Chemical Physics Letters最新文献

Ternary-type semiconductor chalcogenide materials are distinguished by their outstanding thermal performance and tunable optoelectronic features. The electronic structure, optical, and transport features of novel Zn₂SeX ternary (X=S, Te) semiconductors are investigated by employing the widely used density functional theory. Based on the band structure investigation, these materials were anticipated to have a direct energy gap. The results demonstrated that direct energy losses were caused by the orbitals hybridization of S-p and the Se/Te-d in both materials. Compared to Zn₂SeTe, Zn₂SeS has a wider band gap at the Γ-point, meaning that electrons will have a lower effective mass and atoms possess a greater effective mass. The elements of the complex dielectric function and the significant optical properties were explored for potential use in optoelectronic applications. The unique peaks in I(ω) confirm extensive absorption in the UV range. They may be employed as very effective ultraviolet-reflecting materials based on the peaks in the reflection spectrum that have been observed. Since both materials positive Seebeck coefficient display p-type conductivity over the whole temperature range.

In this investigation, Barium zirconate (BaZrO₃ or BZO) showcasing high photocatalytic efficacy was synthesized by the microwave-assisted hydrothermal method. Photocatalytic activity was investigated through the removal of the Rhodamine B (RhB) dye. Although it has a high band gap (∼5 eV), BZO showed the capacity to remove ∼ 56 % of RhB. Defects, hydroxyl radicals adsorbed on its surface and favorable electronic structure were factors that promoted photocatalytic activity. Furthermore, the BZO exhibited exceptional recyclability, underscoring its potential as a photocatalyst for environmental remediation applications.

We report a systematic study of magnetic transformation and magnetic critical behavior in the chiral magnet $\beta$-Mn type Co₇Zn₇Mn₆. It undergoes a paramagnetic-ferromagnetic phase transition around 190 K and shows a spin glass state at 18 K. The critical exponents $\beta =$ 0.685, $\gamma =$ 1.385, and $\delta =$ 3.03 are obtained by the investigation of magnetic field dependence on magnetic-entropy change and the calculation with Widom scaling relation. The reliability of critical exponents is confirmed by the scaling equation. The strong reversed site disorder of $\beta$-Mn type Co₇Zn₇Mn₆ results in the localized characterization of carriers and a slow development of ferromagnetic ordering state.

In this paper, MTDATA is selected as the electron donor and BPhen as the acceptor. The trianiline structure of the donor molecule provides a variety of charge transfer pathways for charge separation. Based on Marcus theory, the photoinduced charge transfer properties of non-fullerene acceptor organic solar cells (NFA-OSCs) in external electric field (F_ext) were studied. By analyzing the changes of reorganization energy (λ), Gibbs free energy (ΔG), electron transfer integral (V_da) and charge transfer rate under the influence of F_ext, it was found that F_ext can effectively regulate the charge transfer. Moreover, the change of charge transfer rate under F_ext is similar to V_da, indicating that V_da is the main factor affecting charge transfer rate. To a certain extent, this study provides theoretical support for improving the photoelectric performance of NFA-OSCs.

The hydrogen evolution reaction (HER) in Ag₁₂M clusters with first-row 3d metal (M) dopants is evaluated by means of density functional theory (DFT). The results show that the M dopants favor the highest coordination positions, except for M = Zn, favoring the surface position. The findings indicate that Ag₁₂Ti and Ag₁₂Cu clusters are suitable catalysts for HER applications, according to the adsorption energy and Gibbs free energy parameters. The interactions of the clusters with H can be explained by density of states analyses. The obtained results suggest that atomically precise doped Ag clusters are suitable targets as relevant candidates for HER applications.

AlCl⁺ as a potential interstellar molecule has attracted significant attention, but gaps remain in our understanding of its thermodynamic properties and spectral line intensities. This study employed the icMRCI+Q method to compute potential energy curves for the 13 Λ-S states of AlCl⁺. Based on these curves, spectroscopic parameters and vibrational–rotational energy levels were determined. Subsequently, partition functions were calculated over a temperature range from 50 K to 10000 K, and the thermodynamic properties were derived. Using transition dipole moments, the UV spectra for transitions from the ground state (X ²Σ⁺) to the third excited state (2²Π) were computed at 298.15 K.

