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Abstract: The metal oxides/graphene composites are one of the most promising supercapacitors (SCs) electrode materials. However, rational synthesis of such electrode materials with controllable conductivity and electrochemical activity is the topical challenge for high‐performance SCs. Here, the Co3O4/graphene composite is taken as a typical example and develops a novel/universal one‐step laser irradiation method that overcomes all these challenges and obtains the oxygen‐vacancy abundant ultrafine Co3O4 nanoparticles/graphene (UCNG) composites with high SCs performance. First‐principles calculations show that the surface oxygen vacancies can facilitate the electrochemical charge transfer by creating midgap electronic states. The specific capacitance of the UCNG electrode reaches 978.1 F g−1 (135.8 mA h g−1) at the current densities of 1 A g−1 and retains a high capacitance retention of 916.5 F g−1 (127.3 mA h g−1) even at current density up to 10 A g−1, showing remarkable rate capability (more than 93.7% capacitance retention). Additionally, 99.3% of the initial capacitance is maintained after consecutive 20 000 cycles, demonstrating enhanced cycling stability. Moreover, this proposed laser‐assisted growth strategy is demonstrated to be universal for other metal oxide/graphene composites with tuned electrical conductivity and electrochemical activity. [ABSTRACT FROM AUTHOR]

In anisotropic materials, the electrical and atomic transport along the weak interaction direction is usually much slower than that along the chemical bond direction. However, Te, an important semiconductor composed of helical atomic chains, exhibits nearly isotropic electrical transport between intrachain and interchain directions. Using first-principles calculations to study bulk and few-layer Te, we show that this isotropy is related to similar effective masses and potentials for charge carriers along different transport directions, benefiting from the delocalization of the lone-pair electrons. This delocalization also enhances the interchain binding, and thus facilitates diffusion of vacancies and interstitial atoms across the chains, which together with the fast intrachain diffusion enable rapid self-healing of these defects at low temperature. Interestingly, the interstitial atoms diffuse along the chain via a concerted rotation mechanism. Our work reveals the unconventional properties underlying the superior performance of Te while providing insight into the transport in anisotropic materials. [ABSTRACT FROM AUTHOR]

A unique strategy is reported to constrain the nucleation centers for multilayer graphene (MLG) and, later, single-crystal graphene domains by gettering carbon source on backside of the flat Cu foil, during chemical vapor deposition. Hitherto, for a flat Cu foil, the top-surface-based growth mechanism is emphasized, while overlooking the graphene on the backside. However, the systematic experimental findings indicate a strong correlation between the backside graphene and the nucleation centers on the top-surface, governed by the carbon diffusion through the bulk Cu. This understanding steers to devise a strategy to mitigate the carbon diffusion to the top-surface by using a carbon 'getter' substrate, such as nickel, on the backside of the Cu foil. Depth profiling of the nickel substrate, along with the density functional theory calculations, verifies the gettering role of the nickel support. The implementation of the backside carbon gettering approach on single-crystal graphene growth results in lowering the nucleation density by two orders of magnitude. This enables the single-crystal domains to grow by 6 mm laterally on the untreated Cu foil. Finally, the growth of large-area polycrystalline single layer graphene, free of unwanted MLG domains, with significantly improved field-effect mobility of ≈6800 cm2 V−1 s−1 is demonstrated. [ABSTRACT FROM AUTHOR]

