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Fe1/h-BN single atom catalysts can be successfully synthesized using heat treatment of Fe phthalocyanine decorated h-BN in an oxygen atmosphere. Selectivity toward hydrocarbons can be controlled by the presence of Fe nanoparticles.

Control of a single ionic charge state by altering the number of bound electrons has been considered as an ultimate testbed for atomic charge-induced interactions and manipulations, and such subject has been studied in artificially deposited objects on thin insulating layers. We demonstrate that an entire layer of controllable atomic charges on a periodic lattice can be obtained by cleaving metallic Co

Here we propose new structures which can be represented as metallocene molecules organized into a 2D hybrid structure with two carbon layers and metal atoms sandwiched between them. We called them 2D metallocene-like structures or metal-intercalated bilayer graphene allotropes inspired by MCp2 structure. The Co and Fe metal atoms as filler between the carbon layers were considered. In addition to intriguing geometry, proposed structures show dynamical stability, which was studied by state-of-the-art computational techniques. The nature of metal-carbon bonding was determined and analyzed. Half-metallic properties were observed in the case of cobalt-containing structures. Localization of magnetic moments on individual cobalt atoms opens broad prospects for application in spintronics devices due to the shielding of a magnetic metal atom by the carbon network.

Hexagonal boron nitride (h-BN) nanosheets are a promising material for various applications including catalysis. Herein, h-BN-supported Fe-based catalysts are characterised with respect to CO2 hydrogenation reaction. Heterogeneous Fe3O4/BN, Fe3O4(Pt)/BN, and FePt/BN nanostructures are obtained via polyol synthesis in ethylene glycol. The sizes of Fe3O4 nanoparticles and their distributions over h-BN surfaces depend on the amount of H2PtCl6 added to the synthesis media. Bimetallic FePt nanoparticles are formed when Pt content is high enough. In situ TEM analysis shows the formation of core–shell h-BN@FePt nanoparticles during heating that prevents FePt NPs from further sintering during the catalytic process. The mechanism of Fe and Pt interaction is elucidated based on the molecular dynamic simulations. The FePt/BN nanomaterials show significantly higher CO2 conversion rate compared to the Fe3O4/BN and Fe3O4(Pt)/BN heterogeneous nanomaterials and exhibit almost 100% selectivity to carbon monoxide. The Fe3O4/BN and Fe3O4(Pt)/BN nanomaterials show better selectivity to hydrocarbons. The possible reaction pathways are discussed based on the calculated sorption energies of all reactants, intermediate compounds, and reaction products. The study highlights pronounced catalytic properties of the developed system and reveals a unique interaction mechanism between its components increasing their stability.

Herein we report a simple and easily scalable method for fabricating ZnO/

Funding Information: The experimental part of the research was supported by the Russian Science Foundation (No. 17-19-01787). Theoretical work was supported by the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST ‘‘MISiS’’. This work was supported by the Ministry of Science and Higher Education of the Russian Federation (project no. FZSR-2020-0007 in the frame-work of the state assignment no. 075-03-2020-097/1). A. P. T. acknowledges the EDUFI Fellowship (No. TM-19-11079) from the Finnish National Agency for Education and the Magnus Ehrnrooth Foundation (the Finnish Society of Sciences and Letters) for personal financial support. H. I., J. K., and K. M. thank the Austrian Science Fund (FWF) for funding under project no. I3181-N36. Publisher Copyright: © 2021 The Royal Society of Chemistry. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. A boost in the development of flexible and wearable electronics facilitates the design of new materials to be applied as transparent conducting films (TCFs). Although single-walled carbon nanotube (SWCNT) films are the most promising candidates for flexible TCFs, they still do not meet optoelectronic requirements demanded for their successful industrial integration. In this study, we proposed and thoroughly investigated a new approach that comprises simultaneous bilateral (outer and inner surface) SWCNT doping after their opening by thermal treatment at 400 °C under an ambient air atmosphere. Doping by a chloroauric acid (HAuCl4) ethanol solution allowed us to achieve the record value of equivalent sheet resistance of 31 ± 4 Ω sq-1 at a transmittance of 90% in the middle of the visible spectrum (550 nm). The strong p-doping was examined by open-circuit potential (OCP) measurements and confirmed by ab initio calculations demonstrating a downshift of the Fermi level of around 1 eV for the case of bilateral doping.

