarkable thermal stability, retaining 73.5 % of their luminescent intensity at 420 K and surpassing a thermal quenching temperature of 480 K. The calculated activation energy (E_a) of InGaZnO₄:2 mol%Eu³⁺ (0.27 eV) further underscores its exceptional thermal stability. The internal quantum efficiency (IQE) of the InGaZnO₄:2 mol%Eu³⁺ phosphor is measured at 46.3 %, indicating a high level of photoelectric conversion efficiency. Latent fingerprints (LFPs) developed using the InGaZnO₄:2 mol%Eu³⁺ phosphor display outstanding selectivity and contrast, allowing for precise identification of Level I-III fingerprint details. Additionally, security ink formulated with InGaZnO₄:2 mol%Eu³⁺ shows potential applications in information encryption and anti-counterfeiting measures. Therefore, the investigated phosphors exhibit significant potential for further development due to their favorable optical properties.

How to prepare adsorbents using economical, environmentally friendly and simple methods has become the focus of research. In this paper, silk cotton (SC) was used as a biomass template impregnated with copper nitrate solution and then calcined to prepare CuO-based adsorbent. Carbon-doped CuO (C/CuO-400) adsorbent was obtained under 400 °C air calcination calcination. It completely replicates the morphology of kapok and consists of uniformly smaller nanoparticles. The effects of different calcination temperatures, adsorption temperatures, adsorption times, adsorbent dosages and different concentrations on the adsorption of lead ions were investigated. The results showed that C/CuO-400 had a good adsorption effect on Pb²⁺, which was suitable for Pseudo second-order and Langmuir, and the maximum adsorption amount of Pb²⁺ was 588.24 mg/g with good Reusability. This environmentally friendly, economical and simple to operate biomass template prepared adsorbent of single tube C/CuO has good adsorption effect on lead ions, which is very meaningful and easy to promote the preparation of adsorbent.

The present research investigated the photodegradation capability of a ternary BiOBr/CuInS₂/WO₃ heterojunction against the tetracycline (TC) antibiotic. BiOBr/CuInS₂/WO₃ heterojunction is formed using a straightforward physical mixing method, whereas pure photocatalysts (CuInS₂, WO₃) were synthesized hydrothermally and BiOBr by a coprecipitation process. The Field Emission Scanning Electron Spectroscopy examination validated the nanorod and nanosheet shape of the fabricated BiOBr-CuInS₂-WO₃. The photodegradation capabilities of the BiOBr-CuInS₂-WO₃ heterojunction were superior to those of other pure photocatalysts, and it followed the S-scheme charge transfer route as indicated by the band alignments. After 120 min of light irradiation, the BiOBr/CuInS₂/WO₃ S-scheme ternary heterojunction obtained a photodegradation rate of 98.9 %, much greater than other pure photocatalysts. According to electron spin resonance investigations and scavenging experiments, the radicals hydroxyl radicals (^•OH), hole (h⁺), superoxide (•O₂⁻) play a significant role in the photodegradation of TC. The ternary heterojunction's improved light absorption, lower recombination rate, and higher photocarrier separation rate were due to the fabrication of S-scheme heterojunction. The ternary BiOBr/CuInS₂/WO₃ photocatalyst's photodegradation efficacy was consequently enhanced. Investigations for photocatalyst reusability demonstrated its exceptional stability, with a 93.8 % degradation rate after five catalytic cycles.

The phase relations in the La₂O₃–Fe₂O₃ system at 1300 °C were studied in the whole concentration range by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The samples were prepared with a concentration step of 1–5 mol %. The isothermal cross-sections of the La₂O₃–Fe₂O₃ phase diagram at 1300 °C are characterized by the presence of three single-phase (A–La₂O₃, LaFeO₃, Fe₂O₃), two two-phase (A–La₂O₃+LaFeO₃, LaFeO₃+Fe₂O₃) regions. The composition corresponding to the perovskite phase is 49 mol % La₂O₃–51 mol % Fe₂O₃. Nanocomposites based on the perovskite phase (LaFeO₃) were obtained by the Pechini method and heterogeneous precipitation from nitrate solutions. Solutions of La³⁺ nitrates, which were obtained by dissolving lanthanum oxide with a content of the main component of 99.99 % in nitric acid. The influence of the production method on the microstructure, morphology, and magnetic properties of nanopowders (LaFeO₃) was studied. According to XRD, infrared spectroscopy, SEM, and TEM, the synthesized perovskite LaFeO₃ is single-phase with a particle size of 50–60 nm. The morphology of powder particles primarily depends on the method of material synthesis. The powder showed ferrimagnetic magnetic properties and had a specific magnetization 0.2 and 0.15 emu/g.