Post-stroke depression (PSD) is one of the most common neuropsychiatric consequence of stroke, affecting cognitive function, recovery of somatic function, and patient survival. The aim of this study was to evaluate whether Chaihu-Shugan-San, a traditional Chinese medicine formula used clinically to treat depression, could improve symptoms in a rat model for PSD, to investigate the potential mechanisms, and to validate the findings in an in vitro oxygen and glucose deprivation (OGD) model. Male rats were subjected to middle cerebral artery occlusion (MCAO) and to chronic unpredictable mild stress (CUMS). The rats were then allocated to experimental groups (n = 15) that were treated with Chaihu-Shugan-San, a JAK-STAT3 inhibitor, a GSK3β overexpressing virus, or an empty virus (control). The subjects allocated to each group, as well as those that received no treatment and rats that did not undergo MCAO/CUMS, were then subjected to forced swimming, tail suspension, and sugar water preference tests, and their neurological deficit score was determined. Inflammatory factor levels and the expression of proteins related to the JAK/STAT3-GSK3β/PTEN/Akt pathway were measured, and the synaptic ultrastructure was observed using transmission electron microscopy. Flow cytometry showed microglia polarization towards the M1 phenotype in an in vitro PSD model, which was reversed after treatment with a GSK3β overexpression virus, Chaihu-Shugan-San, or a JAK-STAT3 inhibitor. The results showed that Chaihu-Shugan-San has a therapeutic effect on an in vivo model for PSD and can regulate microglia polarization through the activation of the JAK/STAT3-GSK3β/PTEN/Akt pathway, suggesting that it exerts its effect via the inhibition of neuroinflammation. [Display omitted] • Post-stroke depression (PSD) is a common neuropsychiatric consequence of stroke. • We used both an in vivo and an in vitro model to evaluate potential therapies for PSD. • Chaihu-Shugan-San, a traditional Chinese medicine formula, improved PSD symptoms. • This effect involved the activation of the JAK/STAT3-GSK3β/PTEN/Akt pathway. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) metal carbides and nitrides, called MXenes, have attracted great interest for applications such as energy storage. We demonstrate their potential as Schottky-barrier-free metal contacts to 2D semiconductors, providing a solution to the contact-resistance problem in 2D electronics. On the basis of first-principles calculations, we find that the surface chemistry strongly affects Fermi level of MXenes: O termination always increases the work function with respect to that of bare surface, OH always decreases it, whereas F exhibits either trend depending on the specific material. This phenomenon originates from the effect of surface dipoles, which together with the weak Fermi level pinning, enable Schottky-barrier-free hole (or electron) injection into 2D semiconductors through van der Waals junctions with some of the O-terminated (or all the OH-terminated) MXenes. Furthermore, we suggest synthetic routes to control surface terminations based on calculated formation energies. This study enhances understanding of the correlation between surface chemistry and electronic/transport properties of 2D materials, and also gives predictions for improving 2D electronics. [ABSTRACT FROM AUTHOR]

Defects play important roles in semiconductors (SCs). Unlike those in bulk SCs, defects in two-dimensional (2D) SCs are exposed to the surrounding environment, which can potentially modify their properties/functions. Air is a common environment, yet its impact on the defects in 2D SCs still remains elusive. Here we study the interaction between air and chalcogen vacancies (VX), the most typical defects in 2D SCs. Although the interaction is weak for most molecules in air, O2 can be chemisorbed at VX with a barrier that correlates with the SC cohesive energy and can be overcome even at room temperature for certain SCs. Importantly, the chemisorbed O2 changes the VX from commonly believed harmful carrier-traps to electronically benign sites. This unusual behavior originates from the isovalence between O2 and X when bonded with metal. Based on these findings, af acile approach is proposed to improve the performance of 2D SCs by using air/O2 to passivate the defects. [ABSTRACT FROM AUTHOR]

Defects play important roles in semiconductors (SCs). Unlike those in bulk SCs, defects in two-dimensional (2D) SCs are exposed to the surrounding environment, which can potentially modify their properties/functions. Air is a common environment, yet its impact on the defects in 2D SCs still remains elusive. Here we study the interaction between air and chalcogen vacancies (VX), the most typical defects in 2D SCs. Although the interaction is weak for most molecules in air, O2 can be chemisorbed at VX with a barrier that correlates with the SC cohesive energy and can be overcome even at room temperature for certain SCs. Importantly, the chemisorbed O2 changes the VX from commonly believed harmful carrier-traps to electronically benign sites. This unusual behavior originates from the isovalence between O2 and X when bonded with metal. Based on these findings, a facile approach is proposed to improve the performance of 2D SCs by using air/O2 to passivate the defects. [ABSTRACT FROM AUTHOR]

Thedeep gap states created by defects in semiconductors typicallydeteriorate the performance of (opto)electronic devices. This haslimited the applications of two-dimensional (2D) metal dichalcogenides(MX2) and underscored the need for a new 2D semiconductorwithout defect-induced deep gap states. In this work, we demonstratethat a 2D mono-elemental semiconductor is a promising candidate. Thisis exemplified by first-principles study of 2D phosphorus (P), a recentlyfabricated high-mobility semiconductor. Most of the defects, includingintrinsic point defects and grain boundaries, are electronically inactive,thanks to the homoelemental bonding, which is not preferred in heteroelementalsystem such as MX2. Unlike MX2, the edges ofwhich create deep gap states and cannot be eliminated by passivation,the edge states of 2D P can be removed from the band gap by hydrogentermination. We further find that both the type and the concentrationof charge carriers in 2D P can be tuned by doping with foreign atoms.Our work sheds light on the role of defects in the electronic structureof materials. [ABSTRACT FROM AUTHOR]

