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The S vacancy at metal/ MoS 2 interface plays a much important role than the semiconductor itself. In this work, the influence of different configurations of S vacancy concentrations on the effective work function and band structure of the Au/ MoS 2 interface has been investigated systematically using first-principles calculations. The study specifically explores the effective work function of the Au/ MoS 2 interface, the deviation of interface effects from the vacuum work function, and the dipole moment caused by interface charge transfer. The results reveal that the electronic work function of Au/ MoS 2 increases with the increase in S vacancy concentration, but the rate of increase tends to slow down with higher S concentrations. The variation in the effective work function of the Au/ MoS 2 interface may be attributed to the presence of S vacancies and the exposure of Mo atoms. S vacancies lead to a reduction in the Schottky barrier, resulting in increased leakage current. The Fermi pinning caused by S vacancy concentration and location is also observed. The results obtained in this study can serve as a theoretical foundation for applications in electronic devices that rely on metal/ MoS 2 contact. [ABSTRACT FROM AUTHOR]

The unstable plume mode of hollow cathodes should be avoided in practical applications because it severely degrades the overall cathode lifetime. In this study, we investigate the spot-plume transition and plasma stability characteristics of an unused segmented lanthanum hexaboride emitter. The expansion of the unstable plume mode region is observed during a discharge experiment. Subsequently, the segmented emitter is retrieved, the inner surface of the emitter is observed, and the work function on the surface is measured at room temperature. The emitter surface exhibits color variations with oxygen and carbon detection. The downstream edge shows the original purple color and almost no degradation in the work function. The high temperature in this region promotes the desorption of carbon and oxygen. In the spot mode, this region mainly contributes to thermionic electron emission; therefore, the discharge voltage in the spot mode does not change during the discharge experiment. Carbon or carbide is detected in the middle of the axial direction on the emitter surface, where the surface temperature is not sufficiently high to desorb carbon during discharge. Based on the surface analysis results, the dominant substance in the region where carbon is detected was lanthanum carbide. An increase in the work function is indicated in the region, which appears to increase the plasma instability. According to previous studies, an increase in the work function results in a rise in the potential in the emitter, and an increase in the electron temperature in the outside plume region induces the plasma instability. Further investigation is needed to understand the mechanism connecting the rise in the work function and the rise in the electron temperature in the plume region. [ABSTRACT FROM AUTHOR]

The dependence of electron work function, Φ , on the thickness of Ti layers was investigated by making use of the Kelvin method under ambient conditions. Layers were produced by vacuum phase deposition and were analyzed by x-ray photoelectron spectroscopy and transmission electron microscopy. A quantum size effect was revealed finding work function to increase as the layer thickness, z, decreased below 4 nm. The extent of increase, Δ Φ , was understood in terms of a simple particle-in-a-box model arriving at the function Δ Φ = ℏ 2 π 2 / 2 m e z 2 . This equation being free of any adjustable parameter, consisting only of the Planck constant and electron mass, seems to be a reasonable first approximation. [ABSTRACT FROM AUTHOR]

Oxyhydrides have attracted attention as materials with various unique properties derived from lattice hydride ions (H−). However, their instability makes synthesis by conventional thermal synthesis methods difficult, so an appropriate synthesis strategy is required. Here, the mechanochemical synthesis of perovskite oxyhydrides BaREO2H (RE = Y, Sc) for catalyst applications is reported. The formation of BaYO2H is known to be thermodynamically unstable; however, a mechanochemical process that inevitably proceeds under non‐equilibrium conditions enables the synthesis of such a metastable oxyhydride material without any heat treatment. Furthermore, BaScO2H, which is typically obtained at very high temperatures (1000 °C) and pressure (>4 GPa), is successfully synthesized at room temperature by the mechanochemical method. The ammonia synthesis reaction over these oxyhydrides supporting Ru is significantly enhanced at low temperatures, and the ammonia synthesis rates are significantly higher than conventional oxide‐supported Ru catalysts. The mechanochemically synthesized BaREO2H has many anionic electrons with low work function at the site of H− vacancies, which enables strong electron donation to Ru and the storage of excess hydrogen adatoms from the Ru surface that results in high catalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] The sluggish kinetics and inferior stability of oxygen electrocatalyst in rechargeable zinc air battery (ZAB) hamper its industrialization. In this work, we activate cobalt telluride (CoTe) by introduction of metallic cobalt (Co) to modulate the work function to facilitate the electron transfer from Co to CoTe during oxygen catalysis; additionally, the three-dimensional porous carbon nanosheets (3DPC) are invited to reduce the resistance towards electrolyte/oxygen diffusion. Thereby, Co-CoTe@3DPC only demands 280 mV overpotential to reach 10 mA cm−2 under alkaline oxygen evolution reaction (OER) condition, relatively lower than commercial iridium oxides (IrO 2); besides, the operando electrochemical impedance spectroscopy (EIS) indicates a better resistance towards surface reconstruction than Co@3DPC leading to a superior stability. A Pt-like oxygen reduction reaction (ORR) performance, half-wave potential associated with kinetic current density, is achieved for Co-CoTe@3DPC. A maximum power density of 203 mW cm−2 is achieved and sustains for 800 h. Furthermore, the all-solid-state ZAB offers 97 mW cm−2. Theoretical calculation suggests that the incorporation of metallic Co to CoTe maintains the superb ORR activity and promotes the OER catalysis. [ABSTRACT FROM AUTHOR]

Multi-componentization can further improve the heating resistance of Cu–Ni–Al alloys, enabling them to withstand more demanding situations. Unfortunately, the limited researches have been done on the wear and corrosion resistance of the heat-resistant Cu–Ni–Al alloys, resulting in the lack of relevant evidence in the practical application. In this work, a comparative study of differential types of trace element, Si (the stronger enthalpy interaction element), Sn (the weaker enthalpy interaction element) Cr or Zr (grain boundary strengthening element), effects on microstructure, wear and corrosion resistance will be done, Furthermore, the effect of different trace elements on the surface electron work function and electrochemical behavior of Cu–Ni–Al alloys is reflected by SPM surface potential model. The results indicate that the precipitation of dual nano-phase and accelerated precipitation of γ′ phase can be realized through the addition of Si, Sn, Cr and Zr, in which the value of δγ-γ′ increase sharply after adding Si and it is not conducive to the preservation of cuboidal γ′ phase. The addition of Si, Cr and Zr can improve electron work function distribution and mechanical property, wear, and corrosion resistance of the alloys, in which Si is more conducive to the improvement of wear resistance and mechanical properties of the alloy, while the alloy with Cr and Zr shows the excellent corrosion resistance. The addition of Sn will weaken the enthalpy interaction of the alloy system, reduce the electron work function of the alloy, and have adverse effects on the wear and corrosion resistance of the alloy.

