Accurate and simple analytic representation of the electron-gas correlation energy

Removal of ochratoxin A from wine by adsorption-photocatalytic synergy of tubular TiO2/SiO2/g-C3N4: Mechanistic insights and degradation pathways

Consumption of contaminated wines is a significant source of ochratoxin A (OTA) intake in humans, yet existing techniques for OTA removal are inadequate. This study constructs a TiO2/SiO2/g-C3N4 catalyst (TiSiMs-TCN) with a tubular structure, capable of efficiently removing OTA from both simulated and real wines under visible light irradiation. The results of experiments, characterizations, and theoretical calculations demonstrate that the incorporation of silica enhances the adsorption capacity for OTA, and the tubular structure improves the catalyst's photoelectric properties. The internal electric field between TiSiMs and TCN facilitates electron transfer and the generation of active species, rapidly degrading the adsorbed OTA and promoting the regeneration of active sites, thus maintaining continuous adsorption-photocatalysis synergy. The OTA degradation pathway was analyzed using the Fukui index, electrostatic potential distribution, and intermediate product identification. Toxicological experiments confirm that TiSiMs-TCN is a safe and stable material capable of effectively detoxifying OTA contamination.

Temperature-dependent pathways in carbon dioxide electroreduction

Temperature affects both the thermodynamics of intermediate adsorption and the kinetics of elementary reactions. Despite its extensive study in thermocatalysis, temperature effect is typically overlooked in electrocatalysis. This study investigates how electrolyte temperature influences CO2 electroreduction over Cu catalysts. Theoretical calculations reveal the significant impact of temperature on *CO and *H intermediate adsorption thermodynamics, water microenvironment at the electrode surface, and the electron density and covalent property of the C-O bond in the *CH-COH intermediate, crucial for the reaction pathways. The theoretical calculations are strongly verified by experimental results over different Cu catalysts. Faradaic efficiency (FE) toward multicarbon (C2+) products is favored at low temperatures. Cu nanorod electrode could achieve a [Formula: see text] value of 90.1% with a current density of ∼400 mA cm-2 at -3 °C. [Formula: see text] and [Formula: see text] show opposite trends with decreasing temperature. The [Formula: see text] ratio can decrease from 1.86 at 40 °C to 0.98 at -3 °C.

Bilayer Kagome Ferrimagnet Exhibiting Exceptional Spontaneous Exchange Bias in TbMn6(Ge,Ga)6

Manipulating interlayer interactions in two-dimensional (2D) materials has led to intriguing behaviors. Borrowing these 2D signatures to bulk materials is likely to unlock exceptional properties. Here, we report an emergent 2D-like bilayer Kagome ferrimagnet through reducing the interbilayer magnetic interaction to nearly zero. This concept is realized within bulk TbMn6(Ge,Ga)6 compounds, characterized by an isolated and pure Mn Kagome lattice, simply by the chemical substitution of Ge with Ga. Specifically, the targeted compound TbMn6Ge5Ga1 exhibits a giant spontaneous exchange bias (SEB) of approximately 1.6 T, which is more than twice that observed in known materials. Field-dependent neutron diffraction reveals the robust nature of the compensated ferrimagnetic (FiM), characterized by almost two-thirds of the moments being pinned and irreversible under fields up to 9 T. Through magnetic and structural analysis, alongside theoretical calculations, we demonstrate that the substantial SEB is related to the intense competition between local robust and weak FiM states within the bilayer Kagome configuration, which are stabilized by an incommensurate spin arrangement. The concept of a bilayer Kagome magnet offers new opportunities for discovering attractive properties in 2D-like materials.

Nonempirical Adiabatic Connection Correlation Functional from Hartree-Fock Orbitals

We present a nonempirical strategy to construct a correlation functional rooted in the Møller-Plesset (MP) adiabatic connection (AC) formalism for the strong-interaction regime, which satisfies both the weak- and strong-interaction limits and describes accurately the uniform electron gas (UEG) model. The functional is based on Hartree-Fock (HF) orbitals and employs only the UEG and helium atom as model systems; thus, it can be considered a nonempirical and nonlinear generalization of post-HF approaches based on the second-order perturbation theory (MP2) correlation. The functional describes the correlation of atoms with 1 mHa/electron accuracy, and it is also accurate for jellium surface energies. Accurate tests using a nearly complete basis set on diverse systems and properties (atomization/interaction energies, dispersion forces, and ionization potentials) have shown an excellent performance of the functional that corrects the MP2 overbinding without error cancellation. The present investigation can open the way for the development of a new generation of post-HF functionals based on nonlinear MP2 contributions and strong-correlation ingredients.

Simple Linear Regression Models for Prediction of Ionization Energies, Electron Affinities, and Fundamental Gaps of Atoms and Molecules

Linear regression equations were developed for different density functionals using data from the CCCBDB, along with a test set of 89 ionization energies (IE) and 76 electron affinities (EA) so that experimental IE and EA can be predicted from orbital energies. Separate equations were determined for different classes of atoms and molecules. These relationships were also applied to all occupied orbitals to simulate the photoemission spectra of organic molecules with accuracy similar to that of other computational methods at a fraction of the cost. The error for large molecules (up to 200 atoms) can be below 0.2 eV with many functionals for the prediction of the IE and EA.

An Analysis of Regularized Second-Order Energy Expressions in the Context of Post-HF and KS-DFT Calculations: What Do We Gain and What Do We Lose?

Møller-Plesset second-order (MP2) perturbation energy expression has been a workhorse for quantum chemistry methods for many years due to its very appealing accuracy/cost ratio compared to more advanced methods. It has been widely utilized in the post-Hartree-Fock (post-HF) calculations and Kohn-Sham density functional theory (KS-DFT) to define, e.g., the double-hybrid class of density functional approximations. Although the list of successful applications of the MP2 method is quite long, it suffers from various limitations, e.g., in strongly correlated systems, divergence in small energy gap systems, or overestimation of binding energies for large noncovalently bonded species. In this work, we analyze a few of the most commonly utilized forms of regularized MP2 correlation energy expression in the context of post-HF and KS-DFT calculations. To this end, we perform various tests for model systems, e.g., homogeneous electron gas, one-dimensional Hubbard model, Harmonium atoms, and some real-life examples, to trace back the advantages and disadvantages of these formulas, providing practical guidelines for their utilization in everyday quantum chemical calculations.

Two-dimensional Janus X2SSe (X = Al, Ga or In) monolayers: potential photocatalysts with low effective mass

Janus 2D materials with high-efficiency solar energy conversion possess fine photocatalytic properties, which are current research hotspots in the field of photocatalysis. Herein, Janus X2SSe (X = Al, Ga or In) monolayers were proposed to explore their photocatalytic activities through first-principles calculation. The results demonstrated that the structures of Janus X2SSe (X = Al, Ga or In) monolayers were both dynamically and thermodynamically stable and exhibited excellent semiconductor properties. Additionally, a low effective mass for the photogenerated electrons and holes was observed. However, the Janus Al2SSe monolayer had an inappropriate band-edge potential, and the light-absorption edge corresponding to the maximum wavelength of the Janus Ga2SSe monolayer was not wide enough, which did not meet the conditions for an effective photocatalyst. Amazingly, the Janus In2SSe monolayer not only completely met the redox conditions for photocatalytic water decomposition but also presented visible-optical absorption with an absorption-band edge at 662 nm because of its indirect band gap of 1.52 eV, revealing its great application potential in photocatalysis. The above findings disclose the potential of the Janus In2SSe monolayer as a high-performance photocatalyst.

