Chemical Physics最新文献

Ester-functionalized ionic liquids (ILs) are widely applied in electrochemistry, separation, reduction and extraction, but there are few basic researches on them. This study investigates the hydrogen bonding interactions between the ester-functionalized ILs and dimethyl sulfoxide (DMSO), as well as compares it to the ethyl acetate–DMSO (CH₃COOCH₂CH₃–DMSO) system. Experimental and quantum chemical calculation sections were employed for this purpose. The results demonstrate that: (1) The hydrogen bonding interactions in the 1-acetoxymethyl-3-methylimidazolium tetrafluoroborate (AOMMIMBF₄–DMSO) and 1-acetoxyethyl-3-methylimidazolium tetrafluoroborate (AOEMIMBF₄–DMSO) systems are stronger than that in CH₃COOCH₂CH₃–DMSO system. (2) AOMMIMBF₄–DMSO and AOEMIMBF₄–DMSO systems exhibit comparable interaction strengths. (3) The complexes were identified by the excess spectra and quantum chemical calculations, which are 2AOMMIMBF₄, 2AOMMIMBF₄–DMSO, AOMMIMBF₄–DMSO and [AOMMIM]⁺−DMSO complexes, respectively. This study enhances understanding of hydrogen bonding interactions between ester-functionalized IL and DMSO, and provides a theoretical basis for further applications of ester-functionalized ILs.

The decomposition mechanisms of crystalline and amorphous TNT were studied through ReaxFF-lg simulations under the heat-loaded and shock-loaded. Their differences were elucidated from the initial decay reactions, activation energy, products and the clusters. Results showed that the heat-induced pyrolysis of two systems differed slight, but the shock-induced pyrolysis differed large. The decomposition reactions of amorphous and crystalline models are similar, but the nitro oxidation of TNT is only found in amorphous. Dimerization and intermolecular H-transfer were found at the constant temperature and MSST simulations, and intermolecular O-transfer were only found at the constant temperature simulations. For MSST simulation, products in crystalline formed later than in amorphous, and the number of clusters in crystalline is much larger than in amorphous, which indicating crystalline TNT would be induced early through shock wave. These findings could help to increase the understanding for the thermolysis behavior and safety of crystalline and amorphous energetic materials.

While effective targeted delivery is a challenge in nanomedicine for the delivery of anti-cancer drugs, this work focuses on the potential use of Bismuthene and antimonene nanosheets as nanocarriers for cisplatin anti-cancer using DFT methods. The results indicate that, compared to antimonene, bismuthene demonstrates significantly better physical stability, drug release rate, solubility, and biocompatibility, making it an excellent candidate for drug delivery systems. The parallel and perpendicular orientations of the anticancer drug were adsorbed on both nanosheets; the parallel configuration was the most energetically favored with an adsorption energy of −0.79 eV at the parallel site. A charge transfer from the drug to the bismuthene sheet is also revealed by the electronic charge analysis and DOS calculation, thus confirming efficient drug adsorption. Modeling a proton attack on the drug and the carrier surface near the adsorption sites was performed to model drug release, showing the stability and potential of bismuthene in this aspect of drug release mechanisms. Further, with an approach to studying its interactions with biomolecules, interactions of the drug molecule have been analyzed with amino acids, showing that drugs interact efficiently. Further assessments concerning work function, recovery time, electron localization function, and frontier molecular orbital analyses leave no doubt that bismuthene has beneficial features over antimonene. These thorough assessments present bismuthene as a more promising nanocarrier for the delivery of anti-cancer drugs and open a potential pathway to enhance the efficacy of strategies against cancer treatment.