Considered patterns of formation of the nanostructural state of the surface layer of machine parts during friction under conditions of complex dynamic loading. The results of the complex assessment of the state of the surface layer of samples after friction continuous indentation and scanning methods indenter, an analysis of changes in the work function of the electron from the surface of the samples. Shown that during the friction of steel surfaces, an increase in transverse slippage contributes to the formation of a more uniform surface layer. This decreases its strength, wear resistance, and a more uniform surface microgeometry. This is accompanied by a decrease in the magnitude and spread of the electron work function over the surface. The relationship between the nanostructural state of a polished surface and roughness and reflectivity is presented. [ABSTRACT FROM AUTHOR]

The highly insulated solid discharge products in sodium‐oxygen (Na−O2) batteries induce large polarization and thus heavily threaten their cycle life. Controlment of discharge products taking efficient catalyst is a best way to solve this problem. Here, Mo‐doped BiVO4 as the catalyst produces large amounts of carrier, thus boosting the battery reaction and reducing the overpotential under the light assistance. Compared with the BiVO4 without Mo doping, the doped one has a lower recombination of photogenerated carriers, thus benefiting a large polarization suppression and Na−O2 batteries running for over 270 cycles under 3.65 V as well as a fine rate performance. Besides, Mo doping reduces the size of BiVO4, beneficial for the carrier transportation and more reactions due to the large specific surface area. Experiment combined with theoretical calculation shows that Mo doping is advantageous to enhancing catalytic activity of BiVO4 due to a lower work function for easier electron extraction, thus enhancing Na2O2 decomposition capability. This work undoubtedly inspires photocatalysts′ use for solving the insulated solid discharge products decomposition in metal‐O2 batteries and provides a guide for other photocatalysts possibilities. [ABSTRACT FROM AUTHOR]

Inverted organic light-emitting devices (OLEDs) have been aggressively developed because of their superiorities such as their high stability, low driving voltage, and low drop of brightness in display applications. The injection of electrons is a critical issue in inverted OLEDs because the ITO cathode has an overly high work function in injecting electrons into the emission layer from the cathode. We synthesized hexagonal wurtzite ZnO nanoparticles using different oxidizing agents for an efficient injection of electrons in the inverted OLEDs. Potassium hydroxide (KOH) and tetramethylammonium hydroxide pentahydrate (TMAH) were used as oxidizing agents for synthesizing ZnO nanoparticles. The band gap, surface defects, surface morphology, surface roughness, and electrical resistivity of the nanoparticles were investigated. The inverted devices with phosphorescent molecules were prepared using the synthesized nanoparticles. The inverted devices with ZnO nanoparticles using TMAH exhibited a lower driving voltage, lower leakage current, and higher maximum external quantum efficiency. The devices with TMAH-based ZnO nanoparticles exhibited the maximum external quantum efficiency of 19.1%. [ABSTRACT FROM AUTHOR]

Insulin and immunoglobulin therapy is commonly administered through injections that are invasive and painful. They cannot be taken orally because digestive enzymes break them down. To protect against enzymes, drug molecules may be "packed", which decreases interaction of the active surface of the molecule with the environment. Silica nanoparticles (SiO2) may be used to attach proteins like insulin or immunoglobulin for use in drug delivery. They are stable and biocompatible. Exposing SiO2 nanoparticles to UV radiation may control molecule–nanoparticle attachment because of their electrostatic interactions. This study demonstrates the influence of UV radiation of SiO2 nanoparticles on insulin and immunoglobulin molecule attachment. Alteration of the surface electric potential of SiO2 nanoparticles by UV radiation was determined using electron work function measurements. Influence of radiation on formation of molecule-nanoparticle complexes was assessed by spectrophotometry of their sedimentation rate in solution. Increasing UV exposure time negatively charges the surfaces of SiO2 nanoparticles. Insulin exhibits better adsorption with SiO2 nanoparticles compared to immunoglobulin, likely due to favourable conditions promoting attractive electrostatic interactions. Longer UV exposure weakens insulin adsorption but does not significantly affect immunoglobulin adsorption. [ABSTRACT FROM AUTHOR]

We examine thin film on a dielectric substrate (vacuum/Al/SiO2) in the stabilized jellium model and the Kohn–Sham method. We investigate surface and size effects on the effective potential and the electron work function, and analyze the spatial distributions of electrons and potentials. It is found that a dielectric environment generally leads to a decrease in the work function. The effect of dielectric confinement for the electron work function of the asymmetric metal-dielectric nanosandwiches is reduced only by the surface area weighted average value of the dielectric constants. This conclusion follows from the application of the Gauss theorem for a conducting sphere with an inhomogeneous dielectric coating. The flow of electrons from the dielectric face to the vacuum one due to the contact potential difference manifests itself in the appearance of an additional dipole between the left and right face within the spatial distributions of ions. This leads to the fact that in a vacuum the electrostatic and effective potentials change sign twice, as a result of which a potential barrier appears above the vacuum level. We introduced the position of an electron conduction band in the dielectric as the input parameter in the self-consistency procedure for one of the sandwich approximations. As it turned out, the barrier height depends only on the used local or non-local approximation of the exchange-correlation energy. The nontrivial origin and behavior of the calculated effective potential on the vacuum side of the film, as well as the reasons for it, are discussed. [ABSTRACT FROM AUTHOR]

In this paper, structural, electronic properties, optical spectra, stability, as well as the quantum efficiency of bulk, monolayer and two different stacking heterostructure configurations (XY2/XY2) of dichalcogenide compounds XY2 (where X = Mo or W and Y = S or Se) were performed using density functional technique. Our findings reveal the strong chemical bonds and high interlayer banding energy for MoSe2/WSe2 heterostructure of configuration-2, which confirms its stability and its feasibility for synthesizing. Besides, the elastic stiffness coefficients demonstrate all studied heterostructures are mechanically stable at ambient pressure, this means that the studied heterostructures are harder to separate their components, making them more durable and less reactive under certain conditions, especially MoSe2/WSe2 heterostructure-configuration 2. Otherwise, the electronic band structure highlights an indirect semiconductor behavior for bulk XY2. In contrast, a strong ionic bonding between the chalcogen and metal atoms leads to the electrons confinement in the direction perpendicular to the plane revealing direct semiconductor behavior for monolayers XY2 at Γ point. Besides, after combining two monolayers with different work functions the holes and electrons are accumulated in different layers, therefore indirect excitons have been observed for XY2/XY2 heterostructures (Γ → K). Furthermore, due to the presence of the type-II band alignment, the optical absorbance spectra proves that the absorbance is enhanced along both x and z directions for all investigated heterostructures. In addition, the MoSe2/WSe2 heterostructure of configuration-2, has about 65% of photons converted into usable electrical power, while 35% of photons are lost as heat and/or reflected. Finely, its high stability, its suitable forbidden band, its high visible light absorption, as well as its high quantum efficiency make the 2D Van der Waals MoSe2/WSe2 heterostructure-configuration-2 as new potential candidate for upcoming nano-electronic, photovoltaic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Electron transfer from a metal surface to a molecule is very important at the gas–surface interface, which can lead to electron-mediated energy transfer during molecular scattering from the surface, as evidenced by numerous state-to-state molecular beam experiments of NO and CO scattering from noble metal surfaces. However, it remains challenging to determine relevant charge-transfer states and their nonadiabatic couplings from first principles in such systems involving a continuum of metallic electronic states. In this work, we propose a pragmatic protocol for this purpose based on the constrained density functional theory (CDFT) approach. In particular, we discuss the influence of the charge partitioning algorithm used in CDFT to define the constraint property in molecule–metal systems. It is found that the widely used Bader charge analysis is adequate to define the physically sound CDFT diabatic states corresponding to a molecule with or without extra electron transferred from the metal. Numerical tests validate that the proposed CDFT scheme properly describes the electron transfer behaviors in several benchmark systems, namely, NO or CO interacting with Au(111) or Ag(111). The effects of the surface work function and the molecular electron affinity on electron transfer are discussed in detail by comparing the CDFT states of the four systems. This pragmatic CDFT protocol lays the foundation for constructing accurate global diabatic potential energy surfaces for these important systems and can be generalized to study other interfacial electron transfer related problems. [ABSTRACT FROM AUTHOR]

