Chemical Physics Letters最新文献

The oilfield produced water (PW) treated by traditional process difficult to reduce the chemical oxygen demand COD value to below 50 mg/L. In this work, magnetic nano-Fe₃O₄ modified powdered coconut shell biochar was successfully prepared. The COD value of the PW was reduced from an initial value of 387 mg/L to 37 mg/L in 10 min of low speed mixing using magnetic nano-Fe₃O₄ modified powdered coconut shell biochar. In addition, the spent magnetic nano-Fe₃O₄ modified powdered coconut shell biochar can be regenerated by heating at 240 °C for 20 min. The regenerated magnetic nano-Fe₃O₄ modified powdered coconut shell biochar showed excellent adsorption properties, and the COD value of the PW was reduced to about 35 mg/L in all six recycles.

We developed a machine learning (ML) model to directly predict IR spectra from three-dimensional (3D) molecular structures. The spectra predicted by our model significantly outperform those from density functional theory (DFT) calculations, even after scaling. In a test set of 200 molecules, our model achieves a Spectral Information Similarity Metric (SIS) of 0.92 surpassing the value achieved by DFT scaled frequencies which is 0.57. Additionally, our model considers anharmonic effects offering a fast alternative to laborious anharmonic calculations. Moreover, our model can be used to predict various types of spectra (as UV or NMR) as a function of molecular structure.

In recent years, the search for efficient electrode materials for supercapacitors has focused on improving operating voltage thereby specific energy. This study explores NiCoAl layered double hydroxides (LDHs) as electrode materials, synthesized with varying Ni ratios (x = 0.25, 0.5, 0.75) through a hydrothermal method. The NCAL13 variant demonstrated superior electrochemical performance, achieving a specific capacitance of 1413F/g and retaining 77 % capacitance after 5000 cycles. An asymmetric cell using NCAL13 and activated carbon delivered 150F/g and an energy density of 50.1 Wh/kg, retaining 86 % capacitance after 10,000 cycles, highlighting its potential for supercapacitor applications.

Production of clean energy is an efficient way to solve the environmental pollution. We construct hBNC/Janus MoSTe heterojunction as a photocatalyst for hydrogen production from water splitting. The electronic and optical properties of this heterojunction are investigated by the first-principle. The negative binding energy indicates that the process of this heterojunction is exothermic and it tends to exist stably. The 1.42 eV band gap of this heterojunction is suitable for photocatalyst. The results of PDOS show that the band alignment of hBNC/MoSTe is typical type-II. In addition, the built-in electric field makes the path of photo-generated carries belong to Z-scheme. Therefore, the hBNC/MoSTe is a direct Z-scheme heterojunction and has stronger redox properties. The results of Gibbs free energy indicate that the hydrogen evolution reaction (HER) reaction could complete spontaneously under the reduction overpotential (χ_H2 = 1.38 eV) which is provided by the Photo-generated electrons. The optical coefficient of part visible light is improved compared with monolayer hBNC and MoSTe. Therefore, the h-BNC/MoSTe heterojunction studied here may be a promising candidate for solar-powered Z-scheme photocatalytic water cracking to produce hydrogen, providing a reference for clean energy generation.

Dimeric copper centers are commonly used to activate molecular oxygen in enzymatic and heterogeneous catalysis where Cu₂ is embedded in porous structures. Here we evaluate the ability of recently developed range-separated hybrid van der Waals density functionals to describe activated O₂ in a crystal with the Cu₂O₂ unit and in a

The current study looks into the physical, chemical, and antimicrobial potential of the biogenic Silver Nanoparticles(AgNPs) using Syzygium aromaticum leaf extract.Synthesis parameters were altered to figure out optimum synthesis conditions. Optimum synthesis was observed with 9 mL of 1 mM silver nitrate and 1 mL leaf extract at 55 °C and pH 9 with 24 h incubation.Characterization was performed using UV–vis spectroscopy, X-ray diffraction, Transmission Electron Microscopy, Scanning Electron Microscopy, Fourier Transform Infrared, and Zeta Potential. Average particle size was found to be 37.5 nm. Nanoparticles synthesized exhibited strong antibacterial activity against tested multidrug-resistant pathogens(MDR) pathogens affirming their therapeutic potential.

By measuring X-ray emission of the water molecule in liquid phase we establish a first example of K-shell X-ray emission spectra with strong breakdown of the molecular orbital picture. A complete splitting of the 2a${}_1$ peak into satellites is observed. A theoretical model with electronic configurations generated by coupled excitations/de-excitations, so-called semi-internal configuration interaction, captures the experimentally recorded features well. Differences with respect to the corresponding breakdown effect in ultraviolet photoelectron spectrum are highlighted. Molecular dynamics calculations indicate that solvent broadening can only make up for a small fraction of the width of the recorded 2a${}_1$ derived band.

Among various known positive electrode materials for sodium-ion batteries, polyanion-type cathode materials are the preferred system for high stability and high safety of sodium-ion batteries. Especially, Na₃V₂(PO₄)₃ has enormous development potential. This work uses tea leaves as a novel biomass carbon source to uniformly grow Na₃V₂(PO₄)₃ crystals into a three-dimensional porous carbon framework through a facile sol–gel method. The prepared Na₃V₂(PO₄)₃/C material presents a three-dimensional porous carbon conductive network structure, and its electrochemical performance is significantly improved compared to the pristine material. The Na₃V₂(PO₄)₃/C material exhibits a high initial discharge specific capacity of up to 110.6 mAh g⁻¹ at 0.1 C within 2.0–4.0 V.

Triazole can be used as an effective proton carrier because it has one proton donor and two proton acceptors. Density functional theory calculations were performed to explore the proton transfer mechanism of the triazole molecules in gas and solvents. We employed implicit solvent method to analyze the increase of proton donor–acceptor distance (PDAD) in proton transfer mechanism. The solvents reduce the relative energy in tautomers of 1,2,4-triazole molecules, and their protonated form. Proton transfer occurs only at symmetric pairs in the gas, small PDAD, whereas proton transfer in an asymmetric pair is possible in solvents as the PDAD increases.

Traditional Fenton reactions suffer from slow reaction rates and energy wastage degrade dye contaminant. By constructing a heterojunction interface between quantum dots and titanium dioxide, a CoO@TiO₂ photocatalyst is prepared to extend the photoresponse range to longer wavelengths. Under infrared light irradiation, RhB is degraded by over 97 % after 120 min. CoO@TiO₂ possesses a large surface area, loaded with a substantial amount of quantum dots, forming a p-n heterojunction, significantly enhancing the photocatalytic rate. This study provides a new approach for the efficient preparation of photocatalysts for the degradation of organic dye pollutants.