Chemical Physics Impact最新文献

Polypyrrole (PPy) was synthesized effectively by chemical oxidative polymerization of pyrrole. Organic-inorganic hybrid materials PPy-TiO₂ with different PPy weight percents were prepared by mechanical mixing, by using titanium oxide nanoparticles. The characterizations of PPy-TiO₂ hybrid nanocomposites were analyzed by FTIR, UV–Vis, XRD, TGA & DSC and SEM & EDAX. Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) were used to distinguish the structure of the attained PPy-TiO₂ hybrid nanocomposites. UV–vis techniques are proved the polymerization of pyrrole monomer and the strong interaction between PPy and TiO₂ nanoparticles. Thermogravimetric analyzer (TGA-DSC) curves revealed that TiO₂ can decrease the weight loss of nanocomposite and increase the thermal stability of synthesized nanocomposites. The residual mass of the pure Pyy-36.51 %, PPy-TiO₂ (25 %)-64.82 %, PPy-TiO₂ (50 %)-60.82 %, PPy-TiO₂ (75 %)-70.50 % and pure TiO₂- 96.69 % nanocomposites at the residual temperature 497.80 °C. The morphology and molecular structure of the hybrid nanocomposite were characterized by scanning electron microscope & Energy dispersive X-ray analysis spectroscopy (SEM & EDAX). These characterization results confirmed the polymerization of pyrrole and the strong interaction between PPy and TiO₂. The material with outstanding absorption capability that meet in optical application is the challenging way, thus the photocatalytic analysis of PPy-TiO₂ hybrid nanocomposites is merely a admissible results. It is notably the favorable degradation efficiency of pure PPy, the PPy+TiO₂ (25 % 50 % & 75 %) nanocomposites are 82 %, 66 %, 67 % and 53 % respectively.

In this communication, for the first of its kind, CuAl2O4 doped with Ce³⁺ (1-9 mol %) are syn- thesized by solution combustion method using Aloe Vera gel as a reducing agent. The as-formed sample was calcined at 500° C for 3 hours, followed by characterization. The addition of dopants to the copper aluminate matrix didn't alter the crystal structure of the host matrix. Bragg reflec- tions confirm the formation of the cubic phase and also absence of other impurities. The surface morphology consists of nanorods arranged one above the other. The estimated crystallite size was found to decrease from 12 to 9 nm whereas, the direct energy band gap increases from 2.84 to 3.02 eV with an increase in dopant concentration. Under λex = 305 nm excitation, photoluminescence (PL) emission spectra have a high intense peak at 553 nm along with a less intense peak at 472 nm. The peak at 553 nm can be attributed to the existence of oxygen vacancies which arise due to the transition of an electron from the ²D_3/2 → ²F_7/2 of Ce³⁺, however, the peak observed at 472 nm results from the transition of ionized oxygen vacancies (VO) to the valence band caused by the ²D_3/2 → ²F_5/2 transition. The CIE coordinates lie well within the green region with 5758 K aver- age CCT. Further, Cyclic voltammetry analysis was conducted to investigate oxidation and redox peaks, while electrochemical impedance spectroscopy provided insights into ion transport kinetics. Specific capacitance values ranging from 29 to 59 F/g were obtained for CuAl₂O₄:Ce(1-9 mol %) NPs. These findings suggest potential applications for the synthesized material in areas such as display technology as a green nano phosphor and energy storage materials.

Calcium ferrite nanoparticles doped with Chromium (10-50 mol %) are synthesized using the solution combustion method, employing citrus Lemon extract as a reducing agent, followed by a calcination process at 500${}^o$C. Various characterization techniques are employed on the calcined samples. The Bragg reflections resulting from Chromium doping confirm the formation of a singular orthorhombic calcium ferrite phase. Crystallite sizes determined using both Scherrer’s and W-H plot methods found to be decreases with increase in dopant concentration. The surface morphology showcases agglomerated nanoparticles with irregular shapes and sizes, accompanied by pores and voids. The energy band gap found to be increases with increase in dopant concentration from 2.82 to 2.93 eV. The hysteresis loop analysis provides magnetic parameters including saturation magnetization (M${}_s$), remanence (M${}_r$), and coercivity (H${}_c$). As the dopant concentration increases, M${}_s$ and H${}_c$ found to be maximum at 30 mol% cr${}^{3+}$ concentration in CaFe${}_2$O${}_4$ NPs. Linear increase in frequency-dependent conductivity at lower frequencies was observed. The presence of semicircles at low frequencies signifies compliance with the Cole-Cole formula for impedance behavior. Additionally, a detailed discussion on dielectric properties is presented. Notably, the dielectric constant decreases from 4.2 to 2.74 with an increase in dopant concentration. These distinctive attributes position the samples as suitable candidates for memory devices as well as high-frequency device applications.