Bi- and trilayer graphene have attracted intensive interest due to their rich electronic and optical properties, which are dependent on interlayer rotations. However, the synthesis of high-quality large-size bi- and trilayer graphene single crystals still remains a challenge. Here, the synthesis of 100 μm pyramid-like hexagonal bi- and trilayer graphene single-crystal domains on Cu foils using chemical vapor deposition is reported. The as-produced graphene domains show almost exclusively either 0° or 30° interlayer rotations. Raman spectroscopy, transmission electron microscopy, and Fourier-transformed infrared spectroscopy were used to demonstrate that bilayer graphene domains with 0° interlayer stacking angles were Bernal stacked. Based on first-principle calculations, it is proposed that rotations originate from the graphene nucleation at the Cu step, which explains the origin of the interlayer rotations and agrees well with the experimental observations. [ABSTRACT FROM AUTHOR]

Bi- and trilayer graphene have attracted intensive interest due to their rich electronic and optical properties, which are dependent on interlayer rotations. However, the synthesis of high-quality large-size bi- and trilayer graphene single crystals still remains a challenge. Here, the synthesis of 100 μm pyramid-like hexagonal bi- and trilayer graphene single-crystal domains on Cu foils using chemical vapor deposition is reported. The as-produced graphene domains show almost exclusively either 0° or 30° interlayer rotations. Raman spectroscopy, transmission electron microscopy, and Fourier-transformed infrared spectroscopy were used to demonstrate that bilayer graphene domains with 0° interlayer stacking angles were Bernal stacked. Based on first-principle calculations, it is proposed that rotations originate from the graphene nucleation at the Cu step, which explains the origin of the interlayer rotations and agrees well with the experimental observations. [ABSTRACT FROM AUTHOR]

Was wäre, wenn …︁? Zweidimensionalen Borschichten (rot skizziert) wurden auf theoretischem Weg wünschenswerte Eigenschaften für Anwendungen in der Nanoelektronik vorhergesagt, ihre Synthese ist aber eine Herausforderung. Die Tauglichkeit verschiedener Synthesemethoden wurde mithilfe von „First ‐ principles“ ‐ Rechnungen geprüft, um mögliche Wege zu solchen Borschichten auszuloten. [ABSTRACT FROM AUTHOR]

Boron synthesis, in theory: Although two‐dimensional boron sheets have attracted considerable interest because of their theoretically predicted properties, synthesis of such sheets remains a challenge. The feasibility of different synthetic methods for two‐dimensional boron sheets (see picture; red) was assessed using first‐principles calculations, possibly paving the way towards its application in nanoelectronics. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of atomic fracture mechanisms in 2D materials is essential for their practical applications, yet this knowledge is currently limited. To address this gap, an aberration‐corrected scanning transmission electron microscope (STEM) to induce new cracks in suspended monolayer transition metal dichalcogenides (TMDs) using broad electron beam illumination, is employed. During characterization, a low‐dose electron beam to avoid irradiation damage, allowing to observe the atomic fracture behavior in these materials, is utilized. The STEM experiments reveal a novel atomic fracture pattern along the zigzag direction, resulting in a distribution where half of the chalcogen atoms (S or Se) adhered to the molybdenum‐terminated (Mo‐T) edge and the other half to the chalcogen‐terminated (S‐T or Se‐T) edge. Density functional theory (DFT) calculations suggest that this fracture mode produces a pair of edges with the lowest formation energy. Additionally, molecular dynamics (MD) simulations support the observed fracture behavior under a mixed mechanical loading mode of “I+III” with both in‐plane and out‐of‐plane stress, originating from the ultrathin nature and nonplanar deformation in suspended 2D materials. This research offers new insights for the development of 2D fracture mechanics and is pivotal for designing devices incorporating 2D materials. [ABSTRACT FROM AUTHOR]

There is great interest in developing advanced electrical conductors with higher conductivity, lighter weight, and higher mechanical strength than copper (Cu). One promising candidate is copper‐graphene (Cu‐Gr) composite, which is hypothesized to have a higher electrical conductivity than Cu. In this work, it is shown that this is not true, supported by state‐of‐the‐art first‐principles calculations of electron transport. Particularly, contrary to the belief that graphene in the composite is more conductive than pristine Cu, it is less conductive due to increased scattering despite increased carrier concentration. On the other hand, it is found that compressive strain along the (111) plane increases the conductivity, which is confirmed experimentally, while tensile strain has little effect. The work offers new insights into understanding and developing advanced conductors. [ABSTRACT FROM AUTHOR]

Heterogeneous electrocatalysis lies at the center of various technologies that could help enable a sustainable future. However, its complexity makes it challenging to accurately and efficiently model at an atomic level. Here, we review emerging atomistic methods to simulate the electrocatalytic interface with special attention devoted to the components/effects that have been challenging to model, such as solvation, electrolyte ions, electrode potential, reaction kinetics, and pH. Additionally, we review relevant computational spectroscopy methods. Then, we showcase several examples of applying these methods to understand and design catalysts relevant to green hydrogen. We also offer experimental views on how to bridge the gap between theory and experiments. Finally, we provide some perspectives on opportunities to advance the field. [ABSTRACT FROM AUTHOR]