Understanding the carrier recombination processes in Sb₂Se₃ is essential for its optoelectronic applications. In this work, carrier recombination dynamics in Sb₂Se₃ were studied by broad band transient absorption spectroscopy. Firstly, the contribution of photothermal effect to the transient absorption spectrum was thoroughly discussed. It is confirmed that the excited state absorption (ESA) band with lifetime of several nanoseconds results from co-contribution of photo thermal effect and deep trapped carrier absorption. Secondly, the features of transient absorption spectrum on picosecond time scale were interpreted. The short-lived ESA band around 1000 nm was assigned to shallow trapped carrier absorption, while not band gap renormalization (BGR) or free carrier absorption. By globally fitting the transient absorption spectrum, the hot carrier cooling time and time constant for free carrier relax into deep trap state were determined to be 0.25∼0.45 ps and 3.1∼8.7 ps, respectively. Finally, we built up the carrier recombination model of Sb₂Se₃. The experimental results in this work will improve the understanding on the carrier recombination in Sb₂Se₃.

Titanium dioxide (TiO₂) is a semiconductor material that widely used in numerous applications due to its exceptional physical and chemical properties. This study explores the structural, electronic and elastic properties of TiO₂ phases in rutile, anatase and brookite under hydrostatic pressure up to 100 GPa. At 0 GPa, the computed lattice parameters and volumes align closely with experimental data. The band structure reveals that rutile and brookite exhibit direct band gaps while anatase shows an indirect band gap. Elastic properties including bulk modulus, shear modulus, Young’s modulus, Cauchy pressure, Pugh ratio and Poisson’s ratio were calculated using the Voigt-Reuss-Hill approximation. Our findings confirm the mechanical stability of all TiO₂ phases and offer insights that align with existing theoretical and experimental data. These findings provide a comprehensive understanding of behavior of TiO₂ under high-pressure condition which is crucial for optimizing its applications in various fields such as photocatalysis and solar cells.

The boiling point is a crucial indicator for assessing the suitability of insulating gases. Its theoretical prediction has consistently garnered significant attention from the scientific community. In this study, a boiling point database composed of hexa-element (C, H, O, N, F, S) for potential insulating gases was constructed. The model of Gradient Boosting Regression with RDKit descriptors (RDKit-GBR) achieved superior predictive ability on the test set with a coefficient of determination of 0.97, a mean absolute error of 17.74 °C, and a root-mean-squared error of 27.83 °C. The SHapley Additive exPlanations analysis showed that the “Ipc” feature in RDKit, which represents the spatial relationship and interaction between pairs of atoms within molecules, plays a central role in predicting the boiling points for insulation gases. Furthermore, the applicability of RDKit-GBR method was further validated across several elemental combinations. Eventually, compared with the previously reported models, the hexa-element model achieves excellent accuracy.

This work investigates the photoelectrochemical performance of an FTO (Fluorine-doped Tin Oxide) /WO₃ (tungsten trioxide) /BiVO₄ (bismuth vanadate) /TiO₂ (titanium dioxide) photoanode for water splitting. By forming a heterojunction between WO₃ and BiVO₄, charge separation and transportation are significantly enhanced, resulting in an improved photocurrent density. Surface modification with a thin TiO₂ layer further improves the stability of the photoanode without compromising its photocurrent. The SEM, XRD, and XPS analyses confirm the successful formation of the photoanode structure. The photoelectrochemical J-V curves demonstrate that the WO₃/BiVO₄ composite electrode outperforms single WO₃ and BiVO₄ electrodes, and the TiO₂ coating further enhances its performance. These findings provide valuable insights into optimizing BiVO₄-based photoanodes for efficient hydrogen production via water splitting.

Several fourth-order symmetric operator-splitting schemes with four and five stages for solving the time-dependent Schrödinger equation have been proposed. These schemes have been studied and compared with some optimal fourth- and sixth-order operator split schemes reported in the literature using a one-dimensional model and several realistic three-dimensional triatomic reactive scattering problems in Jacobi coordinates. Two new fourth-order operator-splitting schemes with four and five stages, which are more efficient than previously reported schemes, are recommended for the realistic numerical solution of the time-dependent Schrödinger equation in the field of molecular dynamics. It was found that the order-preserving method proposed by McLachlan works well for three-dimensional triatomic reactive scattering problems in Jacobi coordinates, despite the complicated form of the Hamiltonian.