Computational Insights into the Structural and Optical Properties of Ag-Based Halide Double Perovskites

Lead-free halide double perovskites (HDP) have attracted enormous attention in recent years due to their low toxicity, excellent stability, tunable optical properties, and extensive range of compositional possibilities they present. In the very broad HDP family, Ag-based materials are of particular interest due to their easy synthesis, stability to light and moisture, and interesting optical properties, especially in the form of nanocrystals. Given the very large compositional space, theoretical studies play a crucial role in providing insights into the most promising dopant and possible defect interactions to guide the synthesis and explain the properties. In this review, we discuss recent theoretical works on Ag-based perovskites with an emphasis on density functional theory (DFT) calculations. The computational methods and tools are evaluated, assessing their relative strengths and limitations in their ability to clarify experimental results. We focus specifically on how lattice defects influence the structure and properties of HDP, including lattice and thermodynamic stability, band gap tuning, and photoluminescence.

Spectroscopic Manifestation of a Weak van der Waals Interaction Between trans-Stilbene and Hexagonal Boron Nitride Surface

The interaction between organic molecules and nanomaterials leads to complexation or the functionalization of later and modification of their properties, which are promising for electronics, terahertz technology, photonics, medical imaging, drug delivery, and other applications. Based on theoretical and experimental (THz, Raman, and fluorescence spectroscopy) studies, we analyzed the main spectroscopic characteristics of a weakly bound van der Waals complex of trans-stilbene (TS) molecule and hexagonal boron nitride (hBN). Raman scattering was demonstrated to be the most effective tool to confirm complex formation, exhibiting blue-shifted TS fingerprint lines in the TS + hBN Raman spectrum with respect to the spectra of pure TS or BN. These trends were also confirmed by density functional theory calculations. Coherent anti-Stokes Raman scattering microscopy was applied to check the complex structure. The THz absorption spectra demonstrated additional weak bands that can be assigned to the TS librations relative to the hBN surface, thus confirming the formation of the complex. The presence of hBN at the interface of the TS crystals also results in a relative enhancement of the 364 nm TS vibronic band in the TS + hBN fluorescence spectrum as well as faster FL decay kinetics. Based on the calculations performed in two different approaches, we also concluded that dispersion forces are critical for the adsorption of the TS molecules on the hBN surface.

Low-dimensional In2O3 nanostructures on MgO cubes

We report a successful synthesis of low-dimensional In2O3 nanostructures on MgO smoke particles using an innovative fabrication method. By co-combusting indium and magnesium in an oxygen-rich atmosphere, the energy released (heat) upon oxidation of Mg provides the conditions for the simultaneous evaporation of In resulting in the self-organized growth of indium oxide particles with consistent orientation. Notably, we report the stabilization of the typically unstable trigonal In2O3 polymorph on edges and corners of MgO cubes. These experimental results align well with the energetics extracted from atomistic models, which offers valuable insights into the thermodynamic factors driving the In2O3 stabilization on such less dense MgO terminations. This work marks a significant advancement in multi-metal oxide (MMO) research and nanostructure engineering.

Mechanisms and Origins of Regioselectivity in Rare-Earth-Catalyzed C-H Functionalization of Anisoles and Thioanisoles

The direct catalytic C-H functionalization of aromatic compounds such as anisoles and thioanisoles is of great interest and significance. However, achieving precise regioselectivity remains a major challenge. In this study, we conducted comprehensive density functional theory calculations to explore the mechanisms of rare-earth-catalyzed regioselective C-H alkylation, borylation, and silylation of anisole and thioanisole. The results reveal that in cationic C-H alkylation systems, the alkene insertion step follows a substrate-assisted mechanism, in which an additional substrate molecule acts as a ligand to facilitate the transformation. In neutral C-H borylation and silylation systems, although mononuclear hydride species readily dimerize into binuclear hydride species due to thermodynamic stability, the catalytic process predominantly proceeds via a mononuclear pathway. Furthermore, the origins of regioselectivity were thoroughly elucidated. A detailed analysis of electronic and steric effects in related transition states reveals that, for anisole, regioselectivity is primarily governed by ring strain. Since α-C(sp3)-H activation involves the formation of a highly strained three-membered ring, the reaction preferentially occurs at the ortho-C(sp2)-H site, forming a less strained four-membered ring. In contrast, for thioanisole, electronic effects play a decisive role, driving C-H activation at the more negatively charged α-C(sp3) site due to stronger metal-carbon interactions.

Tailoring frustrated Lewis pair catalysts for enhanced electrochemical CO2 reduction to multi-carbon fuels

Electrochemical reduction of CO2 to value-added chemical fuels is crucial for closing the anthropogenic carbon cycle and storing renewable energy; however, the development of a highly active and selective catalyst remains a significant challenge. Currently, CO2 reduction to hydrocarbons (especially C2 products) mainly relies on copper (Cu)-based catalysts, which often face considerable obstacles, including high energy barriers for C-C coupling and low product selectivity. In this study, we propose an innovative approach by introducing a metal-free frustrated Lewis pair (FLP) catalyst that utilizes the (110) surface of boron phosphide (BP) and boron arsenide (BAs) based on extensive first-principles calculations. Our findings reveal that these surface FLPs of BP and BAs (110) exhibit remarkable stability in electrochemical environments and efficiently capture and activate CO2 molecules through Lewis acid-base interactions. The "push-pull effect" facilitates the reduction of captured CO2 into CH4 and C2H6, featuring ultra-low potential-determining steps (PDS) of 0.11 and 0.28 eV, respectively. Furthermore, the unwanted competitive reaction, i.e. the hydrogen evolution reaction (HER), can be significantly suppressed during CO2 reduction, enhancing the selectivity for desired products. Overall, such a low PDS has never been achieved on any previously reported CO2 reduction catalysts, highlighting the potential of FLPs as a promising strategy for improving the catalytic performance of CO2 reduction reactions.

Systematic Study of Hard-Wall Confinement-Induced Effects on Atomic Electronic Structure

We point out that although a litany of studies have been published on atoms in hard-wall confinement, they have either not been systematic, having only looked at select atoms and/or select electron configurations, or they have not used robust numerical methods. To remedy the situation, we perform in this work a methodical study of atoms in hard-wall confinement with the HelFEM program, which employs the finite element method that trivially implements the hard-wall potential, guarantees variational results, and allows for easily finding the numerically exact solution. Our fully numerical calculations are based on nonrelativistic density functional theory and spherically averaged densities. We consider three levels of density functional approximations: the local density approximation employing the Perdew-Wang (PW92) functional, the generalized-gradient approximation (GGA) employing the Perdew-Burke-Ernzerhof (PBE) functional, and the meta-GGA approximation employing the r2SCAN functional. Importantly, the completely dissimilar density functional approximations are in excellent agreement, suggesting that the observed results are not artifacts of the employed level of theory. We systematically examine low-lying configurations of the H-Xe atoms and their monocations and investigate how the configurations─especially the ground-state configuration─behave as a function of the position of the hard-wall boundary. We perform calculations with both spin-polarized as well as spin-restricted densities and demonstrate that spin-polarization effects are significant in open-shell configurations, even though some previous studies have only considered the spin-restricted model. We demonstrate the importance of considering ground-state changes for confined atoms by computing the ionization radii for the H-Xe atoms and observe significant differences to earlier studies. Confirming previous observations, we identify electron shifts on the outermost shells for a majority of the elements: valence s electrons are highly unfavored under strong confinement, and the high-lying 3d and 4f orbitals become occupied in atoms of periods 2-3 and 3-4, respectively. We also comment on deficiencies of a commonly used density-based estimate for the van der Waals (vdW) radius of atoms and propose a better behaved variant in terms of the number of electrons outside the vdW radius that we expect will prove useful in future studies.