Electrolytes play a critical role in stabilizing highly reactive lithium‐metal anodes (LMAs) and high‐voltage cathodes for rechargeable lithium‐metal batteries (LMBs). Localized high concentration electrolytes (LHCEs) have achieved remarkable success in the context of LMBs. However, the state‐of‐the‐art LHCEs are based on LiFSI salt, which is prohibitively expensive. Here, the utility of low‐cost LiPF6 salt in localized saturated electrolytes (LSEs) with a series of solvents and diluents in LMBs with cobalt‐free LiNiO2 cathode is systematically explored. Experimental and theoretical analyses reveal that the unique solvation structure formed not only changes the distribution of solvents and anions but also alters the atom–atom distances within them, leading to different reduction and oxidation stabilities compared to low‐concentration electrolytes. In addition, LSEs help form LiF‐rich interphase layers on the LMA and LiNiO2 cathode, protecting the electrodes from degradation during cycling. Different LSEs also lead to differences in lithium plating morphology and impedance buildup during cycling, impacting the performance of LMBs. The solvent and diluent must be carefully selected for compatibility with a lithium salt when developing LHCEs and LSEs for LMBs. [ABSTRACT FROM AUTHOR]

Two-dimensional electrocatalysts have attracted great interest in recent years for renewable energy applications. However, the atomistic mechanisms are still under debate. Here we review the first-principles studies of the atomistic mechanisms of common 2D electrocatalysts. We first introduce the first-principles models for studying heterogeneous electrocatalysis then discuss the common 2D electrocatalysts with a focus on N doped graphene, single metal atoms in graphene, and transition metal dichalcogenides. The reactions include hydrogen evolution, oxygen evolution, oxygen reduction, and carbon dioxide reduction. Finally, we discuss the challenges and the future directions to improve the fundamental understanding of the 2D electrocatalyst at atomic level. [ABSTRACT FROM AUTHOR]

The valance of Mo is critical for FeMo cofactor in ambient ammonia synthesis. However, the valence effect of Mo has not been well studied in heterogeneous nanoparticle catalysts for electrochemical nitrogen reduction reaction (NRR) due to the dissolution of Mo as MoO42− in alkaline electrolytes. Here, a MoO2+x catalyst enriched with surface Mo6+ is reported. The Mo6+ is stabilized by a native oxide layer to prevent corrosion and its speciation is identified as (MoO3)n clusters. This native layer with Mo6+ suppresses the hydrogen evolution significantly and promotes the activation of nitrogen as supported by both experimental characterization and theoretical calculation. The as‐prepared MoO2+x catalyst shows a high ammonia yield of 3.95 µg mgcat−1h−1 with a high Faradaic efficiency of 22.1% at −0.2 V versus reversible hydrogen electrode, which is much better than the MoO2 catalyst with Mo6+ etched away. The accuracy of experimental results for NRR is confirmed by various control experiments and quantitative isotope labeling. [ABSTRACT FROM AUTHOR]

ZnO and SnO2 are wide bandgap semiconductors, which have great potential for UV detectors, light emitting diodes, and other optoelectronic devices. The performance of these devices is significantly affected by exciton binding energies of oxides. Although bandgaps of ZnO and SnO2 are similar, their exciton binding energies differ by a large amount, because it was reported experimentally that the exciton binding energy of SnO2 is 130 meV, which is higher than that of ZnO with 60 meV. On the other hand, because ZnO has higher ionicity and a large overlap of electrons and hole wavefunctions, it is expected that it should have larger exciton binding energy than that of SnO2 [Dvorak et al., Phys. Rev. Lett. 110, 016402 (2013)]. Therefore, there is a controversy for relative magnitudes of the exciton binding energy between SnO2 and ZnO. Here, based on accurate GW + Bethe–Salpeter equation calculations, we clarify that the exciton binding energy of SnO2 is less than that of ZnO, following the general rule; therefore, more experimental study should be carried out to verify our predictions. We expect that this fundamental understanding of the relative magnitude of exciton binding energies will be useful for prospective applications of ZnO and SnO2 in optoelectronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) semiconductors have shown great potential in electronic applications. One of their key properties is the intrinsic mobility of the charge carriers (electrons/holes) at room temperature, the understanding of which is still limited partially due to the challenges in experimentally probing the intrinsic properties without the external interference. First-principles methods, enabled by recent developments, are ideal for calculating and understanding the intrinsic mobility. In this paper, we review the first-principles methods for calculating the intrinsic carrier mobility of 2D semiconductors, and the progress in understanding the underlying physical factors governing the mobility. Finally, we provide some perspectives on further research directions. [ABSTRACT FROM AUTHOR]

