Chemical Physics Letters最新文献

This study reports a green-mediated fabrication of NiO nanoparticles (NiO NPs) using Parmelia Perlata lichen extract as a sustainable source. The Physical, chemical, optical, and morphological behavior of the fabricated NiO NPs were analyzed by employing diverse analytical profiles like XRD, FTIR, UV, and SEM. FTIR spectrum demonstrates the involvement of various phytochemicals in the bio-fabrication of NiO NPs. Furthermore, the appearance of a band at 668 cm⁻¹ indicates the successful formation of NiO NPs. The observations of the SEM analysis depicted that the average particle size was in the range of 40–50 nm. The result of the antibacterial study indicates that the NiO NPs significantly reduce the growth of Staphylococcus aureus (19 mm). The result of the photocatalytic research illustrated that the bio-fabricated NiO NPs exhibited superior photocatalytic activity in the degradation of acridine orange dye achieving 84 % degradation efficiency.

The effect of atomic electronegativity on the excited state intramolecular proton transfer (ESIPT) and photophysical properties of naphthalene derivatives containing DNHP, DPHP and DAHP have been researched through the density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. The potential energy curve (PEC) calculated shows that DNHP, DPHP and DAHP can generate ESIPT process and the ESIPT rate increases with the decrease of atomic electronegativity. Subsequently, we further explain the influence of atomic electronegativity on the ESIPT mechanism and photophysical properties of these molecules by electron-hole analysis. Eventually, we sincerely hope that these studies can be helpful in their application.

In the context of carbon peaking and carbon neutrality goals, dry reforming of methane (DRM) offers both environmental and economic benefits and holds great promise for development. In this work, based on Ni loaded MgO, two structural models constructed by transition metal loading (TM+Ni − MgO, TM=Fe, Zr, Mo) and doping (Ni − TM/MgO) were used for DRM by density functional theory (DFT). And the adsorption of CO₂ and CH₄ on these structures was analyzed. The partial density of states (PDOS) and charge density difference (CDD) indicate that due to the presence of unfilled electron d − orbitals in the TM atoms, electron transfer occurs between them and the p − orbitals of the C and O atoms. It facilitates the interactions and enhances the adsorption between CO₂ and MgO. On this basis, the DRM reactions on Fe and Ni loaded MgO (FeNi − MgO) and Ni − loaded, Fe − doped MgO (Ni − Fe/MgO) were screened for focused research. It was revealed that the addition of Fe lowered the energy barrier values for some of the elementary reaction steps, allowing the reaction to proceed more easily. And Ni − Fe/MgO showed greater advantages by possessing more stable energy barrier fluctuation intervals (ER1 − ER3) and the smallest CO₂ dissociation energy barrier.

We report the preparation of multi-walled carbon nanotubes (MWCNTs) by using a simple and cost-effective method for supercapacitor applications. The fabricated MWCNTs electrode shows a maximum specific capacitance of 278 F g⁻¹ at 1 A g⁻¹ and 257 F g⁻¹ at 5 mV/s. Also, excellent retention has been achieved in the fabricated MWCNT electrode and 97 % capacitance is retained even after 10,000 cycles. The findings highlight the potential of pyrolysis-synthesized MWCNTs as a viable electrode material for supercapacitors, offering a pathway towards the development of efficient and durable energy storage devices for various applications.

Five resonant states of long-lived negative molecular ions were defined during the gas-phase resonant electron capture by perylene. Three states are the ground state (0.05  eV) and two shape resonances (0.4  eV and 0.7  eV). Core-excited Feshbach resonance (1.4  eV) transits into a quartet state, which delays the autodetachment of additional electron and causes the negative differential conductance in tunneling transition due to the spin prohibition. Inter-shell resonance (2.5  eV) is mixed with the ground state with the same symmetry and is likely to be stabilized through the light emission with simultaneous transition to a quartet state.