Strain Engineering the Optoelectronic and HER Behavior of MoS2/ZnO Heterojunction: A DFT Investigation

The rational design of heterojunctions by coupling two or more two-dimensional (2D) materials is regarded as a feasible strategy to efficiently enhance photocatalytic-hydrogen performance by capturing solar energy to address the increasing global energy crisis. In this work, a functional MoS2/ZnO heterojunction is proposed based on first-principles simulation. Our results reveal that the photogenerated electrons and holes in the MoS2/ZnO heterojunction follow a specific Z-scheme pathway, highly facilitating redox reactions and optimizing optical properties in the visible-light region. Under external strain, the MoS2/ZnO heterojunction demonstrates improved HER performance and remarkable optical-harvesting capabilities. Interestingly, the HER free energy for the heterojunction is only -0.04 eV under -5% compressive strain, highlighting its promising potential for photocatalytic hydrogen production. We observe that the absorption edge of the spectrum shifts gradually to the infrared region with increasing tensile biaxial strains, whereas compressive biaxial strains result in a blue-shift absorption spectrum. Additionally, all heterojunctions achieve excellent solar-to-hydrogen (STH) efficiencies exceeding 10%, demonstrating their capability to store sufficient solar energy. Our work offers a novel strategy for exploring highly efficient photocatalysts in the field of hydrogen energy with the ability to modulate their activity through external strain.

Alkaline Earth Metal Ions Dynamics in Mixed Ionic-Electronic Conductors of Graphite Intercalation Compounds

Materials that effectively facilitate the transport of ionic and electronic charges are crucial for advancing technological innovations in next-generation energy storage devices. This work proposed a new class of high-performance mixed ionic-electronic conductors (MIECs) in graphite intercalation compounds with the composition XC6 (X = {Ca, Sr, and Ba}) using molecular dynamics based on machine learning force fields combined with first-principles calculations. The calculated mean squared displacement and radial distribution functions indicate that CaC6, SrC6, and BaC6 transition to the superionic state at temperatures of 1500, 1800, and 2100 K, respectively. Alkaline earth metal cations can diffuse through two pathways via the vacancy migration mechanism: they can either move across carbon-carbon covalent bonds or migrate to the position above a carbon atom, subsequently diffusing to the center of an adjacent carbon hexagon. Additionally, these materials exhibit high ionic conductivity and excellent thermal and mechanical stability. The results suggest that the introduction of defects effectively regulates the superionic transition temperature, and CaC6 with 10% defects achieves a conductivity of approximately 0.05 S cm-1 at 550 K. We provide a new prospect from the perspective of ion dynamics to design advanced MIECs as high-temperature-resistant electrodes and interface improvement materials.

Regulation of Refractive Index by Halogens in Two-Dimensional Layered Methylsulfonate Halides

Herein, a series of unprecedented alkaline earth metal methylsulfonate halides, M(SO3CH3)X·nH2O (M = Sr, Ba; X = Cl, Br, I; n = 2, 4), and Ba2(SO3CH3)3I·4H2O were synthesized. They all feature two-dimensional (2D) layered structures with halogen elements inserted between the 2D layers constructed by metal ions and [SO3CH3] groups, which are suitable for exploring the influence of halogens on their refractive index. The refractive indexes both parallel and (almost) perpendicular to the 2D layers were calculated through theoretical calculations. We found that the nonpolar halogens exhibited different enhancement in the two directions. The result may guide regulating the birefringence properties of such 2D crystal materials. Besides, the ultraviolet (UV) cutoff edge of Sr(SO3CH3)Cl·4H2O and Ba(SO3CH3)Cl·4H2O can reach 183 and 184 nm, respectively, indicating their potential application in the deep-UV region.

Tunable Polariton Rabi Oscillation in Phase-Changing Perovskite Microcavities

Exciton-polaritons are composite quasiparticles hybridized between excitons and photons, which are very promising to develop quantum information devices such as entangled photon pair sources and polariton qubit devices by utilizing the fascinating properties of strong nonlinearity, Bose-Einstein condensation, and superfluidity. Organic-inorganic hybrid lead halide perovskites have attracted much interest in cavity quantum electrodynamics due to their excellent excitonic properties, including strong exciton binding energy and high oscillation strength. Here, tunable Rabi oscillation of exciton-polaritons in the lead halide perovskite microcavity is demonstrated, which experiences a phase transition between orthorhombic, tetragonal, and cubic phases by varying the temperature. Over the phase transition, the Rabi frequency is probed by tracing the dispersion relation of the exciton-polaritons using Fourier plane spectroscopy. Due to the emergence of ferroelectricity in the tetragonal phase of the perovskites, the Rabi splitting can be tuned by ≈20%, while the corresponding exciton oscillator strength is varied by ≈44%. These results provide insight into novel functionalities of polariton devices by utilizing ferroic semiconductors, which can facilitate the development of tunable quantum devices.

Promoting gas adsorption and charge transfer by activating iron incorporation sites for high performance trimethylbenzene sensing

The interaction between the surface and the target gas is the key to determining gas sensing performances of sensing materials, and revealing the interaction mechanism between the two still faces challenges. Herein, activating iron incorporation sites strategy is applied to address this issue. The gas sensor based on iron incorporation Co3O4 hierarchical porous architectures shows a significant gas selectivity toward trimethylbenzene, high sensing response, well long-term stability, rapid response/recovery speed and superior humidity resistance. It can be found that the sensing responses are positively correlated with the number and the species of hydrogen substituents on the benzene rings. In contrast, Co3O4 without iron incorporation does not exhibit any gas sensing performance. The density functional theory (DFT) calculations confirm that strong trimethylbenzene adsorption and charge transfer between FeCo sites and benzene ring of gases molecules lead to significantly enhanced trimethylbenzene gas sensing performance.

Graphene-Supported Cun (n = 5, 6) Clusters for CO2 Reduction Catalysis

In recent years, driven by the swift progress in nanotechnology and catalytic science, researchers in the field of physical chemistry have been vigorously exploring novel catalysts designed to enhance the efficiency and selectivity of a broad spectrum of chemical reactions. Against this backdrop, Cu clusters supported on defective graphene (Cun@GR, where n = 5, 6) function as two-dimensional nanocatalysts, demonstrating exceptional catalytic activity in the electrochemical reduction of carbon dioxide (CO2RR). A comprehensive investigation into the catalytic properties of these materials has been undertaken using density functional theory (DFT) calculations. By tailoring the configuration of Cun@GR, specific reduction products such as CH4 and CH3OH can be selectively produced. The product selectivity is quantitatively analyzed through free energy calculations. Remarkably, the Cu5@GR catalyst enables the electrochemical reduction of CO2 to CH4 with a significantly low overpotential of -0.31 eV. Furthermore, the overpotential of the hydrogen evolution reaction (HER) is higher than that of the conversion of CO2 to CH4; hence, the HER is unlikely to interfere and impede the efficiency of CH4 production. This study demonstrates that Cu5@GR offers low overpotential and high catalytic efficiency, providing a theoretical foundation for the design and experimental synthesis of composite nanocatalysts.

Efficient Alkaline Freshwater/Seawater Hydrogen Production via Heterogeneous N-Doped FeMoO4/Mo2N Rod-Shaped Electrocatalysts

Durable and efficient Fe-based electrocatalysts in alkaline freshwater/seawater electrolysis is highly desirable but persists a significant challenge. Herein, we report a durable and robust heterogenous nitrogen-doped FeMoO4/Mo2N rod-shaped catalyst on nickel foam (denoted NF@FMO/MN) affording hydrogen evolution reaction (HER) low overpotentials of 23/29 mV@10 mA cm-2 and 112/159 mV@100 mA cm-2 in both alkaline freshwater/seawater electrolytes, respectively. These results are significantly superior to the pristine FeMoO4 catalyst. Theoretical calculations consistently reveals that the combination of N-FeMoO4 and Mo2N effectively reduces water activation energy barrier, modulates the sluggish water-dissociation kinetics and accelerates the hydrogen adsorption process for efficient HER. The enhanced HER performance of the as-designed NF@FMO/MN catalyst is attributed to the in situ hetero-interfacial engineering between N-doped FeMoO4 and Mo2N. This present work nurtures the progress of FeMo-based electrocatalysts in alkaline freshwater/seawater electrolysis.