Electroreduction of N 2 to ammonia (NH 3) under ambient conditions, driven by renewable electricity, provides a promising alternative to the Haber-Bosch process and can reduce over 90% of CO 2 emissions via NH 3 synthesis. However, this process suffers from the shortage of efficient electrocatalysts. Herein, we report the size-dependent catalytic activity of Mo nanoparticles (NPs) in the size range of 1–10 nm for the electrochemical synthesis of NH 3 from N 2 and H 2 O. Current density drastically increases as Mo size decreases. The mass activity of 1.5 nm Mo NPs reaches 27.6 μg h−1 mg−1 cat. , which is higher than that of the best noble metal catalyst under comparable reaction conditions. Density functional theory (DFT) calculations show that the enhanced activity with a small size is due to an increase in edge sites between (110) and (100) surfaces. This condition weakens the binding of ∗NH 2 and lowers the energy barrier of the second NH 3 desorption at the determining step. Image 1 • Exceptional size-dependent catalytic activity over Mo nanoparticles is revealed. • The synthesized 1.5 nm Mo nanoparticles possess an outstanding ENRR activity. • The edge sites between (110) and (100) surfaces increase for ultra-small Mo nanoparticles. [ABSTRACT FROM AUTHOR]

Designing cost‐effective and efficient electrocatalysts plays a pivotal role in advancing the development of electrochemical water splitting for hydrogen generation. Herein, multifunctional active‐center‐transferable heterostructured electrocatalysts, platinum/lithium cobalt oxide (Pt/LiCoO2) composites with Pt nanoparticles (Pt NPs) anchored on LiCoO2 nanosheets, are designed towards highly efficient water splitting. In this electrocatalyst system, the active center can be alternatively switched between Pt species and LiCoO2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Specifically, Pt species are the active centers and LiCoO2 acts as the co‐catalyst for HER, whereas the active center transfers to LiCoO2 and Pt turns into the co‐catalyst for OER. The unique architecture of Pt/LiCoO2 heterostructure provides abundant interfaces with favorable electronic structure and coordination environment towards optimal adsorption behavior of reaction intermediates. The 30 % Pt/LiCoO2 heterostructured electrocatalyst delivers low overpotentials of 61 and 285 mV to achieve 10 mA cm−2 for HER and OER in alkaline medium, respectively. [ABSTRACT FROM AUTHOR]

Designing cost‐effective and efficient electrocatalysts plays a pivotal role in advancing the development of electrochemical water splitting for hydrogen generation. Herein, multifunctional active‐center‐transferable heterostructured electrocatalysts, platinum/lithium cobalt oxide (Pt/LiCoO2) composites with Pt nanoparticles (Pt NPs) anchored on LiCoO2 nanosheets, are designed towards highly efficient water splitting. In this electrocatalyst system, the active center can be alternatively switched between Pt species and LiCoO2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Specifically, Pt species are the active centers and LiCoO2 acts as the co‐catalyst for HER, whereas the active center transfers to LiCoO2 and Pt turns into the co‐catalyst for OER. The unique architecture of Pt/LiCoO2 heterostructure provides abundant interfaces with favorable electronic structure and coordination environment towards optimal adsorption behavior of reaction intermediates. The 30 % Pt/LiCoO2 heterostructured electrocatalyst delivers low overpotentials of 61 and 285 mV to achieve 10 mA cm−2 for HER and OER in alkaline medium, respectively. [ABSTRACT FROM AUTHOR]

Solvents play an essential role in many areas of chemistry and is the cornerstone of understanding reactivity in solution‐phase reactions. Solvent effects have been widely observed in intercalation reactions; however, understanding of the influence of solvents on the thermodynamics and kinetics remains largely elusive in intercalation chemistry. Now, the solvent‐dependent kinetics of ferrocene intercalation into a layered vanadyl phosphate (VOPO4⋅2 H2O) host is presented, with a special focus on primary alcohols. From methanol to 1‐hexnaol, the intercalation rate peaks in 1‐propanol (80 times faster than the slowest case in methanol). Similar kinetics of exfoliation are also found in these solvents without ferrocene. The correlation between intercalation and exfoliation is understood at atomic level by DFT calculations, which reveal the role of pre‐intercalated solvent molecules play in intralayer interactions, interlayer expansion, and layer sliding. [ABSTRACT FROM AUTHOR]