As one of the gaseous signaling molecules in biological systems, hydrogen sulfide(H₂S) is involved in numerous physiological processes and diseases. Therefore, rapid, effective, and real-time detection of H₂S is of great importance. Based on its excellent optical properties, dicyanoisophorone has attracted much attention in recent years, and a large number of corresponding probes have been developed to detect H₂S in biological systems. In this paper, the fluorescence mechanisms of three dicyanoisophorone-based fluorescent probes are investigated and the near-infrared (NIR) fluorescence attribution of the products is discussed by density-functional theory and time-dependent density-functional theory methods. Frontier molecular orbital analysis shows that the non-fluorescence of the probes is attributed to the photo-induced electron transfer process. Structural change and reduced density gradient analyses indicate that the position of the hydroxyl group and the deprotonation have a non-negligible influence on the interactions within the products. The five- or six-membered ring-like structures formed by interactions make the molecule stain as a planar and the fluorescence emission, while the twist exists the fluorescence quenching. In addition, spectral information shows that the emission of NIR fluorescence originates from the deprotonated form of the product.

The heavy metal Pb(II) is highly toxic, and it is very important for its separation and collection to improve water quality. To alleviate the phenomenon of agglomeration and inactivation, the highly dispersible composite materials (CoFe₂O₄-CMC) were prepared by modifying super-paramagnetic CoFe₂O₄ using carboxymethyl cellulose (CMC) in this paper. The adsorption capacity of CoFe₂O₄-CMC0.5 for Pb(II) was 119.3 mg/g. Dynamic fitting results showed that the adsorption process included physical adsorption of intermolecular force and chemical adsorption of coordination; The results of thermodynamic study showed that the adsorption process was endothermic. Compared with CoFe₂O₄, the addition of CMC improved the dispersibility and adsorption performance, providing a new idea for environmental water quality remediation.

In this work, Cu_1.04Mn_0.96O₂ nanosheets were synthesized via a simple hydrothermal method, and their electrochemical lithium storage properties and reaction mechanisms were investigated. The nanosheet structure effectively promotes electron transfer and shortens the transport path. Additionally, the partial substitution of Cu for Mn decreases the Jahn-Teller distortion of the MnO₆ octahedron. Employing as an anode for Li-ion batteries, the specific capacity reached 610.91 mAh g⁻¹ after 100 cycles at a current density of 100 mA g⁻¹.

Excellent thermal stability and tunable optoelectronic features are two unique characteristics of ternary chalcogenides. The first −principles investigations were carried out to look into the intricate interactions between the optical, thermoelectric, and electronic features of novel ternary chalcogenides. The stability of these studied materials was confirmed by the computed formation energy values. There is a strong correlation between the formation energy and the ionicity of W-X bonds, indicating that materials with lower formation energy are connected to a higher number of ionic bonds. The valence band maximum and conduction band minimum of both WSeS and WSeTe materials are located at the Γ-point, which confirms they are direct band gap semiconductors. The heavier element Te is incorporated, making the electronic structure of WSeTe more complex than that of WSeS. The ε₁(ω) was negative at higher photon energy, which is associated with these materials’ response being closer to that of a metallic in the specified energy range. WSeS and WSeTe exhibit peaks in ε₂(ω) representing the highest densities of electronic states that can take part in optical transitions. As fewer states become accessible for the high-energy transitions that make these materials ideal for use in optoelectronics and photovoltaics, as confirmed by the n(ω) decreases as a result of a drop in absorption. The behavior of charge carriers and their interactions with the lattices leads to an almost linear increase in electrical thermal conductivity with temperature. Because electron–phonon scattering, the main type of scattering, increases with temperature, electrical conductivity in these materials often decreases as temperature rises.

Fe-based Prussian blue (FePB) has been widely studied as cathode materials of potassium ion batteries due to its three-dimensional open framework structure and large ion migration channels. In this study, the effect of the introduction of various metals (Co²⁺, Cu²⁺, Ni²⁺, Mn²⁺) on the rate and cycle properties of FePB was investigated. MnCoNiFePB cathode material shows better electrochemical performance, with the initial discharge capacity of 91.3 and 75.4 mAh g⁻¹ (capacity retention is 56.7 % after 100 cycles) at 0.2C and 1C, respectively. These results inspire new ideas for the development and application of potassium ion battery electrode materials.