Transmission Electron Research Articles

Immobilisation of zero-valent silver-decorated jujube activated carbon (Ag0/JAC) on polyester fabric for catalytic reduction of 4-nitrophenol

ABSTRACT Heterogeneous catalytic technology is highly effective for pollutant degradation, but achieving recyclability remains a critical challenge. In this study, a recyclable Ag/AC photocatalyst coating was developed on polyester fabric using a dip-coating method, where polyester fabric served as a support due to its adaptability, durability, handling ease and enhanced pollutant adsorption. This research focuses on the immobilisation in-situ of Ag nanoparticles on jujube kernel activated carbon (JAC) modified polyester fabric (Ag/JAC@PEF) for the reduction n of 4-Nitrophenol (4-NP). The process involves coating the fabrics (PEF) with jujube kernel activated carbon through sonication. The produced Ag, JAC@PET, and Ag/JAC@PEF have been characterised utilising various physicochemical methods, such as X-ray diffraction (XRD), Fourier Transformed Infra-Red (FTIR), trans mission electron microscopy (TEM), scanning electron microscopy (SEM), and Thermogravimetric analysis (TGA), Raman spectroscopy, and N2 adsorption – desorption isotherms. Catalytic tests revealed that the coated fabrics exhibited excellent catalytic performance for the reduction of 4-NP. All coated fabrics successfully facilitated the reduction of 4-NP using NaBH4 as the reducing agent. Among them, the 10%Ag/5%JAC@PET sample, with a 6 cm2 surface area, exhibited the highest catalytic efficiency, achieving a reduction rate constant of 1.2457 min− 1 and nearly 98% removal within 60 minutes. This high performance is attributed to the favourable combination and close contact between Ag0 and AC in the catalyst, as well as the porous structure of the polyester fabric, which facilitated pollutant adsorption while providing recovery potential. Additionally, the Ag/JAC@PEF catalyst exhibited exceptional stability over several reaction cycles using a 6 cm2 surface area and 10% silver nanoparticles. This study highlights the potential of polyester fabric-based coatings for practical applications in catalyst recovery.

Synthesis of Carbon and Gold Nanoparticles in Ionic Liquid Crystals: Structural Properties and Electrical Behavior for Electro‐Optical Sensors

ABSTRACTThe structural and electrical properties of ionic metal‐alkanoate nanocomposites obtained based on a cadmium octanoate matrix with individual carbon and gold nanoparticles (NPs) as well as their combination are studied. Carbon and gold NPs were chemically synthesized within the smectic A phase of Cd+2(C7H15COO−)2, which served as a well‐ordered nanoreactor. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) data provide information on NPs location and allow the estimation of the sizes of the synthesized NPs inside the glassy liquid crystalline matrix. It is shown that the size and shape of the NPs were precisely controlled during synthesis, resulting in highly stable and organized nanocomposites. The electrical characteristics were studied in a wide temperature range corresponding to different phase states of the nanocomposites. We compared the electrical properties of both pure matrix and nanocomposites with carbon and gold NPs to identify the potential of the nanocomposite materials for designing new sensor structures. Notably, the nanocomposites exhibited anisotropic conductivity, highlighting the structural anisotropy of the material. In addition, using NPs allows fine‐tuning of the electrical properties of a metal‐alkanoate host matrix. The obtained nanocomposites open prospects for the development of electro‐optical sensors with high sensitivity and specificity that can be used to detect a variety of chemical and physical parameters including temperature, composition of substances, and environment.

Degradation of Rhodamine B dye using the mesoporous material KIT-6/TiO2 photocatalyst obtained by in situ anchoring method.

In this study, a novel synthesis approach was employed to create the KIT-6/TiO2 photocatalyst with different ratios of Si/Ti. The results of the X-ray diffraction revealed that incorporating TiO2 with the anatase phase maintained the mesoporous structure of KIT-6 (Korean Institute of Technology 6). The scanning electron microscope and transmission electron microscope images exhibited unobstructed mesopores, validating their anchoring within the internal structure of the support. Furthermore, nitrogen adsorption-desorption studies confirmed the presence of TiO2 within the pores. X-ray photoelectron spectroscopy (XPS) analysis corroborated the successful incorporation of TiO2, showing the presence of Ti4+ and Ti3+ species, with Ti3+ indicating the presence of oxygen vacancies that enhance photocatalytic performance. Photodegradation efficiency was assessed for Rhodamine B, achieving 95% and 86.5% for KIT-6/TiO2 (Si/Ti = 25) and KIT-6/TiO2 (Si/Ti = 75), respectively. The molar ratio Si/Ti = 25 exhibited higher activity, which can be attributed to a better distribution of active sites, as confirmed by the measurement of turnover frequency (TOF = 2.0 × 10-2min-1). The stability of the KIT-6/TiO2 (Si/Ti = 25) has also been investigated, and stable performance in recycling photocatalytic reactions was obtained after four cycles of use. The scavengers used indicated that the superoxide anion radical (•O2-) and electron (e-) were the major active species. This study successfully demonstrated the incorporation of TiO2 into the walls of mesoporous materials using the ISA method, achieving high photocatalytic efficiency. Moreover, this method enabled superior performance with a reduced amount of photocatalyst compared to a pure TiO2 sample.