Solvents play an essential role in many areas of chemistry and is the cornerstone of understanding reactivity in solution‐phase reactions. Solvent effects have been widely observed in intercalation reactions; however, understanding of the influence of solvents on the thermodynamics and kinetics remains largely elusive in intercalation chemistry. Now, the solvent‐dependent kinetics of ferrocene intercalation into a layered vanadyl phosphate (VOPO4⋅2 H2O) host is presented, with a special focus on primary alcohols. From methanol to 1‐hexnaol, the intercalation rate peaks in 1‐propanol (80 times faster than the slowest case in methanol). Similar kinetics of exfoliation are also found in these solvents without ferrocene. The correlation between intercalation and exfoliation is understood at atomic level by DFT calculations, which reveal the role of pre‐intercalated solvent molecules play in intralayer interactions, interlayer expansion, and layer sliding. [ABSTRACT FROM AUTHOR]

The 2-D materials possess application perspective in semiconductor logic devices owing to their bonding free surface carrier transport. However, the scaling transistor width-induced edge issues have significantly limited their surface transport within the lateral direction, leading to effective mass increasing, and bandgap fluctuations. Therefore, it is important to find a novel 2-D material with both excellent surface transport and immunity to edge effect. In this paper, inspired by the recently discovered tellurene and its unique Te-Te bonds, the edge effect on the transport characteristics of tellurene is studied theoretically in the form of tellurene nanoribbons (TNRs). Among the four edge types, three of them exhibit semiconducting characteristic owing to the unique bonding property of Te. Simulation results demonstrate that the tetragonal edges (TEs) in zigzag TNRs (ZTNRs) almost have no influence on surface transport, resulting in minimized bandgap and effective mass variations, compared to that of graphene nanoribbons, and Si and Ge nanowires. Transport behaviors of the TE-ZTNRs are investigated using a metal–oxide–semiconductor transistor model and a multiscale simulation flow, with the calculated current densities exceeding $\textsf {1}$ mA/ $\mu \text{m}$ and the on–off ratios over $10^{\textsf {11}}$. Based on the results, an explicit prediction that the TE-ZTNRs are competitive candidates for nanoscale transistor materials is proposed. [ABSTRACT FROM AUTHOR]

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease. [Display omitted] [ABSTRACT FROM AUTHOR]

Rationally designed electrodes with a high specific surface area, conductivity, and ion diffusion rate are essential for high performance supercapacitors. Hereby, we report the construction of a three-dimensional (3D) N- and S-codoped graphene hydrogel with abundant in-plane pores (NS-HGH). In NS-HGH, its highly interconnected network structure largely restrains the restacking of the graphene sheets, offering a specific surface area of as high as 317 m 2  g −1 . The abundant intimate graphene sheet-sheet contacts and in-plane pores created provide efficient electron transport pathways and ion transport pathways, respectively. The dopants of N and S heteroatoms further improve the porosity and conductivity of the resultant NS-HGH. With these characteristics, the NS-HGH electrode exhibits a high specific capacitance of 320.0 F g −1  at 1 A g −1 and retains 96.4% of the initial capacitance upon 10000 potential cycles at 10 A g −1 . Whiles, the supercapacitors made from the NS-HGH electrodes deliver an impressive gravimetic energy density of 24.7 Wh kg −1  at 1 A g −1 . To understand the high capacitive performance of the NS-HGH, we further performed first-principle simulations. It is revealed that heteroatom doping offers additional capacitance to NS-HGH because its density of states (DOS) near the Fermi energy level can be largely increased as a result of abundant polarized sites produced. These results suggest that NS-HGH shows great potential for practical application. [ABSTRACT FROM AUTHOR]

Abstract: Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing picture for the conversion of N2 into NH3. However, electrocatalytic NRR mainly relies on metal‐based catalysts, and it remains a grand challenge in enabling effective N2 activation on metal‐free catalysts. Here we report a defect engineering strategy to realize effective NRR performance (NH3 yield: 8.09 μg h−1 mg−1cat., Faradaic efficiency: 11.59 %) on metal‐free polymeric carbon nitride (PCN) catalyst. Illustrated by density functional theory calculations, dinitrogen molecule can be chemisorbed on as‐engineered nitrogen vacancies of PCN through constructing a dinuclear end‐on bound structure for spatial electron transfer. Furthermore, the N−N bond length of adsorbed N2 increases dramatically, which corresponds to “strong activation” system to reduce N2 into NH3. This work also highlights the significance of defect engineering for improving electrocatalysts with weak N2 adsorption and activation ability. [ABSTRACT FROM AUTHOR]