Hydroxylation Strategy Enables Ru-Mn Oxide for Stable Proton Exchange Membrane Water Electrolysis under 1 A cm-2

Ruthenium (Ru)-based catalysts have demonstrated promising utilization potentiality to replace the much expensive iridium (Ir)-based ones for proton exchange membrane water electrolysis (PEMWE) due to their high electrochemical activity and low cost. However, the susceptibility of RuO2-based materials to easily be oxidized to high-valent and soluble Ru species during the oxygen evolution reaction (OER) in acid media hinders the practical application, especially under current density above 500 mA cm-2. Here, a manganese-doped RuO2 catalyst with the hydroxylated metal sites (i.e., H-Mn0.1Ru0.9O2) is synthesized for acidic OER assisted by hydrogen peroxide, where the hydroxylation results in the valence state of the Ru sites below +4. The H-Mn0.1Ru0.9O2 catalyst demonstrates an overpotential of 169 mV at 10 mA cm-2 and promising stability for an OER over 1000 h in an acidic electrolyte. A PEMWE device fabricated with the H-Mn0.1Ru0.9O2 catalyst as the anode shows a current density of 1 A cm-2 at ∼1.65 V, along with a low degradation over continuous tens of hours. Differential electrochemical mass spectrometry (DEMS) results and theoretical calculations confirm that H-Mn0.1Ru0.9O2 performs the OER through the adsorbate evolution mechanism (AEM) pathway, where the synergistic effect of hydroxylation and Mn doping in RuO2 can effectively enhance the stability of Ru sites and lattice oxygen atoms.

Atomic ionization: sd energy imbalance and Perdew-Zunger self-interaction correction energy penalty in 3d atoms

To accurately describe the energetics of transition metal systems, density functional approximations (DFAs) must provide a balanced description of s- and d- electrons. One measure of this is the sd transfer error, which has previously been defined as [Formula: see text]. Theoretical concerns have been raised about this definition due to its evaluation of excited-state energies using ground-state DFAs. A more serious concern appears to be strong correlation in the 4s2 configuration. Here, we define a ground-state measure of the sd energy imbalance, based on the errors of s- and d-electron second ionization energies of the 3d atoms, that effectively circumvents the aforementioned problems. We find an improved performance as we move from the local spin density approximation (LSDA) to the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) to the regularized and restored Strongly Constrained and Appropriately Normed (r2SCAN) meta-GGA for first-row transition metal atoms. However, we find large (∼2 eV) ground-state sd energy imbalances when applying a Perdew-Zunger 1981 self-interaction correction. This is attributed to an "energy penalty" associated with the noded 3d orbitals. A local scaling of the self-interaction correction to LSDA results in a balance of s- and d-errors.

In/Outside Catalytic Sites of the Pore Walls in One-Dimensional Covalent Organic Frameworks for Oxygen Reduction Reaction

Pore channels play a decisive role in mass transport in catalytic systems. However, the influences of the location of catalytic sites inside or outside of the pore walls on the performance were still under-explored due, because it is difficult to construct sites anchored in or outside of pore walls. Herein, one-dimensional covalent organic frameworks with precisely anchored active sites were used to explore the effects of channels on a typical oxygen reduction reaction (ORR) catalysis. Electrocatalytic evaluations showed that single Pt sites located inside of the channels exhibited higher kinetic activity compared to those anchored outside. The in situ spectroscopic analysis revealed that local reconstruction of Pt-Cl breaking and potential-induced anion transport occurred more effectively inside the channels. The superior anion transportability and kinetic activity of the inside-channel active sites also facilitated *OH desorption during the ORR process outperforming their outside-channel counterparts. The results of this study provide strategies for designing active sites in porous catalysts for heterogeneous catalysis.

Assessing Cu3BiS3 for Thin-Film Photovoltaics: A Systematic DFT Study Comparing LCAO and PAW Across Multiple Functionals

Cu3BiS3 (CBS) has emerged as a promising earth-abundant absorber for thin-film photovoltaics, offering a sustainable alternative to conventional technologies. However, ab initio studies on its optoelectronic properties remain scarce and often yield contradictory results. This study systematically examines the influence of two density functional theory (DFT) methodologies, linear combination of atomic orbitals (LCAO) and projector augmented wave (PAW), on the structural and electronic properties of CBS, aiming to establish a reliable computational framework for future research. With this in mind, we also assessed the impact of a wide range of exchange-correlation (XC) functionals within both methods, including 6 from the local density approximation (LDA) family (HL, PW, PZ, RPA, Wigner, XA), 10 from the generalized gradient approximation (GGA) family (BLYP, BP86, BPW91, GAM, KT2, PBE, PBEsol, PW91, RPBE, XLYP), 2 meta-GGA functionals (SCAN, R2SCAN), and the hybrid HSE06 functional. Both LCAO and PAW consistently predict an indirect bandgap for CBS across all XC functionals, aligning with most previous DFT studies but contradicting experimental reports of a direct transition. The LDA and meta-GGA functionals systematically underestimated the CBS bandgap (<1 eV), with further reductions upon structural relaxation. GGA functionals performed better, with BLYP and XLYP yielding the most experimentally consistent results. The hybrid HSE06 functional substantially overestimated the bandgap (1.9 eV), with minimal changes after relaxation. The calculated hole and electron effective masses reveal strong anisotropy along the X, Y, and Z crystallographic directions. Additionally, CBS exhibits an intrinsic p-type nature, as the Fermi level consistently lies closer to the valence band maximum across all methods and functionals. However, the PAW method generally predicted more accurate lattice parameters than LCAO; the best agreement with experimental values was achieved using the PW91 (1.2% deviation) and HSE06 (0.9% deviation) functionals within LCAO. Based on these findings, we recommend the PW91 functional with LCAO for structural optimizations in large supercell studies of CBS dopants and/or defects and BLYP/XLYP for electronic properties.

Boosting Amino Acid Synthesis with WOx Sub-Nanoclusters

The conversion of nitrate-rich wastewater and biomass-derived blocks into high-value products using renewably generated electricity is a promising approach to modulate the artificial carbon and nitrogen cycle. Here, a new synthetic strategy of WOx sub-nanoclusters is reported and supported on carbon materials as novel efficient electrocatalysts for nitrate reduction and its coupling with α-keto acids. In acidic solutions, the NH3-NH2OH selectivity can also optimized by adjusting the potential, with the total FE exceeding 80% over a wide potential range. After introducing α-keto acids, the WOx/D-CB electrode achieves remarkable activity and selectivity toward C2-C6 amino acids. For glycine and alanine, impressive FEs of 49.34% and 38.22% based on transitional metal oxides can be obtained, surpassing those of WOx nanoclusters with larger size. In situ analysis and mechanistic studies reveal the critical role of WOx sub-nanoclusters in reducing the energy barriers of key steps in alanine synthesis. This work opens up new insights into the rational design of cluster catalysts to promote electrochemical amino acid synthesis.

The Photoinduced Response of Antimony from Femtoseconds to Minutes

As a phase change material (PCM), antimony exhibits a set of desirable properties that make it an interesting candidate for photonic memory applications. These include a large optical contrast between crystalline and amorphous solid states over a wide wavelength range. Switching between the states is possible on nanosecond timescales by applying short heating pulses. The glass state is reached through melting and rapid quenching through a supercooled liquid regime. While initial and final states are easily characterized, little is known about the optical properties on the path to forming a glass. Here we resolve the entire switching cycle of antimony with femtosecond resolution in stroboscopic optical pump-probe measurements and combine the experimental results with ab-initio molecular dynamics simulations. The glass formation process of antimony is revealed to be a complex multi-step process, where the intermediate transient states exhibit distinct optical properties with even larger contrasts than those observed between crystal and glass. The provided quantitative understanding forms the basis for exploitation in high bandwidth photonic applications.