This article reports a study on the modification of bulk and Young's moduli of MoC carbide by partially substituting Mo with selected metallic elements, which influence the strengths and contributions of covalent, ionic, and metallic bond components to the overall atomic bonding of the carbide and thus its mechanical properties. Electron work function (EWF) analysis demonstrates that this parameter plays a promising role as an indicator similar to an encoded parameter with material "genetic" information for guiding the substitute selection. The higher the carbide's EWF, the higher are its bulk and Young's moduli. A substitute having a higher EWF generally enhances the covalent bonding at the expense of ionic bonding. The covalent bond plays a primary role in determining the carbide's strength, while the ionic bonding also contributes to the strength to some degree. A substitute having a higher EWF enhances the metallic bonding, which improves the carbide's strength as well, although such a contribution is minor. [ABSTRACT FROM AUTHOR]

Amorphous alloy is a popular choice for wastewater treatment because of its high active sites and high catalytic performance. It is different from the previous situation that the degradation performance of amorphous materials decreases first and then increases after crystallization. The degradation efficiency of Direct Yellow GR dye (DYGR) by Electro-Fenton (E-F) is gradually increases as the amorphous content of Fe41Co7Cr15Mo14C15B6Y2 amorphous alloy powder (MGs) is reduced in this work. The in-situ precipitation of (Fe, Cr)23(C, B)6 and Fe7C3 nanocrystals was discovered to decrease the electron work function (EWF) of the alloy powder, thus decreasing the amount of work needed to escape electrons and enhancing the electrocatalytic performance of the material. At the same time, the precipitation of (Fe, Cr)23(C, B)6 nanocrystals changed the chemical composition of the surface of MGs. After annealing, the Fe2+ concentration was higher than before regression, and the chemical potential energy between Fe2+ and Fe3+ was greater, thus facilitating the formation of ∙OH. This research offers novel perspectives on the utilization of nanocrystals in the management of amorphous alloy wastewater.

A numerical simulation of an intense thermionic emission of electrons from the cathode into the air medium in an electrode system has been performed with regard for the possible changes in the voltage across the electrodes and in the electronic work function of the cathode. Spatial distributions of the electrons, the electron energy, the ions, the electric-field strength, and the concentration of the atomic oxygen in the air medium were constructed with the use of a simplified set of kinetic reactions. A possibility of using the thermionic emission of electrons from a cathode for the cooling of the members of flying vehicles with the aim to proof them against heat loads was demonstrated. The numerical calculations have shown that the thermionic emission of electrons from the cathode in a system of electrodes with no protective resistor at a high pressure does not provide a cooling of the system. [ABSTRACT FROM AUTHOR]

In order to explore the possibility of CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayers as high‐performance gas sensors, the electronic properties and gas sensing performance of CH4 ${{{\rm C}{\rm H}}_{4}}$ , CO ${{\rm C}{\rm O}}$ , CO2 ${{{\rm C}{\rm O}}_{2}}$ , NO ${{\rm N}{\rm O}}$ , H2S ${{{\rm H}}_{2}{\rm S}}$ and Cl2 ${{{\rm C}{\rm l}}_{2}}$ gas molecules adsorbed on CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayers were investigated using a first‐principles approach. It was found that CH4 ${{{\rm C}{\rm H}}_{4}}$ , CO ${{\rm C}{\rm O}}$ and CO2 ${{{\rm C}{\rm O}}_{2}}$ had a weak chemisorption effect on the CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayer, while the physisorption of H2S ${{{\rm H}}_{2}{\rm S}}$ effectively altered the electronic properties and the work function of the CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayer. Compared with other gases, the CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayer has relatively high sensitivity to NO ${{\rm N}{\rm O}}$ , H2S ${{{\rm H}}_{2}{\rm S}}$ and Cl2 ${{{\rm C}{\rm l}}_{2}}$ , and the band gap of the system after adsorption changes significantly compared with the intrinsic CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayer, and the characteristics of the work function can effectively distinguish various gases. The results indicate that the CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayer has the ability to detect NO ${{\rm N}{\rm O}}$ , H2S ${{{\rm H}}_{2}{\rm S}}$ and Cl2 ${{{\rm C}{\rm l}}_{2}}$ gases with high sensitivity, especially for Cl2 ${{{\rm C}{\rm l}}_{2}}$ , and provide a theoretical basis for the development of CdS2 ${{{\rm C}{\rm d}{\rm S}}_{2}}$ monolayers for potential applications as gas sensors or scavengers for NO ${{\rm N}{\rm O}}$ , H2S ${{{\rm H}}_{2}{\rm S}}$ and Cl2 ${{{\rm C}{\rm l}}_{2}}$. [ABSTRACT FROM AUTHOR]