Abstract: Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing picture for the conversion of N2 into NH3. However, electrocatalytic NRR mainly relies on metal‐based catalysts, and it remains a grand challenge in enabling effective N2 activation on metal‐free catalysts. Here we report a defect engineering strategy to realize effective NRR performance (NH3 yield: 8.09 μg h−1 mg−1cat., Faradaic efficiency: 11.59 %) on metal‐free polymeric carbon nitride (PCN) catalyst. Illustrated by density functional theory calculations, dinitrogen molecule can be chemisorbed on as‐engineered nitrogen vacancies of PCN through constructing a dinuclear end‐on bound structure for spatial electron transfer. Furthermore, the N−N bond length of adsorbed N2 increases dramatically, which corresponds to “strong activation” system to reduce N2 into NH3. This work also highlights the significance of defect engineering for improving electrocatalysts with weak N2 adsorption and activation ability. [ABSTRACT FROM AUTHOR]

The expansion of urban areas and the increase in the number of buildings and urbanization characteristics, such as roads, affect the meteorological environment in urban areas, resulting in weakened pollutant dispersion. First, this paper uses GIS (geographic information system) spatial analysis technology and landscape ecology analysis methods to analyze the dynamic changes in land cover and landscape patterns in Chengdu as a result of urban development. Second, the most appropriate WRF (Weather Research and Forecasting) model parameterization scheme is selected and screened. Land-use data from different development stages in the city are included in the model, and the wind speed and temperature results simulated using new and old land-use data (1980 and 2015) are evaluated and compared. Finally, the results of the numerical simulations by the WRF-Chem air quality model using new and old land-use data are coupled with 0.25° × 0.25°-resolution MEIC (Multi-resolution Emission Inventory for China) emission source data from Tsinghua University. The results of the sensitivity experiments using the WRF-Chem model for the city under different development conditions and during different periods are discussed. The meteorological conditions and pollution sources remained unchanged as the land-use data changed, which revealed the impact of urban land-use changes on the simulation results of PM2.5 atmospheric pollutants. The results show the following. (1) From 1980 to 2015, the land-use changes in Chengdu were obvious, and cultivated land exhibited the greatest changes, followed by forestland. Under the influence of urban land-use dynamics and human activities, both the richness and evenness of the landscape in Chengdu increased. (2) The microphysical scheme WSM3 (WRF Single–Moment 3 class) and land-surface scheme SLAB (5-layer diffusion scheme) were the most suitable for simulating temperatures and wind speeds in the WRF model. The wind speed and temperature simulation results using the 2015 land-use data were better than those using the 1980 land-use data when assessed according to the coincidence index and correlation coefficient. (3) The WRF-Chem simulation results obtained for PM2.5 using the 2015 land-use data were better than those obtained using the 1980 land-use data in terms of the correlation coefficient and standard deviation. The concentration of PM2.5 in urban areas was higher than that in the suburbs, and the concentration of PM2.5 was lower on Longquan Mountain in Chengdu than in the surrounding areas. [ABSTRACT FROM AUTHOR]

Vertically aligned black reduced porous SnO 2 nanosheets were succesfully developed via vacancy engineering for the first time, which simultaneously realized the promoted conductivity and active sites, hence leading to the efficient and durable CO 2 RR to formate. • Black reduced porous SnO 2 nanosheets were prepared via thermal annealing. • Our electrocatalyst possessed metallic conductivity and high density of active sites. • The maximum Faradaic efficiency of 92.4% for formate was obtained in CO 2 RR. • Stable Faradaic efficiency of 90 ± 2% was maintained under -0.6 to -1.1 V vs. RHE. • Oxygen vacancies in SnO 2 decreased the energy barrier of HCOO−* and HCOOH* for CO 2 RR. The great bottleneck that lies in CO 2 reduction reaction (CO 2 RR) electrocatalysts is to simultaneously enhance their conductivity and density of active sites. Herein, we developed a black reduced porous SnO 2 nanosheets electrocatalyst that enabled possessing both metallic conductivity and high density of active sites via vacancy engineering. The black reduced porous SnO 2 nanosheets showed high activity and selectivity for CO 2 RR to formate, with maximum Faradaic efficiency (FE) of 92.4% at the low overpotential of 0.51 V and stable FE of 90 ± 2% in the large potential range from -0.6 to -1.1 V vs. reversible hydrogen electrode (RHE). Density functional theory (DFT) calculations indicated that the introduction of oxygen vacancy increased carrier density and lowered the adsorption of HCOO - * and HCOOH by 0.29 and 0.17 eV, respectively, accounting for the improved CO 2 RR to formate performance. [ABSTRACT FROM AUTHOR]

In article number 1903192, Hongli Zhu and co-workers design a cost-effective and scalable surface modification method using graphite felt to enhance the mass transfer and reaction kinetics in aqueous flow batteries. This treatment increases the electrode surface area, improves the electrode hydrophilicity, and provides a sufficient number of oxygen groups, resulting in enhanced kinetics and electrolyte accessibility at the electrode-electrolyte interface. Electrochemical exfoliation, hydrophilicity, hydrophilicity, kinetic, redox flow battery, surface treatment. [Extracted from the article]