"Bifunctional Strontium-Iron Doped Neodymium Cobaltite: A Promising Electrocatalyst for Intermediate Temperature Solid Oxide Fuel Cells and CO2 Electrolyzer"

A novel intermediate temperature solid oxide fuel cell cathode, Nd₀.₆₇Sr₀.₃₃Co₀.₈Fe₀.₂O₃- δ (NSCF), synthesized via auto-combustion, exhibits exceptional mixed ionic-electronic conducting properties with a cubic perovskite structure. At 800 °C, NSCF demonstrates high electrical (1003 S cm-1) and ionic (1.676 × 10⁻2 S cm-1) conductivities, with activation energies of 0.0335 and 0.481 eV, respectively. Electronic analysis confirms its metallic nature, while the calculated oxygen migration energy (0.455 eV) correlates with experimental ionic conduction activation energy. The negative bulk oxygen vacancy formation energy (-38.70 kcal mol-1) indicates efficient oxygen reduction reaction and CO₂ electrolysis kinetics. Electrical conductivity relaxation shows non-debye behavior, with Dchem of 5 × 10⁻⁴ cm2 s-1 and Kex of 6.450 × 10⁻⁴ cm -1s at 800 °C. NSCF exhibits low interfacial polarization resistance (0.05 Ω cm2) and area-specific resistance (0.025 Ω cm2), further reducing to 0.014 Ω cm2 with an NSCF-GDC Gadolinium doped ceria interlayer. An anode-supported cell achieves peak power densities of 2.27, 1.52, and 0.86 W cm- 2 at 800, 750, and 700 °C, respectively. In SOEC mode, NSCF demonstrates excellent CO₂ reduction capability of constant current density of -1.1 A cm- 2 with stable 55-h performance, which establishes its potential both as IT-SOFC cathode and CO2 electrolysis catalysts.

Mechanistic elucidation of Ta3N5/LaTiO2N heterojunction formation for improving photocatalytic activity

A Ta3N5/LaTiO2N junction is applied in photocatalytic reactions since the favorable band alignment of the two components promotes the separation of photogenerated carriers. This inference is mainly based on the properties of the two isolated, non-interacting materials. However, experiments reveal negligible information on the real nature of the interface, stoichiometry and composition of oxide layers and atomic arrangements in the heterojunction photocatalyst. In this work, we investigated the characteristics of Ta3N5/LaTiO2N using density functional theory calculations. Heterojunction models include the Ta3N5(110) surface interfaced with the LaTiO2N(010) surface and the Ta3N5(020) surface matched with the LaTiO2N(002) surface. Results show that owing to strong interfacial covalent bonds, the formation of a Ta3N5/LaTiO2N junction is an energetically favorable process. Ab initio molecular dynamics simulations also prove the stability of the studied interfacial structures. Light absorption becomes stronger and is extended after the formation of the heterojunction structure, which is favorable for enhancing the utilization efficiency of solar energy. Ta3N5/LaTiO2N is expected to behave as a type II heterojunction, irrespective of the surfaces of the two semiconductors involved in the junction, in which the band edges of Ta3N5 are lower in energy than those of LaTiO2N. This type of band alignment is favorable for the separation of photogenerated carriers upon photoexcitation, where electrons move toward Ta3N5 and holes toward LaTiO2N. On account of the larger driving force for separating charge carriers, the Ta3N5(110)/LaTiO2N(010) interface is predicted to outperform the Ta3N5(020)/LaTiO2N(002) one. The formation of an interfacial structure between Ta3N5 and LaTiO2N induces a more significant separation of photogenerated charge carriers, which may be the origin of an enhanced photocatalytic efficiency compared with isolated components.

Does Doping Always Increase Activity? Theoretical Insights into Non-metallic Doping Engineering of Corrugated Graphene

Conventional wisdom suggests that pristine graphene (Gr) is chemically inactive and that doping is an effective strategy to enhance its catalytic activity. Nevertheless, experimental evidence has demonstrated that non-metallic element (e.g., N, P, and S) doping of Gr significantly suppresses overall hydrogenation activity, yet the underlying mechanism remains to be elucidated. The present study investigates H2 activation on P- and S-doped corrugated Gr using density functional theory calculations. The results show that the H2 dissociation barriers on doped corrugated Gr are higher than those on undoped corrugated Gr, thus providing a plausible rationalization of the experimental observations. Importantly, the incorporation of non-metallic elements is found to exert a geometrical and electronic effect on Gr, signified by an increased distance and a decreased difference in the pz band center between dissociation sites, which is deleterious to the stabilization of transition states in H2 activation. This study provides theoretical insights for the design of efficient metal-free catalysts for hydrogenation via non-metallic doping engineering.

Microscopic Insights into the Catalytic Activity-Stability Trade-Off on Copper Nanoclusters for CO2 Hydrogenation to HCOOH

Lowly coordinated copper clusters are the most cost-effective benchmark catalysts for CO2 hydrogenation, but there is a meticulous balance between catalytic activity and stability. Herein, density functional theory (DFT) calculations are implemented to examine the catalytic performance of Cun nanoclusters (n = 4, 8, 16, 32) in CO2-to-HCOOH conversion. Facile activation of H2 is observed with significant electron transfer from Cun to antibonding orbitals of H2; conversely, the C-O bond of CO2 is poorly activated due to a low degree of orbital overlap. During the reaction, structural fluxionality occurs on Cu4 and Cu8 because of the low stability; however, negligible deformation is observed on Cu16 and Cu32. In addition, Cu16 achieves a good balance between the kinetics of each elementary reaction, which is, however, difficult to be maintained on Cu4, Cu8, and Cu32. Therefore, Cu16 satisfies the trade-off between activity and stability in CO2-to-HCOOH conversion. Energy decomposition analysis clarifies that the activation barrier of the second hydrogenation originates from the energy of hydride desorption, the electronic repulsion energy due to hydroxyl group formation, as well as the energy for local Cu-O bond cleavage. The high energy demand on the second hydrogenation is mainly sourced from the last term. From the bottom up, this work provides microscopic insights into the catalytic activity-stability trade-off in CO2 hydrogenation to HCOOH and would facilitate the rational design of advanced catalysts for the high-value utilization of CO2 exhaust gas.

Regulation of Two-Component Nanostructures at the Liquid-Solid Interface: Role of Pyridine Derivatives and Coronene

We investigate the self-assembly behaviors of the tetracarboxylic acid molecule (H4IMD), which contains an imidazole moiety, and explore the regulation by pyridine derivatives with varying backbones and the guest molecule coronene (COR). Two H4IMD molecules are linked through N-H···O hydrogen bonds to form a dimer, which spontaneously self-assembles into a grid structure via O-H···O hydrogen bonds. The addition of linear pyridine derivatives (BP and Bispy) can break some of the O-H···O hydrogen bonds, allowing these pyridine molecules to insert between the dimer columns. In contrast, the tripyridine derivative (TPYB) disrupts the original dimer structures, resulting in a completely altered nanostructure. Moreover, the H4IMD self-assembled structure can be regulated into a rhombus network by the coadsorption of COR molecules. Combining scanning tunneling microscopy and density functional theory calculations, this study elucidates the diverse structural variations and the underlying mechanisms, which provide new insights into molecular coassembly.

Ag Vacancies as "Killer-Defects" in CaAgSb Thermoelectrics

The AMX Zintl compound CaAgSb was recently identified as a promising thermoelectric material with high hole mobility and low lattice thermal conductivity. The single parabolic band model predicts that a zT of ∼1 can be achieved if the carrier concentration can be tuned to ∼1019 cm-3. However, the high inherent p-type carrier concentration of ∼1020 cm-3 in CaAgSb has limited further optimization of zT in p-type samples and has prevented n-type doping. In this work, we use a combination of computational and experimental tools to study the Fermi-level tunability of CaAgSb. Defect calculations based on density functional theory (DFT) reveal that acceptor-type defects, in particular Ag-vacancies, are the dominant defect across the full chemical potential space. This pins the Fermi energy within the valence band, leading to predicted p-type carrier concentrations that fluctuate within a narrow range. Crystal Orbital Hamilton Population (COHP) analysis shows that the Ag-Sb antibonding orbitals lie below the Fermi energy, which may explain the low Ag-vacancy formation energy in CaAgSb. Experimentally, we used a phase boundary mapping approach to explore the defect chemistry under different synthesis conditions. Samples were synthesized in the Ca-rich, Ag-rich, and Sb-rich regions of the phase diagram, and all were found to have high p-type carrier concentrations, ranging from 6.0 × 1019 to 1.8 × 1020 cm-3, and therefore similar thermal and electronic properties, consistent with the defect calculations. Taken together, our results confirm that Ag vacancies act as killer defects in CaAgSb, posing the primary challenge for further improvement of thermoelectric performance.