Structural optimization promotes water sterilization by low-voltage pulsed electric field. [Display omitted] • Cu 7 S 4 nanowire coated with N -doped carbon film is beneficial to the anchoring of Ag, and the loaded silver particles enhance the adsorption of O 2. • The successful coating of N -doped carbon layer and Ag particles improved the poor durability and conductivity of Cu 7 S 4. • The work function and electron difference density of different kinds of N -doped Cu 7 S 4 @NC@Ag demonstrate the direction of interface carrier transport. • The removal efficiency can still reach 99% after 8 h of continuous treatment at 6 V and 1000 mL min−1 flow rate. There are many methods of water disinfection, and how to realize low energy consumption, high efficiency and safety sterilization has always been a research hotspot. In this work, Cu 7 S 4 nanowires were grown on copper foam, and coated with N -doped carbon layer and Ag particles, which not only improved the conductivity and local field enhancement regions of the material, but also improved the durability and mechanical stability of Cu 7 S 4. DFT (Density functional theory) calculation shows that different kinds of N doping make the electron difference density and work function of the surrounding C different, which leads to high carrier transport capacity at the interface, and Ag anchored in N -doped carbon films can adsorb O 2. The band gap of the material is 2.12 eV, and the material has the potential to generate superoxide anion under energy excitation. Under the condition of 6 V voltage and 1000 mL min−1 water flow rate, the long-term water filtration sterilization of high-concentration bacteria can be realized, and the removal efficiency can still reach 99% after 8 h continuous treatment. This work has great application prospects for the purification of highly polluted water in the future. [ABSTRACT FROM AUTHOR]

Using XPS, the electron work function values on the surface of glassy carbon coatings of graphite samples, after an extended stay on a board of the ISS in open space conditions, were investigated. The results were compared with the characteristics of glassy carbon coatings of samples left on the ground for the same period. It was found that the electron work function does not change significantly, and this proves the possibilities for the successful application of these coatings, obtained by original Bulgarian technology, for space experiments on the board of satellites for measuring electric fields in the ionospheric-magnetospheric plasma. The minimal observed variations in the values of the electron work function are explained by small differences in the content of traces of different chemical elements on the surface of the coatings. It has been established that glassy carbon coatings have stable characteristics after a long stay in space, despite the small fluctuations in the values of the electron work function. The results show that glassy carbon coatings are chemically and mechanically stable. The results from this original technological experiment are unique for the development of sensitive elements, such as sensors for measuring weak electric fields in cosmic plasma. [ABSTRACT FROM AUTHOR]

The adsorption and reactions of water with surfaces is of immense importance in catalysis and corrosion. Charge transfer of ion scattering is sensitive to changes of work function and electronic structure caused by adsorption of water on a surface. In this work, as the model systems of metals and semiconductors the water adsorbed copper and silicon surfaces have been chosen and the research progress of charge transfer of the negative and positive ion scattering in our group were reviewed. [ABSTRACT FROM AUTHOR]

There is a widespread interest in time-resolved electron spectroscopies such as ultrafast electron diffraction, ultrafast electron microscopy, and ultrafast electron energy loss spectroscopy. These techniques require pulsed electron beams with both high current and brightness. LaB6 is commonly used as a thermionic emitter because of its low work function and high electron yield. However, its use as a pulsed photocathode has not been widely explored. Here, we present measurements of the electron yield from a LaB6 filament exposed to 392 nm UV ultrafast laser pulses under a wide range of filament temperatures. We find that sample heating strongly enhances photoelectron yield, an effect known as thermionically enhanced photoemission. However, it also creates potentially undesirable, continuous thermionic background. We conclude that the ideal optimal operating conditions strongly depend on the type of measurement and require defining and quantifying an appropriate figure of merit. [ABSTRACT FROM AUTHOR]

The presented work discusses an analytical setup that is capable of detecting surface alterations of aerosol nanoparticles. Utilizing the photoelectric effect, Aerosol Photoemission Spectroscopy (APES) is introduced as an online technique that determines the electron work function (eWF) of an aerosol particle material at ambient pressure. Beyond the detailed presentation of the experimental setup, the limitations and possibilities of APES are discussed with regard to metal oxide formation in technical and ultra-clean process gases. Deploying APES as an analytical tool operating at atmospheric pressure, the interaction of oxidizing and reducing gas species becomes observable for various metallic nanoparticles. As shown by APES measurements, even nitrogen with a purity of 7.0 (99.99999%) enables oxide formation when a metallic particle material is processed as an aerosol. Contrary to this, ultra-clean process gases, such as nitrogen with 10−13 ppm residual oxygen, allow the synthesis of oxide-free particles. In addition to the influence of oxygen and hydrogen on mono-metallic particles, this work includes the first results of the surface properties of so called "hetero-aggregates," nanoparticles that consist of two metals. Binary particles, such as CuNi or PtFe, exhibit varying alloying and oxidation behaviors, depending on the process gas used, which can be evaluated based on the development of the eWF during particle formation. Copyright © 2023 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

In order to repair a failed AlSiY coating on aeroengine turbine components, the AlSiY coating was stripped using a nitric acid-based removal reagent. The homogeneity of chemical stripping was evaluated and the stripping mechanism was clarified using first-principles calculations. The effects of hydrofluoric acid (HF) and chromium trioxide (CrO3) on the homogeneity of chemical stripping were investigated by calculating the electronic work functions (EWFs) of the stripped surfaces. The results showed that the stripped surfaces of the AlSiY coating exhibited a serrated appearance when it was etched by a single nitric acid solution, indicating severely inhomogeneous stripping. With the addition of HF and/or CrO3, the homogeneity of chemical stripping could be greatly improved, which was attributed to the increased EWF of the (200) surface and the decreased EWF of the (110) surface, causing the corrosion cathode to transition from the (110) surface to the (200) surface. The HF+CrO3+HNO3 mixed reagent was the optimal combination for the uniform stripping of the AlSiY coating, while the inner layer was not broken. The Al atoms on the surface could be preferentially removed due to the strong bonding with acid ions. The research method proposed in the present work will provide a new means to design chemical removal reagents. [ABSTRACT FROM AUTHOR]

In this work, the surface energy of titanium crystal faces was estimated using the electron-statistical method, taking into account the contributions of the dispersion, polarization, and oscillation corrections. Using an analytical relationship, the values of the work function of close-packed faces of polymorphic modifications of titanium are calculated from the values of the surface energy of single crystals taking into account the crystal structure. The influence of polymorphic transformation and temperature on the anisotropy of the studied properties is shown. Based on the values of the surface and interfacial energies, which consist of the average configurational energy and the energy of chemical interaction of two parts of the metal, the cohesive energy of - and -titanium is estimated and its dependence on temperature is shown. On the example of tungsten-titanium and molybdenum-titanium systems, the fundamental possibility of calculating the change in the work function depending on the concentration of the surface-active component in bimetallic systems is shown, which makes it possible to predict the service life of the material.

