Lying or Standing of Thiophene on a Surface Determines the Reaction Difference.

Adsorption configurations of molecules on a surface play an important role in the on-surface reaction. In the on-surface synthesis reaction, most of the molecules prefer the lying adsorption configuration to maximize the interaction between the molecule and substrate. In this work, we report an on-surface study of 2,3,4,5-tetrabromothiophene by scanning tunneling microscopy, density functional theory, and X-ray photoelectron spectroscopy.

Pore Size Distribution and Fractal Characteristics of Deep Coal in the Daning-Jixian Block on the Eastern Margin of the Ordos Basin.

Important breakthroughs have recently been achieved in deep coalbed methane (CBM) exploration and development in regions such as the eastern margin of the Ordos Basin, China. Investigating the development characteristics of various-scale pores in deep coalbeds is of great significance for resource assessment and selection of favorable zones for CBM exploration. Herein, six deep coal samples were selected from the Shanxi and Taiyuan Formations in the Daning-Jixian block on the eastern margin of the Ordos Basin.

Epitaxial Growth of Monolayer SnP with High Mobility and Chiral Boundary Junctions.

Two-dimensional materials with layered structures, appropriate band gaps, and high carrier mobility have attracted tremendous interest for their potential applications. Here we report the growth of monolayer SnP on Au(111) surfaces by molecular beam epitaxy. The kinetic processes for the growth and the crystalline properties are studied by scanning tunneling microscopy.

A fingerprint-like supramolecular-assembled AgPO/polydopamine/g-CN heterojunction nanocomposite for enhanced solar-driven oxygen evolution in vivo.

Biocompatible photocatalytic water-splitting systems are promising for tissue self-oxygenation. Herein, a structure-function dual biomimetic fingerprint-like silver phosphate/polydopamine/graphitic carbon nitride (AgPO/PDA/g-CN) heterojunction nanocomposite is proposed for enhanced solar-driven oxygen (O) evolution in vivo in situ. Briefly, a porous nitrogen-defected g-CN nanovoile (CN) is synthesized as the base.

Conductive catalysis by subsurface transition metals.

The nature of catalysis has been hotly pursued for over a century, and current research is focused on understanding active centers and their electronic structures. Herein, the concept of conductive catalysis is proposed and verified by theoretical simulations and experimental observations. Metallic systems containing buried catalytically active transitional metals and exposed catalytically inert main group metals are constructed, and the electronic interaction between them metallic bonding is disclosed.

Highly Efficient and Stable Methane Dry Reforming Enabled by a Single-Site Cationic Ni Catalyst.

Zeolite-supported nickel (Ni) catalysts have been extensively studied for the dry reforming of methane (DRM). It is generally believed that prior to or during the reaction, Ni is reduced to a metallic state to act as the catalytic site. Here, we employed a ligand-protected synthesis method to achieve a high degree of Ni incorporation into the framework of the MFI zeolite.

Ferromagnetic ordering correlated strong metal-oxygen hybridization for superior oxygen reduction reaction activity.

The efficiency of transition-metal oxide materials toward oxygen-related electrochemical reactions is classically controlled by metal-oxygen hybridization. Recently, the unique magnetic exchange interactions in transition-metal oxides are proposed to facilitate charge transfer and reduce activation barrier in electrochemical reactions. Such spin/magnetism-related effects offer a new and rich playground to engineer oxide electrocatalysts, but their connection with the classical metal-oxygen hybridization theory remains an open question.

Bilayer Kagome Borophene with Multiple van Hove Singularities.

The appearance of van Hove singularities near the Fermi level leads to prominent phenomena, including superconductivity, charge density wave, and ferromagnetism. Here a bilayer Kagome lattice with multiple van Hove singularities is designed and a novel borophene with such lattice (BK-borophene) is proposed by the first-principles calculations. BK-borophene, which is formed via three-center two-electron (3c-2e) σ-type bonds, is predicted to be energetically, dynamically, thermodynamically, and mechanically stable.

Quinoxalineimide-Based Semiconducting Polymer Nanoparticles as an Effective Phototheranostic for the Second Near-Infrared Fluorescence Imaging and Photothermal Therapy.

