Chemical Physics Impact最新文献

Doping is a promising route to improve photodegradation performance of wide bandgap semiconductors and has drawn attention for the fabrication of efficient sun light driven photocatalysts. We have reported a simple wet chemical fabrication of Pr doped ZnO nanorods with strong photodegradation efficiency in the decolorization of organic pollutants such as synthetic dyes and antibiotic levofloxacin. The influence of Pr doping on the structure, lattice parameters and morphology of nanostructured ZnO were investigated via XRD, Raman spectroscopy and FESEM, while PL and UV–visible spectroscopy were employed to study the optical absorption and photocatalytic response. The results revealed that Pr⁺³ ions are successfully substituted in ZnO lattice and band gap of the doped ZnO photocatalysts shifted slightly to the visible region. Photocatalytic capability of ZnO nanostructures was significantly improved upon Pr doping and amongst all 0.5 % Pr doped ZnO nanorods exhibited superior photodegradation ability under sunlight illumination. The enhanced photodegradation performance is attributed to improved light utilization, high defect concentration and effective separation of photoinduced charge carriers. The degradation mechanism along with the scavenger trapping experiments has been proposed which showed that hydroxyl radicals are the dominating active species involved in the decomposition of pollutant.

In the present work, a novel coordination polymer {[Cu(phen)(Tmdipy)(NO₃)H₂O](NO₃) 2.5(H₂O)}_n (phen = 1,10-phenanthroline, Tmdipy = 4,4′- Trimethylenedipyridine), has been prepared and structurally determined by elemental analysis, IR, EPR, UV–visible and single-crystal X-ray crystallography. The complex crystallized in triclinic space group P -1, and the copper(II) shows a distorted octahedral geometry, with Jahn-Teller distortion occurring in the (4 + 2) CuN₄O₂ coordination sphere. The crystal structure evidences that the CP1 is formed of dinuclear [Cu(phen)(Tmdipy)(NO₃)(H₂O)]₂ units weakly connected by nitrate anions giving rise to 1D polymeric chain structure. EPR measurement confirms about the distorted octahedral geometry of the complex. By using UV–Vis absorption, fluorescence spectroscopy, and cyclic voltammetric techniques, the binding studies of copper(II) complex with calf thymus DNA (CT-DNA) were investigated. Additionally, the gel electrophoresis method was used to examine the cleavage of pBR322 DNA by copper(II) complex and exhibited potent cytotoxic effects against human cell line (HepG2). Finally, magnetic properties, molecular docking studies and photoluminescence characteristics have been evaluated.

The Nickel Tungstate nanomaterial was synthesized by the green synthesis method. The powder x-ray diffraction analysis was carried out for Nickel Tungstate and its crystalline nature was identified. The optical properties of the Nickel Tungstate were studied. The surface morphology of the Nickel Tungstate was tested using a scanning electron microscope (SEM). The surface area analysis was obtained by BET analysis. X-ray photoelectron Spectroscopy was used to identify the Binding energy of the materials. The electrochemical properties were investigated using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and Charge-Discharge (GCD). The highest cyclic stability for 10,000 charge and discharge cycle was reported in this paper with good retention at 98 %. NiWO₄ NPs electrode material shows high specific capacitance values of 425 F g⁻¹, 300 F g⁻¹ and 605 F g⁻¹ at a current density of 3 mA/g for pH5, pH6 and pH7 respectively.

Protein-based biomaterials such as thin films have an edge over synthetic and bio-based polymers, due to their biodegradability in addition to other interesting properties. Proteins can be utilized to create such materials with specific functional characteristics. We report the preparation of transparent human serum albumin thin films in presence of CTAB-capped gold nanorods with different compositions of protein as well as the plasticizer i.e., sorbitol. The mechanical properties, surface topology, morphology, molecular structure, moisture content, total soluble material, biodegradability, antibacterial activity and optical properties have been investigated. Gold nanorods act as crosslinkers and sorbitol as a plasticizer increases plasticity and hardness of the films. The films deposited are biodegradable, water soluble and flexible in nature. AFM images reveal a pattern on the surface with different average heights with an increase in surface roughness with the addition of sorbitol. NINT studies show increased hardness and elastic modulus with the same amount of sorbitol but higher amounts of protein. Fourier Transform Infrared spectroscopy studies indicate the change in molecular structure of the films, in terms of a change in the hydrogen bonding network that impacts the water content and hardness of the films. Most importantly the films show antibacterial property, modulated by the composition used. The interesting features and the enhanced mechanical properties pave the path for potential applications of the films. The study shows that the optimization of the composition is crucial to achieve the desired film material with required properties.

The first aim of this work was a systematic experimental and theoretical study of the basal-spacing and characteristics of X-rays diffraction-peaks (positions, intensities, crystallites size...), versus the polymer-density, for a natural bentonite-poly(ethylene glycol) composite. The natural bentonite was extracted from a deposit located in Eastern Rif chain of Morocco (near Nador-city). The basal distance and diffraction-peaks characteristics were measured using X-Rays Diffraction (XRD) method, first, for raw bentonite, and second, for bentonite-poly(ethylene glycol) composites. In particular, measurements reveal the existence of a series of montmorillonite-phases (crystallites) of different sizes within the composites. Afterwards, we have developed a powerful theoretical approach based on Renormalization Theory, and obtain exact scaling relations for the physical quantities of interest. We have compared our theoretical predictions with our experimental data dealt with the considered natural bentonite-poly(ethylene glycol) composites, and found that theory and experiment are in good agreement. Also, as a complementary experimental study, we achieved a detailed analysis of pure PEG, natural bentonite and Bentonite-PEG composites using the so-called Fourier Transform Infrared Spectroscopy (FTIR) tool. A comparison between these complexes show that the polymer-density affects drastically the stretching and bending vibration modes.