For laser-cooling considerations, we have theoretically investigated the electronic structures of the XF⁻ (X=Li, Na, K, Rb) molecule. The potential existence of anions is initially examined through the analysis of their affinity energies and dipole moments of the corresponding neutral molecules. Subsequently, we excluded the effect of spin–orbit coupling on the molecular. Then the calculations reveal that XF⁻ (X=Li, Na, K, Rb) exhibits a highly diagonalized Franck-Condon factor and a short spontaneous radiation lifetime, facilitating the design of laser cooling schemes for each molecular ion. The findings provide an important reference for laser cooling experiments involving alkali metal fluoride anions.

Bismuth oxychloride (BiOCl), emerging as a novel environmentally friendly nanomaterial, possesses considerable potential for photocatalytic degradation of organic wastewater. However, inadequate active sites and inhibited electron separation efficiency severely hinder its visible-light photocatalytic activity. To address this issue, herein we present a facile approach to in-situ construct BiOCl three-dimensional (3D) flower-structure (BOC-F) with oxygen-enriched vacancies for abundant active sites and effective electron separation efficiency through morphology control and vacancy engineering. The visible photocatalytic activity of BOC-F and BiOCl with 2D flaky-structure (BOC-S) was assessed through a systematic examination of the degradation efficiencies of tetracycline hydrochloride (TC-HCl) and rhodamine B (RhB). Under visible light irradiation, BOC-F exhibited superior visible photocatalytic activity, effectively degrading tetracycline hydrochloride (TC-HCl) (20 mg/L) and rhodamine B (RhB) (200 mg/L) within 90 min and 20 min of light exposure, respectively. The findings elucidate that BOC-F, possessing a 3D flower structure, manifests a heightened concentration of oxygen vacancies in contrast to BOC-S, consequently yielding excellent performance. Moreover, The ESR test showed that singlet oxygen (¹O₂) and hole (h⁺) were two main active species in the photocatalytic degradation of BOC-F. This work not only furnishes a facile method for constructing oxygen-rich vacancies in BiOCl but also provides fresh insights into the potential for enhancing the visible photocatalytic properties of Bi-based materials through vacancy engineering.

Sodium oleate (NaOL) is commonly employed as a traditional organic collector during the flotation process of phosphate ore. However, the residual NaOL in mineral processing wastewater not only poses a great threat to the environment, but also reduces the qualities of subsequent flotation products. In this study, an effective adsorbent graphene oxide/polyethyleneimine (GP) composite hydrogel was prepared and applied for the adsorption of NaOL. The successful association between GO and PEI was elucidated through various characterizations. Further to that, the adsorption performance was systematically determined through adsorption isotherm, adsorption kinetics, co-existing ions and reusability experiments. The results clearly demonstrated that the adsorption behavior of NaOL could be well described by both pseudo-second-order (PSO) kinetic and Langmuir isotherm models. GP composite hydrogel was able to achieve superior NaOL adsorption with an excellent adsorption capacity (295.95 mg/g) and a quick kinetic (120 min). The existence of competitive ions, such as CO₃²⁻, SO₄²⁻ and PO₄³⁻, had a negative effect on NaOL adsorption. The mechanism investigation suggested that chemical adsorption and hydrogen bonds were central and played imperative roles for the adsorption of NaOL on GP composite hydrogel. Overall, the current work provides a valuable reference for the efficient adsorption of NaOL.

A unique hydrangea-like SnO₂ assembled by ultrathin nanosheets interlaced with veins was successfully prepared via hydrothermal process. The sensor based on this material exhibits excellent sensing properties toward formaldehyde at 170 °C, including a high response (8.5 to 1 ppm and 57.7 to 50 ppm), good selectivity, and quick response/recovery (7/16 s), with a detection limit of 3.9 to 80 ppb formaldehyde. These superior sensing characteristics can be attributed to the synergistic effect of the porous ultrathin nanosheets (∼12 nm) and the exposed (1 1 0) facets with more oxygen vacancies. The Density functional theory (DFT) calculations are applied to explore the formaldehyde sensing mechanism of the novel structure.