Multifunctional theranostics play a critical role in improving the efficacy of photothermal therapy and tumor fluorescence imaging; however, they require the integration of complex components into a single theranostic system, and their response in the second near-infrared (NIR-II) region is constrained by wavelengths of a photosensitizer. To address this issue, we herein developed a novel multifunctional thiazole-fused quinoxalineimide semiconducting polymer (named PQIA-BDTT), which exhibits NIR-II fluorescence and photothermal properties. PQIA-BDTT nanoparticles achieved an impressively high photothermal conversion efficiency (72.

Moiré-Pattern Modulated Electronic Structures of GaSe/HOPG Heterostructure.

Conventional two-dimensional electron gas (2DEG) typically occurs at the interface of semiconductor heterostructures and noble metal surfaces, but it is scarcely observed in individual 2D semiconductors. In this study, few-layer gallium selenide (GaSe) grown on highly ordered pyrolytic graphite (HOPG) is demonstrated using scanning tunneling microscopy and spectroscopy (STM/STS), revealing that the coexistence of quantum well states (QWS) and 2DEG. The QWS are located in the valence bands and exhibit a peak feature, with the number of quantum wells being equal to the number of atomic layers.

Enhanced Electron-Hole Separation in Phosphorus-Coordinated Co Atom on g-CN toward Photocatalytic Overall Water Splitting.

Revealing the decoration mode of g-CN and understanding the physical mechanism of overall water splitting is important for the further improvement of the photocatalytic activity of g-CN-based materials. With core level shift and molecular dynamics simulations based on first-principles calculations, Co(PH) anchored on the triazine of g-CN is determined as a stable single-atom catalyst with high efficiency for photocatalytic overall water splitting. The separated spin-polarized charge density distribution of valence-band maximum and conduction-band minimum states is beneficial for the long lifetime of photoexcited electrons and holes.

Interface engineering breaks both stability and activity limits of RuO for sustainable water oxidation.

Designing catalytic materials with enhanced stability and activity is crucial for sustainable electrochemical energy technologies. RuO is the most active material for oxygen evolution reaction (OER) in electrolysers aiming at producing 'green' hydrogen, however it encounters critical electrochemical oxidation and dissolution issues during reaction. It remains a grand challenge to achieve stable and active RuO electrocatalyst as the current strategies usually enhance one of the two properties at the expense of the other.

Tuning Fe Spin Moment in Fe-N-C Catalysts to Climb the Activity Volcano via a Local Geometric Distortion Strategy.

As the most promising alternative to platinum-based catalysts for cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells, further performance enhancement of Fe-N-C catalysts is highly expected to promote their wide application. In Fe-N-C catalysts, the single Fe atom forms a square-planar configuration with four adjacent N atoms (D symmetry). Breaking the D symmetry of the FeN active center provides a new route to boost the activity of Fe-N-C catalysts.

Nearly Ideal Two-Dimensional Electron Gas Hosted by Multiple Quantized Kronig-Penney States Observed in Few-Layer InSe.

A theoretical ideal two-dimensional electron gas (2DEG) was characterized by a flat density of states independent of energy. Compared with conventional two-dimensional free-electron systems in semiconductor heterojunctions and noble metal surfaces, we report here the achievement of ideal 2DEG with multiple quantized states in few-layer InSe films. The multiple quantum well states (QWSs) in few-layer InSe films are found, and the number of QWSs is strictly equal to the number of atomic layers.

Ultrathin Van der Waals Antiferromagnet CrTe for Fabrication of In-Plane CrTe /CrTe Monolayer Magnetic Heterostructures.

Ultrathin van der Waals (vdW) magnets are heavily pursued for potential applications in developing high-density miniaturized electronic/spintronic devices as well as for topological physics in low-dimensional structures. Despite the rapid advances in ultrathin ferromagnetic vdW magnets, the antiferromagnetic counterparts, as well as the antiferromagnetic junctions, are much less studied owing to the difficulties in both material fabrication and magnetism characterization. Ultrathin CrTe layers have been theoretically proposed to be a vdW antiferromagnetic semiconductor with intrinsic intralayer antiferromagnetism.

Pt Atom on the Wall of Atomic Layer Deposition (ALD)-Made MoS Nanotubes for Efficient Hydrogen Evolution.

