XPS Analysis of FeNiPS vdW Materials Used in the Hydrogen Evolution Processes.

In response to the global demand for sustainable energy solutions, the quest for stable and cost-effective hydrogen production has garnered significant attention in recent decades. Here, the emergence of layered metal phosphorus trichalcogenides (MPX, M: transition metal, X: chalcogen) materials and their two-dimensional counterparts with customizable composition and electronic structure holds great promise for such purposes. In the present study, we successfully synthesized large-scale and high-quality FePS, NiPS, and an alloyed counterpart, FeNiPS.

Electronic Correlations in FeNiPS Van der Waals Materials: Insights from Angle-Resolved Photoelectron Spectroscopy and DFT.

Recently layered antiferromagnetic materials with different magnetic orderings attract increased attention. It was found that these properties can be preserved down to the monolayer limit opening large perspectives for their applications in (opto)spintronics and sensing, however, lacking the experimental results on electronic structure studies. Here the results of angle-resolved photoelectron spectroscopy (ARPES) studies accompanied by DFT calculations for FeNiPS layered van der Waals (vdW) alloys are presented, addressing the effects of electronic correlations in these materials.

Probing Active Sites on Pristine and Defective MnPX (X: S and Se) Monolayers for Electrocatalytic Water Splitting.

The state-of-the-art density functional theory approach was used to study the structural and electronic properties of pristine and defective MnPX monolayers as well as their activity toward water and hydrogen evolution reaction (HER) catalytic performance. The adsorption behavior of HO on a pristine MnPX structure is of physisorption nature, whereas the adsorption energy is significantly increased for the defective structures. At the same time, the water dissociation process is more energetically favorable, and the reactivity of MnPX is determined by the vacancy configuration.

Influence of acoustic cavitation on physico-chemical, organoleptic indicators and microstructure of Adyghe cheese produced from cow and goat milk.

In this article, we studied the effect of acoustic cavitation on the physicochemical and organoleptic parameters, the microstructure of Adyghe cheese made from cow's and goat's milk, and their mixture. The experimental conditions, optimal modes of ultrasonic cavitation treatment of cow and goat milk, and their mixtures are determined. It was found that high-frequency acoustic cavitation improves the physico-chemical and organoleptic indicators of cheese.

Dual Character of the Insulating State in the van der Waals FeNiPS Alloyed Compounds.

The electronic structure of the alloyed transition-metal phosphorus trichalcogenide van der Waals FeNiPS compounds is studied using X-ray absorption spectroscopy and resonant photoelectron spectroscopy combined with intensive density functional theory calculations. Our systematic spectroscopic and theoretical data demonstrate the strong localization of the Fe- and Ni-ions-derived electronic states that leads to the description of the spectroscopic data as belonging simultaneously to Mott-Hubbard and charge-transfer insulators. These findings reveal FeNiPS as unique layered compounds with dual character of the insulating state, pointing to the importance of these results for the description and understanding of the functionality of this class of materials in different applications.

Mixed Insulating State for van der Waals CoPS.

Large-scale high-quality van der Waals CoPS single crystals are synthesized using a chemical vapor transport (CVT) method. The crystallographic structure and electronic properties of this layered material are systematically studied using different spectroscopic methods (XPS, NEXAFS, and resonant photoelectron spectroscopy) accompanied by density functional theory (DFT) calculations. All experimental and theoretical data allow assignment of this material to the class of mixed Mott-Hubbard/charge-transfer insulator with ≅ Δ.

Semiconducting eutectic materials for photocatalysis and photoelectrochemistry applications: a perspective.

The world of semiconductors has drastically improved human lifestyle due to its versatile applications. The demand for new efficient semiconductors is increasing day by day, giving birth to the idea of new synthesis methods. Here, the importance of semiconductor eutectic materials has been presented, as one of the potential candidates for solar-based devices such as photo-anodes for water splitting, along with the micro (μ) pulling method (as a synthesis method for semiconductor eutectic materials).

The effects of ultrasonic treated whey on the structure formation in food systems based on whey in combination with pectin and agar-agar.

We studied the effects of ultrasonicated whey in food systems with the structure-forming additives such as pectin and agar-agar. The high-intensity (45KHz, 40 W with cavitation) ultrasonic treated whey was used. The conditions and optimal modes of cavitation based ultrasonic processing of curd milk whey have been determined.

Electronic and Magnetic Properties of the Graphene/Y/Co(0001) Interfaces: Insights from the Density Functional Theory Analysis.