Effects of the Central Unit Structure, Lateral Substitution and Symmetry on the Mesomorphic Behavior of Some Bent-Core Azoester Derivatives

We report here the synthesis and characterization of some new bent-core asymmetric compounds derived from resorcinol whose thermal behavior has been analyzed by comparison with their analogs derived from 1,3-disubstituted benzene and 2,7-dihydroxynaphthalene containing azoester aromatic units and alkyl chain end. The asymmetric structures contain 4-(4-alkyloxyphenylazo)-benzoyl and 4-methoxy-benzoyl or 3-bromo-4-methoxy-benzoyl as side arms. The investigations have been carried out to reach a better understanding of the structure-properties relationship in such bent-shaped compounds. We observed that a change in molecular structure like the nature of the central core, the symmetry of the structure or the presence of polar lateral substituent influence not only liquid crystalline properties, but also the thermal behavior. The thermogravimetric analysis showed that the bent-core derivatives have a good thermal stability since the degradation of the compounds begins over the isotropization temperature. Theoretical calculations were performed to elucidate the behavior of the compounds. These can assist us in designing new molecules that exhibit specific mesomorphic properties.

Exploring atom-pairwise and many-body dispersion corrections for the BEEF-vdW functional

The Bayesian error estimation functional (BEEF-vdW) is widely used in surface science and catalysis, because it provides a balanced description of molecular, surface, and solid state systems, along with reliable error estimates. However, the nonlocal van-der-Waals density functional (vdW-DF2) employed in BEEF-vdW can be computationally costly and displays relatively low accuracy for molecular systems. Therefore, this work explores whether atom-pairwise and many-body dispersion treatments represent viable alternatives to using the vdW-DF2 functional with BEEF-vdW. To this end, we investigate the performance of commonly used atom-pairwise corrections [i.e., the Tkatchenko-Scheffler (TS) and the exchange-hole dipole moment (XDM) approaches] and many-body dispersion (MBD) treatments for molecular, surface, and solid-state systems. The results indicate that atom-pairwise methods such as TS and particularly XDM provide a good balance of cost and accuracy across all systems.

Easing Intermediates Search by Combining Spectroscopy and Multivariate Curve Reconstruction: [CuI(6,6'-dimethyl-2,2'-bipyridyl)2]PF6 Oxidation as Case Study

Despite their prevalence in catalysis, complex reaction mixtures are not trivial to investigate and disentangle. Different approaches can be applied to characterize them, even featuring low-dimensionality data sets. The liquid-phase reaction of [CuI(6,6'-dimethyl-2,2'-bipyridyl)2]PF6 (CuI) with tert-butyl hydroperoxide is investigated: two CuII species are found upon oxidation of the pristine complex, characterized by different spectroscopic and kinetics fingerprints. Coupling EPR and UV-vis spectroscopies with chemometric methods (namely, multivariate curve reconstruction, MCR) allowed for easily retrieving pure spectral features and concentration profiles. Spectrokinetic analysis independently showed an optimal agreement with kinetic outcomes from MCR. Finally, hypotheses on the nature of the CuII species are drawn on the basis of EPR fitting and quantum chemistry computations on a series of candidate structures. Beyond the accurate characterization of a model system, this study demonstrates the potential of coupling multivariate statistical techniques, experiments, and computations toward a quantitative understanding of electronic and kinetic information on complex chemical systems.

Data-Driven Studies of Two-Dimensional Materials and Their Nonlinear Optical Properties

We present a data-driven investigation leveraging high-throughput density functional theory calculations and machine learning to expedite the discovery of van der Waals (vdW) materials with nonlinear optical properties. Using the Computational 2D Materials Database, we analyze data from 345 noncentrosymmetric, nonmagnetic semiconductor monolayers, focusing on their second-order susceptibility tensors across multiple energy ranges suitable for various laser applications. By applying data mining techniques to extract key features from second harmonic generation spectra and employing machine learning models, we predict the second-order optical susceptibility for these materials. Our framework for this work facilitates the rapid identification of vdW materials for advanced photonics, optoelectronics, and data storage applications.

Alkyne dichotomy and hydrogen migration in binuclear cyclopentadienylmetal alkyne complexes

The structures and energetics of the binuclear cyclopentadienylmetal alkyne systems Cp2M2C2R2 (M = Ni, Co, Fe; R = Me and NMe2) have been investigated using density functional theory. For the Cp2M2C2(NMe2)2 (M = Ni, Co, Fe) systems the relative energies of isomeric tetrahedrane Cp2M2(alkyne) structures having intact alkyne ligands and alkyne dichotomy structures Cp2M2(CNMe2)2 in which the C[triple bond, length as m-dash]C triple bond of the alkyne has broken completely to give separate Me2NC units depending on the central metal atoms. For the nickel system Cp2Ni2C2(NMe2)2 as well as the related nickel systems Cp2Ni2(MeC2NMe2) and Cp2Ni2C2Me2 the tetrahedrane structures are clearly preferred energetically consistent with the experimental syntheses of several stable Cp2Ni2(alkyne) complexes. The tetrahedrane and alkyne dichotomy structures have similar energies for the Cp2Co2C2(NMe2)2 system whereas the alkyne dichotomy structures are significantly energetically preferred for the Cp2Fe2C2(NMe2)2 system. The potential energy surfaces for the Cp2M2(MeC2NMe2) and Cp2M2C2Me2 systems (M = Co, Fe) are complicated by low-energy structures in which hydrogen migration occurs from the alkyne methyl groups to one or both alkyne carbon atoms to give Cp2M2(C3H3NMe2) and Cp2M2(C3H3Me) derivatives with bridging metalallylic ligands, Cp2M2(CH2[double bond, length as m-dash]C[double bond, length as m-dash]CHNMe2) and Cp2M2(CH2[double bond, length as m-dash]C[double bond, length as m-dash]CHMe) with bridging allene ligands, as well as Cp2M2(CH2[double bond, length as m-dash]CH-CNMe2) and Cp2M2(CH2[double bond, length as m-dash]CH-CHMe) with bridging vinylcarbene ligands. For the Cp2M2C2Me2 (M = Co, Fe) systems migration of a hydrogen atom from each methyl group to an alkyne carbon atom can give relatively low-energy Cp2M2(CH2[double bond, length as m-dash]CH-CH[double bond, length as m-dash]CH2) structures with a bridging butadiene ligand. Five transition states have been identified in a proposed mechanism for the conversion of the Cp2Co2/MeC[double bond, length as m-dash]CNMe2 system to the cobaltallylic complex Cp2Co2(C3H3NMe2) with intermediates having agostic C-H-Co interactions and an activation energy barrier sequence of 13.1, 17.0, 15.2, and 12.0 kcal mol-1.