Single-atom catalysts (SACs) can achieve excellent catalytic efficiency at ultralow catalyst consumptions. Herein, platinum (Pt) atoms are fixed on the wall of atomic layer deposition (ALD)-made molybdenum disulfide nanotube arrays (MoS -NTA) for efficient hydrogen evolution reaction (HER). More concretely, MoS -NTA with different nanotube diameters and wall thicknesses are fabricated by a sacrificial strategy of anodic aluminum oxide (AAO) template via ALD; then Pt atoms are fixed on the wall of Ti C -supported MoS -NTA as a catalytic system.

Activating Inert Surface Pt Single Atoms via Subsurface Doping for Oxygen Reduction Reaction.

The performance of single-atom catalysts strongly depends on their particular coordination environments in the near-surface region. Herein, we discover that engineering extra Pt single atoms in the subsurface (Pt) can significantly enhance the catalytic efficiency of surface Pt single atoms toward the oxygen reduction reaction (ORR). We experimentally and theoretically investigated the effects of the Pt single atoms implanted in different positions of the subsurface of Co particles.

Concomitant Photoresponsive Chiroptics and Magnetism in Metal-Organic Frameworks at Room Temperature.

Stimulus-responsive metal-organic frameworks (MOFs) can be used for designing smart materials. Herein, we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at room temperature. In this design, two specific nonphotochromic ligands are selected to construct enantiomeric MOFs, {Cu(L-mal)(bpy)(HO)·3HO} (1) and {Cu(D-mal)(bpy)(HO)·3HO} (2) (mal = malate, bpy = 4, 4' - bipyridine), which can alter their color, magnetism, and chiroptics concurrently in response to light.

Pd-Pt Tesseracts for the Oxygen Reduction Reaction.

Hollow frame structures are of special interest in the realm of catalysis since they hold only ridges and hollow interiors, enabling the accessibility of active sites to the most extent. Herein, we prepared Pd-Pt hollow frame structures composed of double-shell cubes linked by body diagonals as an efficient catalyst toward the oxygen reduction reaction (ORR), inspired by the 4D analogue of a cube, denoted as a tesseract. The etching process involves the selective removal of Pd atoms and the subsequent rearrangement of the remaining Pd and Pt atoms.

Surface Nitrogen-Injection Engineering for High Formation Rate of CO Reduction to Formate.

In this study, we highlight that surface nitrogen-injection engineering brings a high formation rate for CO reduction to formate, which is high level among the reported electrocatalysts. Surface nitrogen-injection engineering can increase the amounts of active sites and optimize the electronic structure simultaneously. Taking an example of SnS precursors, the final-obtained surface N-enriched Sn(S) nanosheets (denoted as N-Sn(S) nanosheets) exhibit a 5-fold of current density and 2.

Reversible Potassium Intercalation in Blue Phosphorene-Au Network Driven by an Electric Field.

Foreign atom intercalation into an interface alters the strength of interlayer interaction and leads to the novel types of desirable properties. Here, we report an investigation via scanning tunnelling microscopy (STM) and scanning tunnelling spectroscopy (STS) of reversible potassium (K) intercalation in the blue phosphorene (blueP)-Au network that can be locally induced by an external electric field. The unique structure of the blueP-Au network provides large space in its pores for the intercalation and deintercalation process.

Well-Defined Single-Atom Cobalt Catalyst for Electrocatalytic Flue Gas CO Reduction.

Single-atom Co catalyst Co-Tpy-C with well-defined sites is synthesized by pyrolysis of a Co terpyridine (Tpy) organometallic complex. The Co-Tpy-C catalyst exhibits excellent activity for the electrochemical CO reduction reaction in aqueous electrolyte, with CO faradaic efficiency (FE) of over 95% from -0.7 to -1.

Correlation-driven eightfold magnetic anisotropy in a two-dimensional oxide monolayer.

Engineering magnetic anisotropy in two-dimensional systems has enormous scientific and technological implications. The uniaxial anisotropy universally exhibited by two-dimensional magnets has only two stable spin directions, demanding 180° spin switching between states. We demonstrate a previously unobserved eightfold anisotropy in magnetic SrRuO monolayers by inducing a spin reorientation in (SrRuO)/(SrTiO) superlattices, in which the magnetic easy axis of Ru spins is transformed from uniaxial 〈001〉 direction ( < 3) to eightfold 〈111〉 directions ( ≥ 3).