An accurate atomistic treatment of aqueous solid–liquid interfaces necessitates the explicit description of interfacial water ideally via ab initio molecular dynamics simulations. Many applications, however, still rely on static interfacial water models, e.g., for the computation of (electro)chemical reaction barriers and focus on a single, prototypical structure. In this work, we systematically study the relation between density functional theory-derived static and dynamic interfacial water models with specific focus on the water–Pt(111) interface. We first introduce a general construction protocol for static 2D water layers on any substrate, which we apply to the low index surfaces of Pt. Subsequently, we compare these with structures from a broad selection of reference works based on the Smooth Overlap of Atomic Positions descriptor. The analysis reveals some structural overlap between static and dynamic water ensembles; however, static structures tend to overemphasize the in-plane hydrogen bonding network. This feature is especially pronounced for the widely used low-temperature hexagonal ice-like structure. In addition, a complex relation between structure, work function, and adsorption energy is observed, which suggests that the concentration on single, static water models might introduce systematic biases that are likely reduced by averaging over consistently created structural ensembles, as introduced here. [ABSTRACT FROM AUTHOR]

Hafnium (Hf) has been used as a cathode material for thermionic emission in high temperature environments for a long time. However, the effect of grain boundaries (GBs) on its work function has not been reported. In this work, by using first-principles calculations, we find that the introduction of GBs would reduce the work function of Hf surface as compared with that of the perfect crystal, and by increasing the distance between two grain boundaries, the work function converges gradually to the value of monocrystalline Hf. By analyzing the surface atomic structure and charge density distribution, we find that the reduced work function of GB-containing structures originates from the increase of atomic distance and the changes of atomic coordination environments at the GB region, which results in redistribution of electrons and enhances the electronic density of states at the Fermi level. [ABSTRACT FROM AUTHOR]

In the present work, the adsorption of some simple organic sulfur gases (CS2, OCS, and CH3SH) on the g-C3N4 was studied using periodic and non-periodic density functional theory (DFT). PBE-D3/DNP and B3LYP-D3/6-31G(d) levels of theory were employed for periodic and non-periodic calculations, respectively. The calculated CS2, OCS, and CH3SH adsorption energies were obtained to be −4.35, −5.82, and −8.58 Kcal/mol. The interactions of simple organic sulfur gases with g-C3N4 were characterized by NBO second-order perturbation theory and quantum theory of atom in molecule (QTAIM). The bandgap energies and work function of g-C3N4 and its complexes with simple organic sulfur gases were extracted from their band structures. The CS2 and OCS adsorptions didn't significantly alter the bandgap and work function of g-C3N4. Therefore, g-C3N4 is not a proper sensor for detecting CS2 and OCS. The bandgap and work function of g-C3N4 were averagely changed by 18% and 2.7%, respectively, after CH3SH adsorption. Accordingly, g-C3N4 may use as a suitable sensor for detecting CH3SH based on electronic conductivity and work function. [ABSTRACT FROM AUTHOR]

Changes in electron work function (EWF) during the separation of Si(100) single-crystal silicon wafers into smaller samples (scribing operation) have been studied by the method of kinetic curves of EWF. The observed effect can be attributed to the sorption of water vapor on the Si(100) surface. The Helmholtz formula has been applied to estimate the amount of water absorbed by the samples, causing a change in the EWF. To determine the localization of sorbed water, we have used the method of layer-by-layer etching of the surface of Si(100) samples using low-temperature SF6-plasma. It has been shown that with a decrease in the size (area) of the samples, the size effect of the EWF takes place. For a whole plate (with an area of 80 cm2) is characterized by the EWF value close to its reference value ( eV), while for small samples (~1 cm2), this value decreases to 4.5 eV, which indicates a significant water content in the samples (~0.3 × 1015 molecules cm–2). The data on sample etching by plasma have showed that water is unevenly distributed over the thickness of the sample, and is mainly concentrated in its deeper layers, not changed by mechanical processing (grinding and polishing). The results obtained are consistent with the theory of the secondary structure of a crystal (SSC), according to which crystalline solids have regular gaps ("T-space") with a size of "1 atomic layer," in which impurity transfer processes occur. Apparently, chemisorption of water takes place in the micropores of the T-space, which leads to size effects on Si(100). [ABSTRACT FROM AUTHOR]

Materials descriptors with multivariate, multiphase, and multiscale of a complex system have been treated as the remarkable materials genome, addressing the composition–processing–structure–property–performance (CPSPP) relationships during the development of advanced materials. With the aid of high‐performance computations, big data, and artificial intelligence technologies, it is still a challenge to derive an explainable machine learning (ML) model to reveal the underlying CPSPP relationship, especially, under the extreme conditions. This work supports a smart strategy to derive an explainable model of composition–property–performance relationships via a hybrid data‐driven and knowledge‐enabled model, and designing superhard high‐entropy diboride ceramics (HEBs) with a cost‐effective approach. Five dominate features and optimal model were screened out from 149 features and nine algorithms by ML and validated in first‐principles calculations. From Shapley additive explanations (SHAP) and electronic bottom layer, the predicted hardness increases with the improved mean electronegativity and electron work function (EWF) and decreases with growing average d valence electrons of composition. The 14 undeveloped potential superhard HEBs candidates via ML are further validated by first‐principles calculations. Moreover, this EWF‐ML model not only has better capability to distinguish the differences of solutes in same group of periodic table but is also a more effective method for material design than that of valence electron concentration. [ABSTRACT FROM AUTHOR]

Coupled electron/ion transport is a decisive feature of Li plating/stripping, wherein the compatibility of electron/ion transport rates determines the morphology of deposited Li. Local Li+ hotspots form due to inhomogeneous interfacial charge transfer and lead to uncontrolled Li deposition, which decreases the Li utilization rate and safety of Li metal anodes. Herein, we report a method to obtain dendrite‐free Li metal anodes by driving electron pumping and accumulating and boosting Li ion diffusion by tuning the work function of a carbon host using cobalt‐containing catalysts. The results reveal that increasing the work function provides an electron deviation from C to Co, and electron‐rich Co shows favorable binding to Li+. The Co catalysts boost Li+ diffusion on the carbon fiber scaffolds without local aggregation by reducing the Li+ migration barrier. The as‐obtained dendrite‐free Li metal anode exhibits a Coulombic efficiency of 99.0 %, a cycle life of over 2000 h, a Li utilization rate of 50 %, and a capacity retention of 83.4 % after 130 cycles in pouch cells at a negative/positive capacity ratio of 2.5. These findings provide a novel strategy to stabilize Li metal by regulating the work function of materials using electrocatalysts. [ABSTRACT FROM AUTHOR]

The localized corrosion induced by different kinds of inclusions in low‐nickel stainless steel is studied through immersion tests and first‐principles calculations. The galvanic corrosion between the steel matrix and different kinds of inclusions occurs in the corrosive environment due to the difference in the electron work function of the steel matrix and inclusions. The electron work function of MnS, CeS, and Ce‐O‐S is smaller than that of the steel matrix, thus, these inclusions first dissolve as the anode. However, the electron work function of cerium‐containing oxides is bigger than that of the steel matrix, and the steel matrix dissolves prior to cerium‐containing oxides. The order of the volume expansion rate of pits induced by inclusions is CeS > Si‐Mn(‐Al)‐O > MnS > Ce‐C‐O‐S > Ce‐Si‐Mn(‐Al)‐O > Ce‐O‐S. For cerium‐containing inclusions, the electron work function of inclusions increases with the increase of the O/Ce ratio and the S/Ce ratio of inclusions. The order of the electron work function of cerium‐containing inclusions is cerium oxides > cerium sulfides > cerium oxysulfide. [ABSTRACT FROM AUTHOR]