Mechanisms of Enhanced Electrochemical Performance by Chemical Short-Range Disorder in Lithium Oxide Cathodes

LiCoO2 has been one of the dominant cathode materials commercially used in rechargeable lithium-ion batteries, while the performance is severely limited by its low reversible capacity (∼140 mAh/g), primarily due to the destructive phase transitions at high voltages (>4.2 V vs Li/Li+), leading to structural degradation and rapid decay of capacity. A recent experimental study [Wang et al. Nature 2024, 629, 341] showed that chemical short-range disorder (CSRD) in LiCoO2 can effectively prevent phase transitions and structural deterioration. To better understand the underlying mechanisms, we carry out a theoretical study on CSRD-based LiCoO2 by performing ab initio molecular dynamics simulations accelerated by machine learning and find that CSRD effectively suppresses phase transitions from hexagonal to monoclinic at Li0.5CoO2 and from O3 to H1-3 at Li0.25CoO2. The enhanced phase stability is attributed to the reduced lattice variation in the c-axis, the increased oxygen vacancy formation energies, the higher oxygen dimer formation energies, and the stabilization of Co atoms in the Li layers during delithiation. The high Li+ diffusion coefficients are found to arise from the low-barrier 0-TM diffusion channels and an expanded diffusion network from 2D to quasi-3D induced by CSRD. Furthermore, CSRD narrows the band gap of LiCoO2 with enhanced electronic conductivity, driven by the changes in the Co valence state and the introduction of linear Li-O-Li configurations. Equally important, CSRD can also enhance the stability of Li-rich cathode Li1.2Co0.8O2 for high capacity and excellent cycling performance. This work provides theoretical insights into the effects of CSRD on LiCoO2 and Li-rich cathodes for rational design and synthesis.

Acentric Order-Disorder Zn3Sb4CO6F6: Crystal Structure, Dye Degradation, Cr(VI) Removal, Antibacterial Activity, and Catalytic C-C Bond Formation

Acentric Zn3Sb4CO6F6 has been synthesized by a hydrothermal technique. Single crystal X-ray diffraction study reveals that it crystallizes in cubic symmetry with a = 8.1480 (5) Å and Z = 2 (I4̅3 m). The carbon atom has tetrahedral coordination by Sb, either as an ordered structure at the center of the tetrahedron or as a disordered structure with carbon displaced toward three Sb atoms; the latter model leads to more acceptable Sb-C interatomic distances. Zn3Sb4CO6F6 has been established as the first multifunctional [M-L-C-O-F] compound, with exceptional properties, i.e., photocatalyst, adsorbent, catalyst for organic reactions, and antibacterial agent. This compound successfully degraded 89.5% of 50 mg/L methylene blue dye under solar illumination. It was also proved to be a proficient adsorbent toward Cr(VI) removal with qmax of 47.18 mg/g. The antibacterial activity was investigated by "agar cup assay" against both Gram-positive and Gram-negative bacterial strains. Zn3Sb4CO6F6 also functions as an excellent catalyst for the solvent-free Knoevenagel condensation reaction, with more than 90% yield. Theoretical investigations further proved that Zn3Sb4CO6F6 exhibits a direct band gap energy of 1.76 eV, which is consistent with the experimental findings. The synthesized compound was also characterized through fourier transform infrared spectroscopy, powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction study.

Interfacial charge transfer in g-C3N4/FeVO4/AgBr nanocomposite for efficient photodegradation of tetracycline antibiotic and Victoria blue dye

The study presents the fabrication and superior photoactivity of a ternary g-C3N4/FeVO4/AgBr heterojunction nanocomposite, synthesized via a chemical precipitation method for effective degradation of tetracycline (TC) and Victoria Blue (VB) dye under light illumination. The morphology and the crystal size of the synthesized nanocomposite were characterized by using FESEM and XRD and the calculated grain size (100.39 nm) is larger than the crystal size (48.14 nm) indicating strong interparticle bonding. The heterojunction design leverages dual S-scheme interfacial charge transfer, reducing electron-hole recombination as confirmed by optoelectronic and electrochemical techniques. The composite demonstrated superior performance, achieving 82.15% degradation of TC and 97.25% degradation of VB. The study highlights density functional theory (DFT) simulations and Mott-Schottky (MS) analysis, providing insight into the electronic structure, distribution of charge, and band alignments of the g-C3N4/FeVO4/AgBr nanocomposite. Electron spin resonance and radical scavenging experiments revealed holes and superoxide radicals as the primary species driving the degradation process. Furthermore, LC-MS analysis provided insights into the degradation pathways, confirming the conversion of TC and VB into non-toxic byproducts. The photocatalytic stability was confirmed through five consecutive cycles with minimal disruption in both performance and morphology, demonstrating its potential for wastewater treatment applications. Consequently, this study illustrates how the collaborative interplay of dual S-scheme charge migration and silver plasmonic effects enhances the efficiency of the g-C3N4/FeVO4/AgBr nanocomposite, offering a novel and highly effective solution for the degradation of complex pollutants in environmental remediation.

First principles study of double perovskites Li2AgAsX6 (X = Cl, Br, I) for optoelectronic and thermoelectric applications

The present communication aims to provide a theoretical examination of the structural, electronic, optical, transport, and mechanical characteristics of Li2AgAsX6 (X = Cl, Br, I) to check their potential for optoelectronic and thermoelectric applications. The structural analysis reveals their cubic symmetry, and their structural and thermodynamic stability is verified through assessments of their tolerance factors (0.96, 0.94, and 0.93) and formation energies (-3.63, -3.10, and -2.16 eV). Their mechanical stability and ductile nature are confirmed using elastic constants, Poisson's ratio, and Pugh's criterion. Analysis of the band structure exhibits bandgaps of 0.86, 0.56, and 0.22 eV for Cl-, Br- and I-based compositions. Analysis of their optical behavior is carried out in terms of complex dielectric constant, complex refractive index, optical conductivity, reflectivity, and loss, providing better insight into material characteristics. The highest absorption in the infrared region underscores their prospects as infrared detectors. Additionally, the materials exhibit high electrical conductivity, and ultra-low lattice thermal conductivity with a considerable figure of merit, highlighting their feasibility for thermoelectric devices.

Mechanical, structural, electronic, magnetic, and thermomagnetic properties of the full-Heusler Fe2MnAs1-xSix alloy using DFT and Monte Carlo simulation

The thermomagnetic, electronic, structural, and mechanical properties of the Fe2MnAs1-xSix (x = 0, 0.25, 0.5, 0.75, and 1.0) full Heusler alloys were investigated using Monte Carlo simulation (MCs) and density functional theory (DFT). Both the pure and doped structures exhibit the L21 prototype, and there is a noticeable decline in the lattice parameter as the Si concentration increases. Electronic analysis was performed using Wien2k and the calculations were conducted using the full-potential linearized augmented plane wave (FP-LAPW) method implementing various approximations including GGA-PBE, mBJ-GGA, GGA + U, and PBEsol (GGAsol). Studying exchange coupling parameters revealed that ferromagnetic states primarily arise from the interactions between Fe-Mn and Fe-Fe in both pure and doped structures. The resultant Curie temperature ranged from 215 to 490 K by investigating the magnetic properties. Additionally, different mechanical properties such as Poisson's ratio, linear compressibility, anisotropy parameter, shear, bulk, and Young's modulus were examined for all the structures.

Dispersionless Nonhybrid Density Functional

A dispersion-corrected density functional theory (DFT+D) method has been developed. It includes a nonhybrid dispersionless generalized gradient approximation (GGA) functional paired with a literature-parametrized dispersion function. The functional's 9 adjustable parameters were optimized using a training set of 589 benchmark interaction energies. The resulting method performs better than other GGA-based DFT+D methods, giving a mean unsigned error of 0.33 kcal/mol. It even performs better than some more expensive meta-GGA or hybrid dispersion-corrected functionals. An important advantage of using the new functional is that its dispersion energy given by the D component is very close to the true dispersion energy at all intermolecular separations, whereas in other similarly accurate DFT+D approaches, such a dispersion contribution in the van der Waals minimum region is only a small fraction of the true value.