The effect of Y intercalation on the atomic, electronic, and magnetic properties of the graphene/Co(0001) interface is studied using state-of-the-art density functional theory calculations. Different structural models of the graphene/Y/Co(0001) interface are considered: (i) graphene/Y/Co(0001), (ii) graphene/1ML-YCo/Co(0001), and (iii) graphene/bulk-like-YCo(111). It is found that the interaction strength between graphene and the substrate is strongly affected by the presence of Y at the interface and the electronic structure of graphene (doping and the appearance of the energy gap) is defined by the Y concentration.

Mott-Hubbard insulating state for the layered van der Waals [Formula: see text] (X: S, Se) as revealed by NEXAFS and resonant photoelectron spectroscopy.

A broad family of the nowadays studied low-dimensional systems, including 2D materials, demonstrate many fascinating properties, which however depend on the atomic composition as well as on the system dimensionality. Therefore, the studies of the electronic correlation effects in the new 2D materials is of paramount importance for the understanding of their transport, optical and catalytic properties. Here, by means of electron spectroscopy methods in combination with density functional theory calculations we investigate the electronic structure of a new layered van der Waals [Formula: see text] (X: S, Se) materials.

-Chloridolithates from Ionothermal Synthesis.

Anionic lithium-containing species were predicted to impact ionic liquid-based electrochemical applications but have hitherto never been isolated from ionic liquid systems. Here, we report the first representatives of this class of compounds, -chloridolithates, comprising [LiCl] and [LiCl] polyanions from ionothermal reactions. Such compounds are obtained at moderate temperatures with imidazolium-based ionic liquids and LiCl.

Topological Quasi-2D Semimetal CoSnS: Insights into Electronic Structure from NEXAFS and Resonant Photoelectron Spectroscopy.

The electronic structure of the natural topological semimetal CoSnS crystals was studied by using near-edge X-ray absorption spectroscopy (NEXAFS) and resonant photoelectron spectroscopy (ResPES). Although, the significant increase of the Co 3d valence band emission is observed at the Co 2p absorption edge in the ResPES experiments, the spectral weight at these photon energies is dominated by the normal Auger contribution. This observation indicates the delocalized character of photoexcited Co 3d electrons and is supported by the first-principle calculations.

Second Floor of Flatland: Epitaxial Growth of Graphene on Hexagonal Boron Nitride.

In the studies presented here, the subsequent growth of graphene on hexagonal boron nitride (h-BN) is achieved by the thermal decomposition of molecular precursors and the catalytic assistance of metal substrates. The epitaxial growth of h-BN on Pt(111) is followed by the deposition of a temporary Pt film that acts as a catalyst for the fabrication of the graphene sheet. After intercalation of the intermediate Pt film underneath the boron-nitride mesh, graphene resides on top of h-BN.

Adsorption of water on the pristine and defective semiconducting 2D CrPmonolayers (: S, Se).

The effect of vacancy and water adsorption on the electronic structure of semiconducting 2D trichalcogenide material CrP(: S, Se) is studied using state-of-the-art density functional theory (DFT) approach. It is found that chalcogen vacancies play a minor role on the electronic structure of CrPin the vicinity of the Fermi level leading to the slightly reduced band gap for these materials, however, inducing strongly localised defect states which are placed in the energy gap formed by the valence band states. Our DFT calculations show that the interaction of water molecules with CrP, pristine and defective, can be described as physisorption and the adsorption energy for HO is insensitive to the difference between pristine and chalcogen-defective surface of trichalcogenide material.

Correlations in the Electronic Structure of van der Waals NiPS Crystals: An X-ray Absorption and Resonant Photoelectron Spectroscopy Study.

The electronic structure of high-quality van der Waals NiPS crystals was studied using near-edge X-ray absorption spectroscopy (NEXAFS) and resonant photoelectron spectroscopy (ResPES) in combination with density functional theory (DFT) approach. The experimental spectroscopic methods, being element specific, allow one to discriminate between atomic contributions in the valence and conduction band density of states and give direct comparison with the results of DFT calculations. Analysis of the NEXAFS and ResPES data allows one to identify the NiPS material as a charge-transfer insulator.

Intercalation of Mn in graphene/Cu(111) interface: insights to the electronic and magnetic properties from theory.

The effect of Mn intercalation on the atomic, electronic and magnetic structure of the graphene/Cu(111) interface is studied using state-of-the-art density functional theory calculations. Different structural models of the graphene-Mn-Cu(111) interface are investigated. While a Mn monolayer placed between graphene and Cu(111) (an unfavorable configuration) yields massive rearrangement of the graphene-derived [Formula: see text] bands in the vicinity of the Fermi level, the possible formation of a [Formula: see text]Mn alloy at the interface (a favorable configuration) preserves the linear dispersion for these bands.