Dye-sensitized solar cells (DSSCs) offer a promising, cost-effective alternative to conventional photovoltaic systems. Organic sensitizers, capable of capturing a broad spectrum of sunlight, are key components in DSSCs, but their development and testing are often time-consuming and expensive. Quantum chemical calculations, specifically Density Functional Theory (DFT), have emerged as valuable tools to evaluate potential dye candidates, streamlining the design process and reducing costs. This study investigated the molecular structures and photophysical properties of three common dye classes used in high-performance DSSCs: natural pigments, anthocyanidin pigments, and squaraine dyes. Employing DFT and time-dependent DFT (TD-DFT) at the B3LYP/6–31G level, key parameters such as the HOMO-LUMO energy gap, free energy differences for electron injection and dye regeneration, short-circuit current density, total reorganization energy, and open-circuit voltage were analyzed. Additionally, maximum absorption wavelengths and oscillator strength values were calculated. Our findings provide valuable insights into the optical and electrical properties of these natural dyes, aiding DSSC manufacturers in selecting optimal sensitizers. This research highlights the potential of computational methods in accelerating dye development and improving the overall efficiency of DSSC technology.

Using Co-precipitation method, an attempt was made to prepare lithium ferrite. However, during the synthesis, formation of an additional α-Fe₂O₃ phase along with Li_0.5Fe_2.5O₄ was observed. To reduce the α-Fe₂O₃ phase, samples were annealed at 700°C, 800°C and 900°C temperatures for 2 hours. The investigated samples were then characterized using X-Ray diffraction for phase formation and Rietveld analysis was carried out to determine the different structural parameters such as phase percentage, lattice parameter and cell volume. The Chi square values were observed to be within the limit along with goodness of fit less than 3 for all the samples annealed at different temperatures. Surface morphology was carried out using scanning electron microscope and the average grain size was found to be 1.43 µm for the sample annealed at 900°C. Magnetic properties of samples were investigated, and it was observed that all the samples exhibit low values of saturation magnetization along with coercivity. The presence of two phases such as α-Fe₂O₃ phase and lithium ferrite phase dilutes the exchange interaction, tuning the magnetic parameters.

A series of Na₄Ca (PO₃)₆: xmol% Eu³⁺ (x = 1, 2, 3, 4 and 5) was synthesized using a solid-state method and characterized using various techniques. The X-ray powder diffraction data confirmed that the phosphors crystalized in the monoclinic phase. The Fourier-transform infrared spectroscopy confirmed the presence of phosphate groups and an HO-H peak. The optical bandgaps got smaller as the Eu³⁺ concentration went up as seen in the diffuse reflectance data. The photoluminescence excitation spectra obtained when monitoring the 613 nm emission line showed peaks assigned to 4f→4f Eu³⁺ transitions. When the excitation was monitored at 394 nm, the emission exhibited strong narrow bands at 591, 613, 651 and 698 nm owing to the ⁵D₀ → ⁷F_{J (J = 0 - 4)} transitions of Eu³⁺. The main emission peak increased with Eu³⁺ concentration from 1 mol% to 4 mol% and decreased significantly as the Eu³⁺ concentration reached 5 mol%. The concentration quenching effect is responsible for the drop in PL intensity at concentrations higher than the optimum Eu³⁺ concentration. The International Commission on Illumination (CIE) chromaticity coordinates of the phosphors displayed colour response in the orange- red region, suggesting that they have potential application in the orange-red colour-emitting light displays.