Rechargeable Lithium-Hydrogen Gas Batteries

The global clean energy transition and carbon neutrality call for developing high-performance batteries. Here we report a rechargeable lithium metal - catalytic hydrogen gas (Li-H) battery utilizing two of the lightest elements, Li and H. The Li-H battery operates through redox of H2/H+ on the cathode and Li/Li+ on the anode. The universal properties of the H2 cathode enable the battery to demonstrate attractive electrochemical performance, including high theoretical specific energy up to 2825 Wh kg-1, discharge voltage of 3 V, round-trip efficiency of 99.7 %, reversible areal capacity of 5-20 mAh cm-2, all-climate characteristics with a wide operational temperature range of -20-80 °C, and high utilization of active materials. A rechargeable anode-free Li-H battery is further constructed by plating Li metal from cost-effective lithium salts under a low catalyst loading of <0.1 mg cm-2. This work presents a route to design batteries based on catalytic hydrogen gas cathode for high-performance energy storage applications.

Machine Learning-Assisted High-Throughput Screening for Electrocatalytic Hydrogen Evolution Reaction

Hydrogen as an environmentally friendly energy carrier, has many significant advantages, such as cleanliness, recyclability, and high calorific value of combustion, which makes it one of the major potential sources of energy supply in the future. Hydrogen evolution reaction (HER) is an important strategy to cope with the global energy shortage and environmental degradation, and given the large cost involved in HER, it is crucial to screen and develop stable and efficient catalysts. Compared with the traditional catalyst development model, the rapid development of data science and technology, especially machine learning technology, has shown great potential in the field of catalyst development in recent years. Among them, the research method of combining high-throughput computing and machine learning has received extensive attention in the field of materials science. Therefore, this paper provides a review of the recent research on combining high-throughput computing with machine learning to guide the development of HER electrocatalysts, covering the application of machine learning in constructing prediction models and extracting key features of catalytic activity. The future challenges and development directions of this field are also prospected, aiming to provide useful references and lessons for related research.

Inhibition of CHI3L1 decreases N-cadherin and VCAM-1 levels in glioblastoma

BACKGROUND

The protein CHI3L1 contributes to cancer development by several mechanisms, including stimulation of angiogenesis and invasion as well as immunomodulatory effects. These properties make it a potential target for the development of targeted therapies in precision medicine. In this context, the particular potential of CHI3L1 inhibition could be considered in glioblastoma multiforme (GBM), whose tumors exhibit high levels of angiogenesis and increased CHI3L1 expression. This study aims to investigate whether inhibition of CHI3L1 in spheroids used as a GBM model affects the mechanisms of invasiveness; METHODS: We analyzed the interactions between CHI3L1 and the inhibitor G721-0282 in molecular docking and molecular dynamics (in silico) and infrared spectroscopy. Uptake of G721-0282 in GBM spheroids was measured using a label-free physical cytometer. Changes in E-, N- and VE-cadherins, VCAM-1, and EGFR were analyzed by immunohistochemical reactions, Western blot, and ddPCR methods in U-87 MG cells and GBM spheroids consisting of U-87 MG glioblastoma cells, HMEC-1 endothelial cells and macrophages; RESULTS: A direct interaction between CHI3L1 and G721-0282 was confirmed. G721-0282 decreased N-cadherins and VCAM-1 in GBM spheroids, but the changes in the 2D model of U-87 MG glioblastoma cells were different; CONCLUSION: Inhibition of CHI3L1 has the potential to reduce the invasiveness of GBM tumors. The 3D model of GBM spheroids is of great significance for investigating changes in membrane proteins and the tumor microenvironment.

Synergistic effect of multi-metal site provided by Ni-N4, adjacent single metal atom, and Fe6 nanoparticle to boost CO2 activation and reduction

Single transition metal (TM) atom embedded in nitrogen-doped carbon materials with M-Nx-C configuration have emerged as a promising class of electrocatalysts for electrochemical CO2 reduction (CO2RR). However, at high TM atom densities, a comprehensive understanding of the active site structure and reaction mechanisms remains a significant challenge, yet it is crucial for enhancing CO2RR performance. In this work, we use first-principles calculations to investigate the electrocatalytic performance of Ni-N4 sites for CO2 reduction to CO, co-assisted by neighboring TM atoms and a Fe6 nanoparticle. Unlike many previously studied Ni-N4 catalysts that maintain a linear CO2 structure, the combination of adjacent TM atoms and Fe6 induces bending and activation of CO2 at the Ni site, enhancing its protonation to form key *COOH intermediate while maintaining efficient *CO desorption. The newly designed hybrid electrocatalyst demonstrates a synergistic effect of multi-metal sites in boosting CO2 reduction to CO. Specifically, the TM atom facilitates C-Ni bond formation between the Ni site and *CO2/*COOH species, while Fe6 forms an Fe…O coordination bond. Detailed analysis of reaction mechanisms and energetics show that Ni-N4, co-assisted by a single TM atom and Fe6 (especially TM = Ni, Cu, or Ag), exhibits enhanced catalytic activity for CO production with a low limiting potential of -0.5 V. This work presents an effective strategy for improving the catalytic activity of single-atom catalysts (SACs) at high metal content.

Phase Engineering of ZnSe by Small Molecules as a High-Performance Protective Layer for Zn Anode

The practical application of aqueous zinc ion batteries is still hampered by the side reactions and dendrite growth on Zn anode. Herein, the phase engineering of ZnSe coating layer by incorporating small molecules is developed to enhance the performance of Zn anode. The unique electronic structure of ZnSe⋅0.5N2H4 promises strong adsorption for Zn atoms and enhanced ability to inhibit hydrogen evolution, thereby promoting uniform Zn deposition and preventing by-product and dendrite growth. Meanwhile, fast Zn2+ transfer and deposition kinetics are also demonstrated by ZnSe⋅0.5N2H4. As a result, the ZnSe⋅0.5N2H4@Zn symmetric cell achieves long-term cycling stability up to 1900 h and 300 h at high current densities of 5 mA cm-2 and 20 mA cm-2, respectively. The assembled ZnSe⋅0.5N2H4@Zn||NH4V4O10 full cell presents outstanding cycling stability and rate capability. This work highlights the key role of crystal phase control of protective layer for high-performance zinc anode.

Importance of Density for Phase-Change Materials Demonstrated by Ab Initio Simulations of Amorphous Antimony

Phase change materials (PCMs) serve as useful components in electronics and photonics. Here we demonstrate that various kinds of material properties of a PCM are significantly influenced by the realized mass density. Using ab initio simulations, we investigate supercooled-liquid antimony and the subsequent transition to a glassy phase. We observe a transition in the supercooled-liquid phase from an undistorted high-temperature to an increasingly Peierls-like distorted low-temperature phase. This transition also manifests in both the electronic density of states and optical properties. The strong dependence of these properties on mass density leads the way to explorations of property design for nanoconfined devices beyond the usual compositional modifications.

Ferromagnetic Fe-TiO2 spin catalysts for enhanced ammonia electrosynthesis

Magnetic field effects (MFE) of ferromagnetic spin electrocatalysts have attracted significant attention due to their potential to enhance catalytic activity under an external magnetic field. However, no ferromagnetic spin catalysts have demonstrated MFE in the electrocatalytic reduction of nitrate for ammonia (NO3RR), a pioneering approach towards NH3 production involving the conversion from diamagnetic NO3- to paramagnetic NO. Here, we report the ferromagnetic Fe-TiO2 to investigate MFE on NO3RR. Fe-TiO2 possesses a high density of atomically dispersed Fe sites and exhibits an intermediate-spin state, resulting in magnetic ordering through ferromagnetism. Assisted by a magnetic field, Fe-TiO2 achieves a Faradaic efficiency (FE) of up to 97% and an NH3 yield of 24.69 mg mgcat-1 at -0.5 V versus reversible hydrogen electrode. Compared to conditions without an external magnetic field, the FE and NH3 yield for Fe-TiO2 under an external magnetic field is increased by ~21.8% and ~ 3.1 times, respectively. In-situ characterization and theoretical calculations show that spin polarization enhances the critical step of NO hydrogenation to NOH by optimizing electron transfer pathways between Fe and NO, significantly boosting NO3RR activity.