Using molecular dynamics simulation and evolutionary metadynamic calculations, a series of structures were revealed that possessed enthalpies and Gibbs energies lower than those of aragonite but hi...

The structural and physicochemical properties of the MoSe2/PTCDA heterostructure, which consists of two-dimensional inorganic and molecular organic semiconductors, have been studied theoretically. Features of change in the electronic properties of the PTCDA monomolecular layer on the MoSe2 surface have been described by density functional theory. The quantitative analysis of charge transfer between the heterostructure components has explained the features of coupling between the layers. The study of the optical characteristics of the heterostructure has revealed the enhancement of the absorption spectrum in the infrared range. Consequently, MoSe2/PTCDA heterostructures are promising for applications in electronics, optoelectronics, and materials for the utilization of solar energy.

Polyol method provides variety of options for microstructure control of a synthesized material. The present study aims to demonstrate that in case of Ag/h-BN nanohybrid fabrication the synthesis time requires precise tuning. Nonlinear correlation between synthesis time and Ag nanoparticles (AgNPs) formation and deposition is found and discussed. Catalytic stability of the studied system toward carbon monoxide oxidation is investigated for the first time. Two stages of catalytic activity decrease are found and associated with the sintering of AgNPs of the certain size. Correlations between Ag content, particle size distribution and temperature of complete CO conversion allow us to conclude that AgNPs, which size is below the critical value (3 nm), have a decisive role in Ag/BN nanohybrid catalytic performance. Density functional theory (DFT) calculations uncover the mechanism behind the increased catalytic activity of smaller AgNPs and highlight an importance of the Ag/BN interfacial regions.

Magnetic halogen doped MoX2 (X = S and Se) monolayers influenced the electronic structure of graphene through a proximity effect. This process was observed using state-of-the-art calculations. It was found that the substitution of a single chalcogen atom with a halogen atom (F, Cl, Br, and I) results in n-type doping of MoX2. An additional electron from the dopant is localized on binding orbitals with the nearest Mo atoms and leads to the formation of magnetism in the dichalcogenide layer. Detailed analysis of halogen doped MoX2/graphene heterostructures demonstrated the induction of spin polarization in graphene near the Fermi energy. Significant spin polarization near the Fermi energy and n-type doping were observed in the graphene layer of MoSe2/graphene heterostructures with MoSe2 doped with iodine. At the same time, fluorine-doped MoSe2 does not cause n-doping in graphene, while spin polarization still takes place. The possibility for the detection of the arrangement of the halogen impurities at the MoX2 basal plane even with the graphene layer deposited on top was demonstrated through STM measurements which will be undoubtedly useful for the fabrication of electronic schemes and elements based on the proposed heterostructures for their further application in nanoelectronics and spintronics.

One dimensional Ta2(Pd/Pt)3(S/Se)8 nanoribbons (TPS-NR) are considered as a promising material in nanoelectronics due to their intrinsic semiconducting electronic properties. In this article, we study the stability of TPS-NR by considering their oxidation process. Our calculations showed that the Ta2(Pd/Pt)3Se8 nanoribbons are more environmentally stable than Ta2(Pd/Pt)3S8-NR. We studied the thermodynamics of the formation of monovacancies and their impact on the electronic properties of TPS-NR. Additionally, the sensing properties of environmentally stable Ta2Pd3Se8 nanoribbons were investigated. The observed changes of the electronic structure and transport properties after the adsorption of CO, NH3 and NO2 molecules reveal the mechanisms of possible application of Ta2Pd3Se8 nanoribbons as a gas sensor. The electronic transport properties of the nanoribbons exhibit a notable response to the presence of gas molecules.