To improve the surface properties of austenitic stainless steels, a thick S-phase layer was prepared by using a novel critical temperature nitriding (CTN) process. The properties of the thick S-phase layer were optimized by controlling the process parameters. The microstructures and phase compositions of CTN-treated layers were characterized by the optical microscope, scanning electron microscope and X-ray diffraction, respectively. The surface properties, including corrosion and wear resistance, were systematically investigated by the electrochemical workstation, micro-hardness tester and ball-on-disk tribometer, respectively. The results showed that a thick S-phase layer with a thickness of 18 to 25 μm can be fabricated in a short time by critical temperature nitriding, which represented higher efficiency than conventional low-temperature nitriding. Although the most top surfaces of CTN-treated layers contain massive iron nitrides, there are no precipitates in the inner nitrided layer. The electronic work function calculated by first-principles method has confirmed that those iron nitrides had a slight influence on the corrosion resistance of nitrided layers. The optimized CTN-treated layer exhibited a comparable corrosion resistance and wear resistance as the low-temperature nitrided layer. The CTN process is considered a potentially highly efficient surface modification method for austenitic stainless steels. [ABSTRACT FROM AUTHOR]

Doped hole (respectively electron) transport layers [HTLs (respectively ETLs)] are commonly used in evaporated organic devices to achieve high work function hole contact (respectively low work function electron contact) in organic LEDs to inject large current, in solar cells to increase the open circuit voltage, and in photodetectors to minimize the dark current. However, optimization of the HTL thickness results from a delicate trade-off. Indeed, on the one hand, to minimize the impact of HTLs on light propagation and series resistance effects, it is commonly admitted that HTLs must be kept as thin as possible. In this work, a model, validated by drift and diffusion simulations, has shown that, depending of the doping level, a minimum thickness between 10 and 20 nm was needed to prevent the transport layer work function from degradation due to field effects. Experiments have been performed on template p-only devices featuring a single HTL of various thicknesses and doping, confirming the validity of the model. Finally, simulations have been performed on a p-i-n device featuring both HTL and ETL. These results constitute precious indications for the design of efficient evaporated organic LEDs, solar cells, or photodetectors. [ABSTRACT FROM AUTHOR]

The effects of alloy surface composition and pre-adsorbed oxygen on the behaviors of H2O over Ni–Cr binary alloy surfaces were investigated by using the first-principles method. The surface energies and work functions for a series of Ni–Cr (111) alloy surfaces with different Cr concentrations were addressed to track the surface reactivities. An enhancement effect on the surface reactivity from Cr doping in the top-surface layer (TSL) of nickel substrates was identified. The locations of Cr in the TSL dramatically promoted exothermic adsorption of H2O and its decomposed products, including OH, O, and H. The calculated potential dissociation pathways further demonstrated that the successive dissociation of H2O molecules was substantially triggered in the presence of Cr doping in the TSL. By contrast, the Cr doping in the sub-surface layer hindered the dehydrogenation of H2O with a relatively higher energy barrier for OH dissociation. Moreover, with pre-adsorbed oxygen atoms closer to Cr, the first elementary step of H2O dissociation was easily fostered, whereas the OH dissociation was hindered. The Cr doping and O pre-adsorption accelerated the dissociation of H2O, which plays a critical role in the initial oxidation of nickel-based alloys in water- or oxygen-bearing environments. [ABSTRACT FROM AUTHOR]

We study the problem of chasing convex bodies online: given a sequence of convex bodies Kt ⊆ Rd the algorithm must respond with points xt ∈ Kt in an online fashion (i.e., xt is chosen before Kt+1 is revealed). The objective is to minimize the sum of distances between successive points in this sequence. Bubeck et al. (STOC 2019) gave a 2O(d)-competitive algorithm for this problem.We give an algorithm that is O(min(d,√d logT ))- competitive for any sequence of length T [ABSTRACT FROM AUTHOR]

Lanthanum hexaboride ( LaB 6) hollow cathodes have demonstrated a capability for long life operation, which is critical to many space exploration missions. Thermal characterization of LaB 6 hollow cathodes has revealed lower than expected electron emitter temperatures when the cathode reaches a steady state. This phenomenon is observed at discharge currents ranging from 5 to 35 A and xenon mass flow rates of 5–25 SCCM in cathodes with three different orifice diameters. Thus, the currently accepted value of the work function for polycrystalline LaB 6 , 2.67 eV, does not describe well the emission characteristics of LaB 6 hollow cathodes operating with internal gas discharges at a steady state. We use empirically measured temperatures combined with a model of the hollow cathode emitter and xenon discharge to estimate the value of the work function, yielding a value ranging from 2.1 to 2.44 eV. This lower work function value implies that LaB 6 hollow cathodes are expected to have even longer lifetimes than previously anticipated, further establishing them as a more suited alternative to other conventional cathode technologies for the task of long duration travel. Direct measurements of the work function as a function of depth on a hollow cathode emitter using x-ray photoelectron spectroscopy and ion beam milling indicate that the work function decreases with depth. We postulate several mechanisms that could explain the observed work function enhancement. Altogether, our results have important implications to the design, study approach, and operation of LaB 6 cathodes and potentially other cathodes with hollow configuration. Finally, our work opens the question of why the work function is reduced upon interaction with Xe plasma. [ABSTRACT FROM AUTHOR]

Self-heating thermionic hollow cathodes are essential components in modern plasma thrusters. To fully understand their operation, three interdependent physical domains must be considered: plasma discharge physics, thermal response of the cathode structure, and chemical evolution of plasma exposed surfaces. In this work, we develop the first self-consistently coupled plasma–thermal–chemical simulation platform for hollow cathode operation using lanthanum hexaboride (LaB 6) and Xe and study its performance against our experimentally determined temperature measurements. Results show that the customary assumptions of single-step resonant neutralization and full energy accommodation in ion-surface collisions fail to reproduce our empirical observations. We propose a two-step neutralization mechanism that consists of resonant neutralization to the first excited state of xenon followed by Auger de-excitation to the ground state, along with system specific accommodation factors. In this way, the agreement between the results of the simulations and experiments was achieved. These fundamental processes could govern neutralization in other cathode technologies where low work function emitters are employed and should therefore be accounted for in physical models. In addition, the new simulation platform allows us to better estimate the equilibrium work function of LaB 6 hollow cathode emitters. In the cathode studied here, we found that the effective work function is 2.25 eV, which is significantly lower than previous estimates, and leads to better than expected cathode material performance with important implications for space missions. [ABSTRACT FROM AUTHOR]