A scalable and efficient process to modify electrodes with enhanced mass transfer and reaction kinetics is critical for redox flow batteries (RFBs). For the first time, this work introduces electrochemical exfoliation as a surface modification method of graphite felt (GF) to enhance the mass transfer and reaction kinetics in RFBs. Anion intercalation and subsequent gas evolutions at room temperature for one minute expand the graphite layers that increase the electrode surface area. Meanwhile, sufficient oxygen functional groups are introduced to the electrode, resulting in enhanced reaction kinetics and improved hydrophilicity. Further, spin‐polarized density functional theory is employed to reveal the role of oxygen functional groups in accelerating the vanadium redox reaction. Benefitting from sufficient oxygen groups, larger surface area, and superior wettability, the as‐prepared exfoliated GF (E‐GF) shows exceptional electrocatalytic activity with minimized overpotential, higher volumetric capacity, and improved energy efficiency. The redox flow battery assembled with the E‐GF electrode delivers voltage and energy efficiencies of 89.72% and 86.41% at the current density of 100 mA cm−2, respectively. Remarkably, compared to the traditional GF treatment method, the elimination of the high temperature and long‐time treatment processes make this approach much more energy and time efficient, scalable, and affordable for large‐scale manufacturing. [ABSTRACT FROM AUTHOR]

In article number 1803990, Deji Akinwande, Yuebing Zheng, and co‐workers develop a simple and low‐power optical technique – optothermoplasmonic nanolithography – for the versatile optical patterning of a variety of two‐dimensional (2D) atomically thin materials. The patterning arises from the thermal oxidation and sublimation of 2D materials at the laser‐directed localized thermoplasmonic hotspots. Optothermoplasmonic nanolithography opens a new avenue for on‐demand optical fabrication of 2D‐based electronic and photonic devices. [ABSTRACT FROM AUTHOR]

Since the first discovery of graphene, 2D materials are drawing tremendous attention due to their atomic thickness and superior properties. Fabrication of high‐quality micro‐/nanopatterns of 2D materials is essential for their applications in both nanoelectronics and nanophotonics. In this work, an all‐optical lithographic technique, optothermoplasmonic nanolithography (OTNL), is developed to achieve high‐throughput, versatile, and maskless patterning of different atomic layers. Low‐power (≈5 mW µm−2) and high‐resolution patterning of both graphene and MoS2 monolayers is demonstrated through exploiting thermal oxidation and sublimation at the highly localized thermoplasmonic hotspots. Density functional theory simulations reveal that Au nanoparticles reduce the formation energy (≈0.6 eV) of C monovacancies through bonding between undercoordinated C and Au, leading to a significant Au‐catalyzed graphene oxidation and a reduction of the required laser operation power. Programmable patterning of 2D materials into complex and large‐scale nanostructures is further demonstrated. With its low‐power, high‐resolution, and versatile patterning capability, OTNL offers the possibility to scale up the fabrication of nanostructured 2D materials for many applications in photonic and electronic devices. Optothermoplasmonic nanolithography (OTNL) is developed for low‐power, high‐throughput, and on‐demand patterning of different 2D materials. The variable high‐resolution patterns on 2D monolayers are fabricated through exploiting thermal oxidation and sublimation at the localized thermoplasmonic hotspots. OTNL offers the scalable fabrication of nanostructured 2D materials for various applications. [ABSTRACT FROM AUTHOR]

Atomic hydrogen exists ubiquitously in graphene materials made by chemical methods. Yet determining the effect of hydrogen on the electrochemical performance of graphene remains a significant challenge. Here we report the experimental observations of high rate capacity in hydrogen-treated 3-dimensional (3D) graphene nanofoam electrodes for lithium ion batteries. Structural and electronic characterization suggests that defect sites and hydrogen play synergistic roles in disrupting sp2 graphene to facilitate fast lithium transport and reversible surface binding, as evidenced by the fast charge-transfer kinetics and increased capacitive contribution in hydrogen-treated 3D graphene. In concert with experiments, multiscale calculations reveal that defect complexes in graphene are prerequisite for low-temperature hydrogenation, and that the hydrogenation of defective or functionalized sites at strained domain boundaries plays a beneficial role in improving rate capacity by opening gaps to facilitate easier Li penetration. Additional reversible capacity is provided by enhanced lithium binding near hydrogen-terminated edge sites. These findings provide qualitative insights in helping the design of graphene-based materials for high-power electrodes. [ABSTRACT FROM AUTHOR]