Oxidation is a unique process that significantly changes the structure and properties of a material. Doping of h-BN by oxygen is a hot topic in material science leading to the possibility of synthesis of novel 2D structures with customized electronic properties. It is still unclear how the atomic structure changes in the presence of external atoms during the oxidation of h-BN. We predict novel two-dimensional (2D) arrangements of boron oxynitride using the evolutionary algorithm of crystal structure prediction USPEX. All considered structures demonstrate semiconducting properties with a reduced bandgap compared with h-BN. Both molecular dynamics and phonon calculations show the dynamical stability of the new 2D B5N3O2 phase, and our calculations demonstrate that it can form a bulk layered structure with an interlayer distance larger than that of pure h-BN. The optical characterization shows a redshift of the absorption spectrum compared with pure h-BN. Incorporation of oxygen into the structure of 2D BN during synthesis or oxidation can dramatically change the covalent network of h-BN while preserving its two-dimensionality and flatness, following the presence of local dipole moments which could improve the piezoelectric properties.

Intercalation raises manifold possibilities to manipulate the properties of two-dimensional (2D) materials1, and its impact on local electronic/magnetic properties has drawn much attention with the rise of nano-structured 2D materials2,3. Typically, changing an ionic state in a solid involves a dramatic local change of energy as well as orbital/spin magnetic moment from its ground state. However, the atomic investigation of the charging process of an intercalant ion in 2D material has never been explored while such subject has been studied in artificially deposited atoms on thin insulating 2D layers using scanning probe microscopy4–7. Herein, we demonstrate an atomical manipulation of the charge and spin state of Co ions on a metallic NbS2, obtained by cleaving of Co-intercalated NbS2. Density functional theory investigation of various Co configurations reveals that the charging is possible due to a change in the crystal field at the surface and a significant coupling between NbS2 and intercalants occurs via orbitals of the a1g symmetry. The results can be generalized to numerous other combinations of intercalants and base matrixes, suggesting that intercalated transition metal dichalcogenides can be a new platform to introduce single-atom operation 2D electronics/spintronics.

The electronic structure of nickel iodide monolayer in NiI2/ScX2 (X = S, Se and Te) and NiI2/NiTe2 heterostructures was investigated by density functional theory (DFT). The spin-asymmetric semiconducting behavior of NiI2 monolayer in these interfaces was observed. The width of the band gap of the NiI2 monolayer practically does not change in heterostructures and remains at the level of 1.7 and 3.0 eV for minor and major spin channels, respectively. The NiI2 layer can be p-doped by stacking with ScX2 dichalcogenides. On the contrary, charge transfer (~0.01 |e| per f.u.) from NiTe2 leads to n-doping of NiI2. As a result, the Fermi level shifts up to the area of NiI2 conduction band with spin down carriers only, which gives prospects of using this material in spin filter applications. The electronic structure of NiI2/ScTe2 under isotropic deformation in the plane remains the same under tension and compression within 5%, except for a small change in the band gap in the composite layers of NiI2 within 25%. This allows one to conclude about the stability of the electronic properties under deformations, which gives possibility to use the heterostructures in flexible electronics devices.

Herein we analyzed the chemical reactions occurring in the process of Ag/BN hybrid fabrication in polyethylene glycol (PEG) using h-BN nano- and microparticles (BNNPs and BNMPs) during AgNO3 decomposition under UV irradiation. Decomposition of AgNO3 causes formation of Ag nanoparticles (AgNPs) and PEG oxidation reaction, the products of which interact with Ag to form Ag acetate. The polymer matrix surrounding AgNPs prevents their growth during the fabrication process. Additional low temperature annealing leads to the decomposition of the Ag acetate phase, thereby increasing the volume fraction of AgNPs. In the case of the BNNPs, the AgNP size is smaller and their distribution is more homogeneous. BNNP surface oxidation was shown to be an important factor leading to enhanced catalytic activity of Ag/BN hybrids in the CO oxidation reaction: Tinitiation = 150 °C and T100 = 200 °C. Theoretical modelling suggests that the high catalytic activity of Ag/BN nanohybrids (NHs) can be explained by the formation of thin B–O–Ag layers.