[Display omitted] The capacitance of the electrical double layer was measured in situ on a renewable Pb electrode in solutions of Bu 4 NClO 4 in propylene carbonate (PC). The results and published data were analyzed using correlational relationships between the zero charge potentials (E σ=0) of Hg, Pb, Sn, and Ga electrodes in solutions of surface-inactive electrolytes in PC, acetonitrile, and water on the one hand and the electron work functions of these metals (W e) on the other hand. It was concluded that Pb electrodes interacted weakly with the molecules of these solvents. [ABSTRACT FROM AUTHOR]

A simple expression for the Gamow factor is obtained using a second-order curvature-corrected tunneling potential. Our results show that it approximates accurately the "exact-WKB" transmission coefficient obtained by numerically integrating over the tunneling region to obtain the Gamow factor. The average difference in current density using the respective transmission coefficients is about 1.5 % , across a range of work functions ϕ ∈ [ 3 − 5.5 ] eV, Fermi energy E F ∈ [ 5 − 10 ] eV, local electric fields E l ∈ [ 3 − 9 ] V/nm, and radius of curvature R ≥ 5 nm. An easy-to-use correction factor λ P is also provided to approximately map the "exact-WKB" current density to the "exact" current density in terms of E F / ϕ. The average error on using λ P is found to be around 3.5 %. This is a vast improvement over the average error of 15 % when λ P = 1. Finally, an analytical expression for the curvature-corrected current density is obtained using the Gamow factor. It is found to compare well with the "exact-WKB" current density even at small values of local electric field and the radius of curvature. [ABSTRACT FROM AUTHOR]

The interface of Pt/TiO2 plays an essential role in device engineering and chemical reactions. Here, we report the electrostatic potential distribution of a Pt/TiO2 interface by electron holography. The decrease in the electrostatic potential exists at TiO2 in the vicinity of the interface, indicating the presence of negative charge due to electron transfer from TiO2 and Pt. The decrease in the electrostatic potential can be understood in the difference in work functions between Pt and TiO2. This study reveals the interplay between Pt and TiO2 and the usefulness of electron holography for probing the potential in nanoscale interfaces. [ABSTRACT FROM AUTHOR]

A high-strength and anti-intergranular corrosion (IGC) Al-6.8Zn-2.2 Mg-Sc-Zr alloy (AS alloy) was designed, and the effects of Sc addition and Cu removal on the microstructure, mechanical properties and corrosion behavior were systematically investigated. Based on transmission electron microscopy (TEM) and Kelvin probe force microscopy (KPFM) techniques, the underlying causes of IGC and exfoliation corrosion (EXCO) of the AS alloy were investigated, and the corrosion mechanism of AS alloy was finally obtained. The AS alloy exhibits excellent mechanical properties with a tensile strength of 601 MPa in the peak-ageing condition at 120 °C, which comes from the pinning effect of Al3(Sc, Zr) dispersions. Moreover, AS alloys of T6 and T74 conditions show outstanding IGC and EXCO resistance. On the one hand, the fine, near-ellipsoidal grains in AS alloy alleviate the peeling stress caused by IGC products by blocking the formation of wedge-shaped gaps along GBs, which then bring about improved EXCO resistance. On the other hand, the removal of Cu from the traditional Al-Zn-Mg-Cu alloy avoids the segregation of Cu into GBs and thereafter reduces the fluctuations of the potential and the electron work function (EWF) across the GBs; the addition of Sc induces the high fraction of LAGBs and thus weakens the solutes' segregation at GBs, which can be beneficial for smoothing the fluctuation of corrosion potential (Ecorr) to enhance the IGC resistance.

The electronic states' changes on the surface of the W(110) single crystal strained due to plastic bending are studied by the method of plasmon spectroscopy after thermal, thermochemical and ion treatments in comparison with those of analogous unstrained tungsten single crystal. The relative changes of the interplanar spaces, the concentration of the conduction electrons involved in plasma oscillations, as well as work function for electrons are calculated based on the plasmons' energy shifts. As established, the macroscopic bending of the W(110) single crystal leads to a decrease in the work function from its convex surface, which undergoes tensile deformation. The maximal difference in the work functions for unstrained and strained single crystals is observed after all sequentially used thermal, thermochemical and ion treatments and is of 0.2 eV. The obtained results are important for the practical application of thermionic energy converters with nonplanar electrodes. [ABSTRACT FROM AUTHOR]

In organic electronics, conjugated conductive polymers are most widely used. The scope of their application is currently very wide. Non-conjugated polymers are used much less in electronics and are usually used as insulation materials or materials for capacitors. However, the potential of non-conjugated polymers is much wider, due to the fact that new electronic materials with unique electronic properties can be created on the basis of non-conjugated polymers, as well as other inorganic dielectrics. This article demonstrates the possibilities of creating electrically conductive materials with unique electronic parameters based on non-conjugated polymers. The results of the study of the sensory properties of humidity are given as examples of the practical application of the structure. The abnormal electronic properties are realized along the interface of two polymer dielectrics with functional polar groups. The submicron films of polydiphenylenephthalide were used as a dielectric. It is shown that a quasi-two-dimensional electronic structure with abnormally large values of conductivity and mobility of charge carriers occurs along the interface. These structures are often called quasi-two-dimensional electron gas (Q2DEG). This article describes the manufacturing processes of multielectrode devices. Polymer films are deposited via the spin-coating method with polymer solutions in cyclohexanone. The metal electrodes were manufactured through thermal deposition in a vacuum. Three types of metal electrodes made of aluminum, copper and chromium were used. The influence of the electron work function of contacting metals on the electronic parameters of the structure was studied. It was established that the work function decrease leads to an increase in the conductivity and mobility of charge carriers. The charge carrier parameters were estimated based on the analysis of the current-voltage characteristics within the space-charge-limited current technique. The Richardson-Schottky thermionic emission model was used to evaluate values a potential barrier at metal/organic interfaces. It was established that the change in ambient humidity strongly affects the electronic transport properties along the polymer/polymer interface. It is demonstrated that the increase in conductivity with an increase in humidity occurs due to an increase in the mobility of charge carriers and a decrease in the height of the potential barrier at the three-dimensional metal contact with two-dimensional polymer interface. The potential barrier between the electrode and the bulk of the polymer film is significantly higher than between the electrode and the quasi-two-dimensional polymer structure. [ABSTRACT FROM AUTHOR]