Graphene Layer Morphology as an Indicator of the Metal Alloy Formation at the Interface.

The intercalation of different species in graphene-metal interfaces is widely used to stabilize the artificial phases of different materials, which in some cases leads to the formation of the surface alloys between atoms of the guest metal and the substrate. Here, the interfaces of graphene with Ru(0001) and Ir(111) were modified using intercalation of a thin Mn layer and investigated by means of scanning tunneling microscopy (STM) accompanied by density functional theory (DFT) calculations. It is found that Mn forms a pseudomorphic layer on Ru(0001) under a strongly buckled graphene layer.

Epitaxial graphene/Ge interfaces: a minireview.

The recent discovery of the ability to perform direct epitaxial growth of graphene layers on semiconductor Ge surfaces led to a huge interest in this topic. One of the reasons for this interest is the chance to overcome several present-day drawbacks on the method of graphene integration in modern semiconductor technology. The other one is connected with the fundamental studies of the new graphene-semiconductor interfaces that might help with the deeper understanding of mechanisms, which governs graphene growth on different substrates as well as shedding light on the interaction of graphene with these substrates, whose range is now spread from metals to insulators.

Quantum Well States for Graphene Spin-Texture Engineering.

The modification of graphene band structure, in particular via induced spin-orbit coupling, is currently a great challenge for the scientific community from both a fundamental and applied point of view. Here, we investigate the modification of the electronic structure of graphene (gr) initially adsorbed on Ir(111) via intercalation of one monolayer Pd by means of angle-resolved photoelectron spectroscopy and density functional theory. We reveal that for the gr/Pd/Ir(111) intercalated system, a spin splitting of graphene π states higher than 200 meV is present near the graphene point.

Electronic, magnetic and optical properties of MnPX (X = S, Se) monolayers with and without chalcogen defects: a first-principles study.

Based on density functional theory (DFT), we performed first-principles studies on the electronic structure, magnetic state and optical properties of two-dimensional (2D) transition-metal phosphorous trichalcogenides MnPX (X = S and Se). The calculated interlayer cleavage energies of the MnPX monolayers indicate the energetic possibility to be exfoliated from the bulk phase, with good dynamical stability confirmed by the absence of imaginary contributions in the phonon spectra. The MnPX monolayers are both Néel antiferromagnetic (AFM) semiconductors with direct band gaps falling into the visible optical spectrum.

Unoccupied electronic band structure of pentagonal Si nanoribbons on Ag(110).

Silicon nanoribbons - one dimensional silicon structures with a pentagonal atomic structure and mixed sp- and sp-hybridisation - grow on Ag(110) upon deposition of silicon. These nanostructures are viewed as promising candidates for modern day electronics as they are comprised of the same element as today's semiconductor devices. Even though they have been studied extensively over the last decade, only little is known about their unoccupied band structure which is important for possible future optoelectronics, semiconductor, and spintronics applications.

Dirac Electron Behavior for Spin-Up Electrons in Strongly Interacting Graphene on Ferromagnetic MnGe.

An elegant approach for the synthesis of graphene on the strong ferromagnetic (FM) material MnGe is proposed via intercalation of Mn in the graphene-Ge(111) interface. According to the density functional theory calculations, graphene in this strongly interacting system demonstrates the large exchange splitting of the graphene-derived π band. In this case, only spin-up electrons in graphene preserve the Dirac-electron-like character in the vicinity of the Fermi level and the K point, whereas such behavior is not detected for the spin-down electrons.

The graphene/n-Ge(110) interface: structure, doping, and electronic properties.

The implementation of graphene in semiconducting technology requires precise knowledge about the graphene-semiconductor interface. In our work the structure and electronic properties of the graphene/n-Ge(110) interface are investigated on the local (nm) and macro (from μm to mm) scales via a combination of different microscopic and spectroscopic surface science techniques accompanied by density functional theory calculations. The electronic structure of freestanding graphene remains almost completely intact in this system, with only a moderate n-doping indicating weak interaction between graphene and the Ge substrate.

Layer-by-Layer Decoupling of Twisted Graphene Sheets Epitaxially Grown on a Metal Substrate.

The electronic properties of graphene can be efficiently altered upon interaction with the underlying substrate resulting in a dramatic change of charge carrier behavior. Here, the evolution of the local electronic properties of epitaxial graphene on a metal upon the controlled formation of multilayers, which are produced by intercalation of atomic carbon in graphene/Ir(111), is investigated. Using scanning tunneling microscopy and Landau-level spectroscopy, it is shown that for a monolayer and bilayers with small-angle rotations, Landau levels are fully suppressed, indicating that the metal-graphene interaction is largely confined to the first graphene layer.