Nanohybrid materials made of h-BN nanoparticles (BNNPs) with Ag nanoparticles (AgNPs), covering their surfaces, were employed as catalysts in CO oxidation reaction. Ag/BN nanohybrids (NHs) were produced via AgNO3 decomposition under UV irradiation in polyethylene glycol (PEG) and its solutions at room temperature. Influence of the synthetic media composition on the synthesis process and resultant NHs structures were investigated. Two different structural types (Ag/BN and polymer-based structure) formed during the synthesis were studied. It was demonstrated that Ag/BN NHs synthesized in a PEG media had possessed the highest Ag concentration and uniform distribution of AgNPs. Catalytic activity tests revealed that the lowest temperature of full CO conversion (194°C) had been attained to the sample with the highest Ag content. CO oxidation mechanism on the surface of AgNPs was finally proposed based on DFT calculations.

Environmental protection requires solving the problem of utilization and reduction of CO and CO2 emissions. Herein, Au/h-BN(O) and Pt/h-BN(O) nanohybrids are thoroughly analyzed in CO oxidation and CO2 hydrogenation reactions. The nanohybrids differ in catalytic particle size and particle distribution. The particles are smaller (1–6 nm) and display a narrower size distribution in the case of Pt-based nanomaterials. The Pt/h-BN(O) nanohybrids exhibit high catalytic activity in CO conversion and carbon dioxide hydrogenation reactions. For both systems, the oxidative state of BN support affects the catalytic activity. The possible catalytic reaction mechanisms are proposed based on DFT calculations. A charge density distribution at the Pt/h-BN interface increases oxygen absorption, thereby accelerating oxygen-associated chemical reactions.

One dimensional Ta2(Pd/Pt)3(S/Se)8 nanoribbons (TPS-NR) are considered as a promising material in nanoelectronics due to their intrinsic semiconducting electronic properties. In this article, we study the stability of TPS-NR by considering their oxidation process. Our calculations showed that the Ta2(Pd/Pt)3Se8 nanoribbons are more environmentally stable than Ta2(Pd/Pt)3S8-NR. We studied the thermodynamics of the formation of monovacancies and their impact on the electronic properties of TPS-NR. Additionally, the sensing properties of environmentally stable Ta2Pd3Se8 nanoribbons were investigated. The observed changes of the electronic structure and transport properties after the adsorption of CO, NH3 and NO2 molecules reveal the mechanisms of possible application of Ta2Pd3Se8 nanoribbons as a gas sensor. The electronic transport properties of the nanoribbons exhibit a notable response to the presence of gas molecules.

NaCl is one of the simplest compounds and was thought to be well-understood, and yet, unexpected complexities related to it were uncovered at high pressure and in low-dimensional states. Here, exotic hexagonal NaCl thin films on the (110) diamond surface were crystallized in the experiment following a theoretical prediction based on

Single-walled carbon nanotubes (SWCNTs) possess extraordinary physical and chemical properties. Thin films of randomly oriented SWCNTs have great potential in many opto-electro-mechanical applications. However, good adhesion of SWCNT films with a substrate material is pivotal for their practical use. Here, for the first time, we systematically investigate the adhesion properties of SWCNT thin films with commonly used substrates such as glass (SiO2), indium tin oxide (ITO), crystalline silicon (C-Si), amorphous silicon (a-Si:H), zirconium oxide (ZrO2), platinum (Pt), polydimethylsiloxane (PDMS), and SWCNTs for self-adhesion using atomic force microscopy. By comparing the results obtained in air and inert Ar atmospheres, we observed that the surface state of the materials greatly contributes to their adhesion properties. We found that the SWCNT thin films have stronger adhesion in an inert atmosphere. The adhesion in the air can be greatly improved by a fluorination process. Experimental and theoretical analyses suggest that adhesion depends on the atmospheric conditions and surface functionalization.

The microstructure of aragonite, one of the main bio-mineral and component of bio-inspired materials, was described in numerous investigations. Using transmission electron microscopy (TEM), for the first time we show the effect of temperature on aragonite microstructure. The local increase of (0.5 0.5 0) reflections intensities and appearance of satellite reflections in [11̅0] zone axis were observed above 350°C. We explain the appearance of satellite reflections by the generation and ordering of {110} twin boundaries and suggest new thermal mechanism of the twin boundaries generation. We check the viability of this mechanism by ab initio molecular dynamics (AIMD) simulations and generalized solid state nudge elastic band (g-SSNEB) calculations.

The structural as well as electronic properties of PtPd nanoparticles (NPs) were investigated by using molecular dynamics simulations and density functional theory calculations. A wide range of NPs...