The formation of a cellular hierarchically organized NiO film on a carbon paper substrate under hydrothermal conditions using triethanolamine as a base has been studied. The thermal behavior of the carbon paper substrate with the applied semi-product shell was studied using synchronous thermal analysis (TGA/DSC) and it was demonstrated that such modification of the material surface leads to a noticeable increase in its thermal stability. Using scanning electron microscopy (SEM), it was shown that the NiO film grown on the carbon fiber surface is characterized by a complex cellular morphology, organized by partially layered individual nanosheets of about 4–5 nm thickness and lateral dimensions up to 1–2 μm, some edges and folds of which are located vertically relative to the carbon fiber surface. The surface of the obtained material was also examined using atomic force microscopy (AFM), and the electronic work function of the oxide shell surface was evaluated using the Kelvin probe force microscopy (KPFM) method. The electrochemical parameters of the obtained flexible NiO/CP electrode were analyzed: the dependence of the specific capacitance on the current density was determined and the stability of the material during cycling was studied, which showed that the proposed approach is promising for manufacturing hierarchically organized electrodes for flexible supercapacitors. [ABSTRACT FROM AUTHOR]

The prediction of band edge potentials in photocatalytic materials is an important but challenging task. In contrast, bandgaps can be easily determined through absorption spectra. Here, we present two simple theoretical approaches for the determination of band edge potentials which are based on the electron negativity and work function of each constituent atom. We use these approaches to determine band edge potentials in semiconducting metallic oxides and sulfides, such as titanium dioxide (TiO2), chalcopyrite (CuFeS2), pyrite (FeS2), covellite (CuS), and chalcocite (Cu2S) with respect to an absolute scale (eV) and an electrochemical scale (V). Until now, there is little information on iron and copper sulfides referring to these thermodynamic parameters. TiO2 (Titania p25) was used as reference semiconductor to validate the calculation procedures using experimental values by X-ray diffraction analysis (XRD), diffuse reflectance spectrometry (DRS), and electron paramagnetic resonance spectroscopy (EPR). The production of key chemical species such as reactive oxygen species (ROS) and reactive sulfur species (RSS) has been theoretically and experimentally determined by EPR. [ABSTRACT FROM AUTHOR]

We examine thin film on a dielectric substrate (vacuum/Al/SiO2) in the stabilized jelly model. We investigate the surface and size effects on the effective potential and the electron work function for the weak quantization regime. We find that a dielectric environment generally leads to the decrease of the work function. We introduce the position of a conduction band for the dielectric as the input parameter in the self-consistency procedure. The effect of dielectric confinement for the energy characteristics of the asymmetric metal--dielectric sandwiches is reduced to only by the surface-area weighted average value of the dielectric constants. This conclusion follows from the application of the Gauss theorem for a conducting sphere with an inhomogeneous dielectric coating. The flow of electrons from the dielectric face to the vacuum one due to the contact-potential difference manifests itself in the appearance of a potential barrier above the vacuum level or positive values of the effective potential. The barrier height depends on the used local or non-local approximation of the exchange--correlation energy. The nontrivial origin and behaviour of the calculated effective potential on the vacuum side of the film, as well as the reasons for it, are discussed. In the focus of our representations, we analyse the recent results of measurements of the contact-potential difference depending on the number of Si atoms deposited on the free face of ytterbium nanofilms on the Si(111) substrates. Comparison and discrepancies between our self-consistent calculations for simple metals and these experiments are discussed. [ABSTRACT FROM AUTHOR]

Featured Application: Electrochromic devices, such as smart windows. The goal of this work was the synthesis study of the [WO2(C5H7O2)2] complex and its application as a precursor for the growth of WO3 films in hydrothermal conditions, as well as evaluating the microstructural features and electrochromic properties of the formed materials. Dioxotungsten acetylacetonate was synthesized in an aqueous medium and purified. It was found that during hydrothermal treatment of the alcohol solution of the complex, acetylacetonate ligands undergo partial destructive substitution by alkoxyl groups, intensifying at temperatures above 140 °C. Considering these data and using a [WO2(C5H7O2)2] solution, WO3 films were grown on glass and glass/ITO substrates. The resulting films had different microstructures according to scanning electron microscopy (SEM) and atomic force microscopy (AFM): the former consisted of submicron spheres (~500 nm), distinct nanoparticles (60–160 nm), and submicron- and micron-sized ridges, while the latter consisted of 1D structures (length 350 ± 25 nm, width 110 ± 25 nm). Using Kelvin probe force microscopy (KPFM), the electron work function was determined for the film on glass/ITO substrate (4.77 eV). It was found that the electrochemical coloration process of the obtained WO3 film can proceed in two stages, and the optical contrast is about 17.5% (at the wavelengths of 600–1100 nm). The results obtained show the prospects of applying the proposed approach to obtaining WO3 electrochromic films with a hierarchical microstructure with the hydrothermal method using the [WO2(C5H7O2)2] complex as a precursor. [ABSTRACT FROM AUTHOR]

Reasonable regulation of nonmetallic inclusions in steel can significantly improve its strength, toughness, and corrosion resistance. In this paper, EH420 marine steel was treated with Mg, Ce, and Mg-Ce to modify the inclusions. The effects of different treatments on the morphology, composition, size distribution, induced intragranular ferrite (IGF) nucleation, and pitting resistance of inclusions were systematically analyzed using various methods. The results show that the Mg-Ce composite treatment can modify irregular MgAl2O4 inclusions into spherical Mg-Ce-O composite inclusions and MgO-dominated inclusions. The density of inclusions is increased from 74.8/mm2 to 186.0/mm2, and the average size of inclusions is decreased from 2.60 μm to 1.07 μm. The Mg-Ce-O composite inclusions are effective inclusions for inducing IGF. Furthermore, the pitting potential is increased from −503 mV to −487 mV, and the corrosion rate is decreased. The order of average electronic work function is ΦMgO < ΦCe2O3 < Φα-Fe < ΦAl2O3. Ce2O3 is hard to induce pitting corrosion due to its similar electronic work function to the steel matrix. Thus, the Mg-Ce composite treatment is better than that for Mg and Ce treatment alone, and has better application prospects. [ABSTRACT FROM AUTHOR]

A DSSC's performance depends on its working electrode. Since this working electrode functions as an electron carrier, it affects how well DSSC solar cells perform. This study focused on working electrodes that use the dye DN-F05 and the Ag ions in the hybrid dye DN-F05 as a sensitizer. This research was conducted using the spin-coating method. Based on structural, optical, and electrical data, the results obtained were related to each other. It was determined that Ag has a significant influence on DSSC performance, and this discovery was also the main goal of this study. Previous studies have shown that the addition of Ag as a doping agent is an effective strategy for improving chemical and electronic properties. This can be proven through electrical measurements, which have shown an efficiency of 5.33%. However, when a significant amount of Ag is hybridized in the dye DN-F05, it will cause a decrease in DSSC performance due to the accumulation of Ag particles on the semiconductor's surface, creating a barrier to light absorption and aggregation. This is what led to the selection of a hybrid material (Ag metal), as Ag is unique and offers great potential with respect to boosting solar cells' performance. [ABSTRACT FROM AUTHOR]