Interfacial solar steam generation is considered as economical and more effective implementation of Solar steam generation (SSG) where solar energy is concentrated at the liquid surface via the utilization of heat localization materials (HLM). Herein we report the fabrication of an HLM constituted of a nanocomposite absorber of graphitic carbon nitride (g-C₃N₄) and covellite copper sulfide (CuS) supported on a mixed cellulose ester membrane, with a substrate of air laid paper-wrapped polystyrene foam. This structure allowed for strong broad-spectrum absorbance, increased hydrophilic character and minimal thermal losses. The HLM system absorbed 98% of the material and had an evaporation rate of 2.58 kgs per square meter per hour. This is twice the evaporation rate of water tested under the same conditions. Moreover, as fabricated HLM was also incorporated in a solar still in order to assess its practical performance in solar distillation. Initial studies proved that HLM modified solar still was more effective than conventional solar stills.

One of the most promising bimetallic sulphides for use in energy-storage systems is NiCo₂S₄, but further research is required to give it a high reversibility and electrochemical reaction capacity. In this study, we show the rational materials design of an ideal NiCo₂S₄ nanoparticle as a NiCo₂S₄/RGO nanocomposite, embedded in a reduced graphene oxide (RGO) matrix. NiCo₂S₄ nanoparticles, which ranged in size from 20 to 25 nm and were firmly fixed on the surface of RGO sheets, made up the produced composite. As predicted, the produced nanocomposite displayed a high specific surface area, a mesoporous structure, and high conductivity, resulting in a large electroactive area and rapid electron and ion motion. Additionally, we present the advancements in material science, showcasing the NiCo₂S₄/RGO nanocomposite electrode, which has a long cycle life of 5000 cycles, a high capacitance retention of 85.6 %, and an exceptional specific capacitance of 1505 Fg^-1 at 1 Ag^-1. A high active-material loading asymmetric supercapacitor serves as an example of the real-world use. The NiCo₂S₄/RGO nanocomposite exhibits an exceptional 48 Whkg^-1 energy density at a power density of 985 Whkg^-1, while maintaining a high power density of 7227 Wkg^-1 density of 25 Whkg^-1. The exceptional stability and electrochemical efficiency of the NiCo₂S₄/RGO nanocomposite validate that our methodical materials science and technology optimisation in the areas of active substance synthesis, electrode expansion, and device design/fabrication will help advance the development of high-performance supercapacitors in future years.

Bimetallic nanostructures can exhibit significant broadening of Mie resonances compared to monometallic nanoparticles. Here, we study these materials using Electron Energy Loss Spectroscopy at a single particle level. This technique is immensely effective to probe direct structure-property correlation of nanoparticles. We are thus able to confirm the broadening of Mie resonances at a single particle level. This effect is analyzed in the context of emergence of a new dielectric constant that originates from metallic interfaces. We employ Coronado-Schatz corrections to the usual dielectric constants of the constituent metals to quantitatively simulate these materials. The resultant materials thus exhibit optical cross-sections that are 38.5 % and 4.2 % of the gold and silver nanoparticle optical cross-section at 2.5 eV and 3.45 eV, respectively. A strong agreement between theory and experiment is observed. We also confirmed the effectiveness of our approach for nanoparticles with different morphologies as well as different compositional ratios. Our study suggests an effective strategy to regulate the dielectric properties of bimetallic nanostructures through interface engineering.

Coldeniaprocumbens leaf extract assisted green synthesis of gadolinium-doped bismuth oxide nanoparticles (Gd-Bi₂O₃NPs) was demonstrated. Electron microscopic analysis indicated that the Gd-Bi₂O₃ has nanoflake-like shape with a narrow size distribution of 20–30 nm. FT-IR and XRD analysis confirmed the doping of Gd-ions into Bi₂O₃ crystal structure. The UV–vis spectral investigation was carried to know the characteristic absorbance peaks and the band gap of Gd-Bi₂O₃ samples. The antibacterial activity of Gd-Bi₂O₃ samples was evaluated against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Enterococcus faecalis. The larvicidal activity of Gd-Bi₂O₃ samples was also evaluated against the mosquito larvae of Aedesaegypti and Aedesalbopictus. Furthermore, the photocatalytic potential of Gd-Bi₂O₃ samples has been evaluated using malachite green (MG) and methylene blue (MB) dyes under visible light radiation. The green Gd-Bi₂O₃ samples displayed potent antibacterial, larvicidal, and photocatalytic activities, making them a promising candidate for environmental remediation applications.

Aluminium-doped magnesium ferrite (MAFO) has garnered significant interest due to its recently observed low microwave loss properties, making it invaluable for applications at high-frequency operations, including fields like spintronics and magnonics. This study delves into the optical and dielectric properties of MgAl_0.5Fe_1.5O₄ synthesized via a conventional solid-state method followed by sintering at 1350 °C for 6 hrs. The X-ray diffraction analysis confirmed the formation of pure, single-phase MAFO spinel ferrite with the lattice constant of 8.313 Å. The Williamson–Hall (W-H) method was employed to determine the crystallite size and strain from X-ray diffraction data, resulting in values of 115.4 nm and 9.37 × 10^–4, respectively. UV–visible spectroscopy was used to determine the optical properties, revealing a band gap of 2.38 eV and an average refractive index of 2.09 for the investigated spinel ferrite. The dielectric properties including capacitance, dielectric constant (ε), dielectric loss, ac conductivity, complex impedance, and modulus of MAFO sample were studied as a function of frequency for various temperatures. This comprehensive analysis sheds light on the previously undiscovered traits in the material's transport phenomena and optical attributes, opening an exciting and active field of research into its other physical properties.