A novel quasi-two-dimensional monolayer structure with orthorhombic symmetry based on cobalt carbide, o-CoC, has been considered. This structure supplements a recently discovered family of quasi-two-dimensional compounds based on transition metals. The dynamic stability of a monolayer has been demonstrated. Its mechanical and electronic characteristics have been studied.

Electrocatalytic hydrogen evolution reaction (HER) in alkaline solution is hindered by its sluggish kinetics toward water dissociation. Nickel-based catalysts, as low-cost and effective candidates, show great potentials to replace platinum (Pt)-based materials in the alkaline media. The main challenge regarding this type of catalysts is their relatively poor durability. In this work, we conceive and construct a charge-polarized carbon layer derived from carbon quantum dots (CQDs) on Ni3N nanostructure (Ni3N@CQDs) surfaces, which simultaneously exhibit durable and enhanced catalytic activity. The Ni3N@CQDs shows an overpotential of 69 mV at a current density of 10 mA cm–2 in a 1 M KOH aqueous solution, lower than that of Pt electrode (116 mV) at the same conditions. Density functional theory (DFT) simulations reveal that Ni3N and interfacial oxygen polarize charge distributions between originally equal C–C bonds in CQDs. The partially negatively charged C sites become effective catalytic centers for the ke...

The structure and properties of high-pressure phases of iron nitrides Fe7N3 in the pressure range of 50–150 GPa have been studied with ab initio calculations within the electron density functional theory. A new phase Amm2-Fe7N3, which is the most energetically favorable in the pressure range of 43–128 GPa, has been found using the USPEX (Universal Structure Predictor: Evolutionary Xtallography) algorithms. It has been thermodynamically shown that another high-pressure phase β-Fe7N3 is isostructural to a similar phase of iron carbide. The elastic properties have been calculated for all modifications e-, β-, and Amm2-Fe7N3 stable at high pressures.

The grafting of carboxyl groups enhances cell adhesion and can be used for immobilization of different biomolecules onto plasma-treated materials. The process, however, was not well optimized due to lack of clear understanding of the mechanisms of carboxylic group incorporation into plasma and their grafting to polymer surface. In this work the deposition of COOH plasma polymers from CO2/C2H4/Ar pulsed discharge has been studied depending on the gas mixture and duty cycle. We have demonstrated that the CO2/C2H4/Ar plasma with adjustable thickness of COOH functionalized layer and high stability of the grafted functions in water is a better solution for the COOH surface functionalization compared to the thoroughly analyzed CO2 plasma. The concentration of different carbon environments and the density of COOH groups have been measured by using chemical derivatization combined with X-ray photoelectron spectroscopy. It has been found that the CO2/C2H4/Ar plasma mainly contains ester groups (COOC), the COOH/COOC ratio being between 0.03 and 0.08. The water stability of the COOH groups was significantly higher compared to ester environment, so immersing in water for 24 h allowed to increase the COOH/COOC ratio by a factor of 3. The mechanisms of the CO2 molecule attachment to hydrocarbon chains on the polymer surface and those located inside the plasma were modeled using ab initio calculations.

The rapid development of flexible and transparent electronics imposes growing demands on new highly conductive, optically transparent and mechanically robust materials. Single-walled carbon nanotubes (SWCNTs) are a unique material with diverse exceptional properties, which could be utilized in many fields of science and technology. We have synthesized high quality SWCNTs using an aerosol CVD method and examined doping technique to enhance their optoelectronic performance for transparent and conducting applications. We empirically selected the most effective dopant, HAuCl4, dissolved in various solvents (ethanol, acetonitrile, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, and n-methyl-2-pyrrolidone). We optimized the doping conditions and obtained the state-of-the-art sheet resistance value of as low as 40 Ω/□ at the transmittance of 90% at the wavelength of 550 nm.