It has been established that three-component condensation of benzaldehyde, acetone and urea catalyzed H₂SO₄ leads to the formation of spirobi[hexahidropyrimidine]-dione derivatives. The structure of the synthesized compound has been proved by X-ray method. The results of the quantum theory of atom-in-molecule and noncovalent interaction index analysis showed no intramolecular hydrogen bonds in the molecule studied. However, it contains four NH bonds and two CO groups. Based on the result of the DFT-NBO analysis, it was the lone pairs of oxygen on the CO group which are forming strong orbital interactions with the antibonding orbital of the CN single bond. The molecular docking was performed to investigate potential binding interactions of the compound with four target proteins including 5I4T (HIV-1), 5R7Z, 6M71 and 6VYB (SARS-Cov-2). Additionally, in-silico drug-likeness and ADME studies suggested oral activity (violations ≤ 1) of scaffold and predicted to be actively effluxed by P-gp (PGP+).

This study presents a comprehensive investigation into the molecular dynamics of solvation environments through an integrated approach combining Fourier-transform infrared (FTIR) spectroscopy, molecular dynamics (MD) simulations, and two-dimensional infrared (2D IR) spectroscopy. We explore the solvation of an ionic solute (ammonium thiocyanate) in various solvent systems, including N,N-dimethylformamide (DMF), water, and a 0.5 mole fraction of DMF in water, aiming to unravel the intricate interplay between solute-solvent interactions and solvent dynamics across diverse solvation environments. By integrating FTIR spectral analysis with radial distribution functions and coordination numbers obtained from MD simulations, we decipher the solvent composition around the solute molecule. Analysis of 2D IR spectra and hydrogen bond, as well as dipolar autocorrelation function from MD simulations, further elucidates the nuances of solute-solvent interactions, highlighting the impact of solvent dynamics on solvation structures. Our results reveal a significant slowdown of the solvent structural dynamics in the equimolar binary solvent mixture compared to the neat solvents. This slowdown underscores the complex relationship between solute-solvent interactions and solvent dynamics. The integration of FTIR, MD simulations, and 2D IR spectroscopy provides a unified framework for obtaining a holistic understanding of solvation dynamics, offering valuable insights into the underlying molecular mechanisms governing solute-solvent interactions in complex systems. These results pave the way for future studies to delve deeper into the molecular intricacies of solvation phenomena.

Fe${}_2$O${}_3$: Ni (1–9 mol.%) nanoparticles (NPs) were synthesized using the co-precipitation method and calcined at $500{}^{\circ }$C for 12 h. The crystallite size, phase, crystallinity, and structural parameters were analyzed via powder X-ray diffraction. The Bragg reflections confirmed that the synthesized NPs crystallize in a pure hexagonal crystal structure with space group R-3c. Surface morphology analysis revealed agglomerated NPs of irregular sizes and shapes. Energy Dispersive X-ray Analysis confirmed the presence of Fe, O, and Ni elements, as well as the purity of the sample. Both the direct band gap energy and crystallite size decreased with increasing dopant concentration. Detailed studies were conducted on the photoluminescence and anticancer properties. The CIE coordinates indicated a color tuning from blue to green in the visible region. CIE coordinates and CCT values ranging between 2860 to 9547 k demonstrated that the synthesized nanophosphor material meets the requirements of display technology. Additionally, anticancer properties were investigated using HeLa cells and compared with the standard drug cisplatin for biomedical applications. Electrochemical investigations revealed super capacitance values ranging from 93.43 to 149.13 F/g at a scan rate of 10 mV/s with increasing Ni${}^{2+}$ concentration. Therefore, the synthesized Ni${}^{2+}$-doped hematite NPs show great promise in display technology, the biomedical field, and as supercapacitors in energy storage devices.

This study focuses on the synthesis of SrVO₃ through the reduction of Sr₂V₂O₇ by annealing in a reducing atmosphere. The effects of annealing temperature and annealing duration on Sr₂V₂O₇ were investigated. The X-ray powder diffraction pattern showed that stoichiometric changes to Sr₂V₂O₇ were achieved only at an elevated annealing temperature of 1000 °C in a reducing atmosphere, and that the desired SrVO₃ was obtained only after 144 h of annealing. Further investigation of SrVO₃ was performed using X-ray photoelectron spectroscopy, which confirmed that the reduction of V⁵⁺ found in Sr₂V₂O₇ to V⁴⁺ found in SrVO₃ was achieved.