Hexagonal boron nitride nanoparticles (BNNPs) with different amounts of boron oxide on their surfaces were used as catalyst carriers. BNNPs/Ag nanohybrids were produced via ultraviolet (UV) decomposition of AgNO3 in a mixture of polyethylene glycol and BNNPs. High temperature (1600 °C, 1.5 h) vacuum annealing of BNNPs promoted small size (5–10 nm) Ag nanoparticle (AgNPs) formation on BN surfaces with narrow size distribution, whereas using BNNPs in their as-produced state resulted in large AgNPs with various sizes. An increase in the B2O3 content on the BNNPs surfaces (up to a certain point) during BNNP pre-annealing in air led to larger amounts of AgNPs on their surfaces. Experimental results were confirmed by theoretical calculations of the adhesion energy of the (111)Ag with (0001)h-BN and (100)B2O3 surfaces. In contrast to the nonwettability of the h-BN surface by AgNPs, silver bound well to B2O3 with the formation of a covalent bond at the interface. Excessive fraction of B2O3, however, was not beneficial in terms of obtaining the optimal contents of AgNPs. Results of catalytic activity tests demonstrated that BNNPs/Ag nanohybrids synthesized using BNNPs with an optimized amount of B2O3 possess significantly enhanced catalytic activity compared to BNNPs without or with excess amounts of oxide. Finally, the catalytic activity of nanohybrids was theoretically analyzed using density functional theory (DFT) calculations.

Two-layer freestanding heterostructure consisting of VS2 monolayer and graphene was investigated by means of density functional theory computations as a promising anode material for lithium-ion batteries (LIB). We have investigated lithium atoms’ sorption and diffusion on the surface and in the interface layer of VS2/graphene heterostructure with both H and T configurations of VS2 monolayer. The theoretically predicted capacity of VS2/graphene heterostructures is high (569 mAh/g), and the diffusion barriers are considerably lower for the heterostructures than for bulk VS2, so that they are comparable to barriers in graphitic LIB anodes (∼0.2 eV). Our results suggest that VS2/graphene heterostructures can be used as a promising anode material for lithium-ion batteries with high power density and fast charge/discharge rates.

Two-dimensional materials such as hexagonal boron nitride (h-BN) and graphene have attracted wide attention in nanoelectronics and spintronics. Since their electronic characteristics are strongly affected by the local atomic structure, the heteroatom doping could allow us to tailor the electronic and physical properties of two-dimensional materials. In this study, a non-chemical method of heteroatom doping into h-BN under high-energy ion irradiation was demonstrated for the LiF/h-BN/Cu heterostructure. Spectroscopic analysis of chemical states on the relevant atoms revealed that 6% ± 2% fluorinated h-BN is obtained by the irradiation of 2.4 MeV Cu2+ ions with the fluence up to 1014 ions cm-2. It was shown that the high-energy ion irradiation leads to a single-sided fluorination of h-BN by the formation of the fluorinated sp 3-hybridized BN.

Two-dimensional (2D) membranes consisting of a single layer of Mo atoms were recently manufactured [ Adv. Mater. 2018 , 30 , 1707281 ] from MoSe2 sheets by sputtering Se atoms using an electron beam in a transmission electron microscope. This is an unexpected result as formation of Mo clusters should energetically be more favorable. To get microscopic insights into the energetics of realistic Mo membranes and nonstoichiometric phases of transition-metal dichalcogenides (TMDs) MaXb, where M = Mo and W and X = S, Se, and Te, we carry out first-principles calculations and demonstrate that the membranes, which can be referred to as metallic quantum dots embedded into a semiconducting matrix, can be stabilized by charge transfer. We also show that an ideal neutral 2D Mo or W sheet is not flat but a corrugated structure, with a square lattice being the lowest-energy configuration. We further demonstrate that several intermediate nonstoichiometric phases of TMDs are possible as they have lower formation energies than pure metal membranes. Among them, the orthorhombic metallic 2D M4X4 phase is particularly stable. Finally, we study the properties of this phase in detail and discuss how it can be manufactured by the top-down approaches.

A rapid increase in the number of antibiotic-resistant bacteria urgently requires the development of new more effective yet safe materials to fight infection. Herein, we uncovered the contribution of different metal nanoparticles (NPs) (Pt, Fe, and their combination) homogeneously distributed over the surface of nanostructured TiCaPCON films in the total antibacterial activity toward eight types of clinically isolated bacterial strains (Escherichia coli K261, Klebsiella pneumoniae B1079k/17-3, Acinetobacter baumannii B1280A/17, Staphylococcus aureus no. 839, Staphylococcus epidermidis i5189-1, Enterococcus faecium Ya-235: VanA, E. faecium I-237: VanA, and E. coli U20) taking into account various factors that can affect bacterial mechanisms: surface chemistry and phase composition, wettability, ion release, generation of reactive oxygen species (ROS), potential difference and polarity change between NPs and the surrounding matrix, formation of microgalvanic couples on the sample surfaces, and contribution of a passive oxide layer, formed on the surface of films, to general kinetics of the NP dissolution. The results indicated that metal ion implantation and subsequent annealing significantly changed the chemistry of the TiCaPCON film surface. This, in turn, greatly affected the shedding of ions, ROS formation, potential difference between film components, and antibacterial activity. The presence of NPs was critical for ROS generation under UV or daylight irradiation. By eliminating the potential contribution of ions and ROS, we have shown that bacteria can be killed using direct microgalvanic interactions. The possibility of charge redistribution at the interfaces between Pt NPs and TiO2 (anatase and rutile), TiC, TiN, and TiCN components was demonstrated using density functional theory calculations. The TiCaPCON-supported Pt and Fe NPs were not toxic for lymphocytes and had no effect on the ability of lymphocytes to activate in response to a mitogen. This study provides new insights into understanding and designing of antibacterial yet biologically safe surfaces.

The chemical inertness of the defect-free basal plane confers environmental stability to MoS2 single-layers, but it also limits their chemical versatility and catalytic activity. The stability of the pristine MoS2 basal plane against oxidation under ambient conditions is a widely accepted assumption in the interpretation of various studies and applications. However, single-atom level structural investigations reported here reveal that oxygen atoms spontaneously incorporate into the basal plane of MoS2 single layers during ambient exposure. Our scanning tunneling microscopy investigations reveal a slow oxygen substitution reaction, upon which individual sulfur atoms are one by one replaced by oxygen, giving rise to solid solution type 2D MoS2-xOx crystals. O substitution sites present all over the basal plane act as single-atomic active reaction centers, substantially increasing the catalytic activity of the entire MoS2 basal plane for the electrochemical H2 evolution reaction., 6 pages, 5 figures

Among the main appeals of single-atom catalysts are the ultimate efficiency of material utilization and the well-defined nature of the active sites, holding the promise of rational catalyst design. A major challenge is the stable decoration of various substrates with a high density of individually dispersed and uniformly active monatomic sites. Transition metal chalcogenides (TMCs) are broadly investigated catalysts, limited by the relative inertness of their pristine basal plane. We propose that TMC single layers modified by substitutional heteroatoms can harvest the synergistic benefits of stably anchored single-atom catalysts and activated TMC basal planes. These solid-solution TMC catalysts offer advantages such as simple and versatile synthesis, unmatched active site density, and a stable and well-defined single-atom active site chemical environment. The unique features of heteroatom-doped two-dimensional TMC crystals at the origin of their catalytic activity are discussed through the examples of various TMC single layers doped with individual oxygen heteroatoms.

Correction for ‘Highly efficient bilateral doping of single-walled carbon nanotubes’ by Anastasia E. Goldt et al., J. Mater. Chem. C, 2021, 9, 4514–4521, DOI: 10.1039/D0TC05996J.

The behavior of alkaline carbonates at high pressure is poorly understood. Indeed, theoretical and experimental investigations of the pressure induced structural changes have appeared in the literature only sporadically. In this article we use evolutionary crystal structure prediction algorithms based on density functional theory to determine crystal structures of high-pressure phases of Li2CO3, Na2CO3, and K2CO3. Our calculations reveal several new structures for each compound in the pressure range of 0–100 GPa. Cation arrays of all high-pressure structures are of the AlB2 topological type. The comparison of cation arrays of ambient and high-pressure structures with that of binary A2B compounds indicates an analogy between high-pressure behavior of alkaline carbonates and alkaline sulfides (oxides, selenides, tellurides), which under compression go through the following series of phase transitions: anti-CaF2 → anti-PbCl2 → Ni2In → AlB2. All structures presented in this trend are realized in the high-pres...