Conductive materials enhance anaerobic membrane bioreactor (AnMBR) treating waste leachate at high organic loading rates.

The treatment of landfill leachate using anaerobic membrane bioreactors (AnMBRs) often faces challenges such as poor removal efficiency, low methane yield and membrane fouling. This study applied AnMBRs with incrementally adding conductive materials to enhance the treatment of landfill leachate under high organic loading rates(35kg COD/(m3∙d)). With 50g/L activated carbon, COD removal percentages and methane yield increased to 81.03±2.12% and 0.34±0.01m³ CH₄/kg COD, respectively. The addition of conductive materials dramatically increased EPS content of the sludge, which not only enhanced inter-microbial electron transmission but also increased the sludge's biological activity. The primary membrane fouling type for AnMBRs was cake layer, with Ca being the main inorganic foulant, and humic substances and proteins being the principal organic foulants. Combined cleaning methods effectively removed membrane foulants, resulting in total membrane flux recovery rates of higher than 96.5%. The conductive materials stimulated the enrichment and synergistic collaboration of acid-producing bacteria and methanogenic archaea.

Effects of an electrospun Janus structure on enhanced UV resistance performance.

Thermoplastic polyurethane (TPU) fabrics often possess good mechanical, waterproofing, and breathability properties. However, the resistance of TPU to excessive ultraviolet (UV) irradiation is poor and often does not meet the UV resistance requirements of fabrics. Electrospun nanofibers with a side-by-side structure can combine the advantages of different materials. Therefore, in this study, a series of Janus composite nanofiber membranes with side-by-side structures were prepared by eccentric electrospinning using polyacrylonitrile (PAN), titanium dioxide (TiO2), and TPU as raw materials. The Janus structure of the nanofibers was evident in scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. Wettability and breathability tests showed that the nanofiber membranes exhibited waterproofing and breathability properties. The Janus composite nanofiber membrane with 1 wt% titanium dioxide TiO2 exhibited a UV-protection factor (UPF) as high as 1962 and a UV transmittance of less than 2.5%, with the amount of TiO2 added being proportional to the UV resistance. Additionally, the UV resistance of the nanofiber membranes did not decrease substantially after seven days of immersion in solutions at different pH values. Finally, this study analyzed the mechanism by which the Janus structure enhanced the UV resistance. The UV light was reflected, refracted, and absorbed many times on the crescent side with excellent UV-absorption performance, which greatly improved the UV resistance of the membrane.

Larval instar‐dependent hemocytes in specialist herbivore Cydalima perspectalis fed on Buxus hyrcana and Buxus microphylla

AbstractThe boxwood moth, Cydalima perspectalis Walker (Lepidoptera: Crambidae), as invasive specialist species in Iran has caused considerable damage in endemic forest stands of Buxus hyrcana Pojark since 2016. Host plant species can alter herbivore–plant interactions through the quantitative and qualitative changes of hemocytes even within a specialist herbivore. To determine the hemocyte variations on different host plants across larval development, the third and sixth instar larvae of C. perspectalis fed on B. hyrcana (native boxwood) and B. microphylla Sieb. and Zucc. (introduced nonnative boxwood) were compared. Total (THC) and differential (DHC) hemocyte count were determined using light, phase‐contrast, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on results, six types of hemocytes were recognized in hemolymph including prohemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), oenocytoides (OEs) and spherulocytes (SPs) as well as unknown elongated quadrangular cells (elongocytes [ELs], the term has been first employed here) with obvious and distinguishable nuclei which were observed by the SEM and TEM microscopy. The ELs were rectangular or trapezoidal in shape, and the largest cells in hemolymph—their length varied from 14.00 to 15.73 μm. Our results showed that the total number of hemocytes (THC) significantly increased across larval development. Moreover, host plant species significantly affected total hemocyte count where the THC of sixth instar larvae on B. microphylla (2561.00 ± 10.60 cell/mm3) was significantly higher than on B. hyrcana (2440.00 ± 51.50 cell/mm3). The differential hemocyte count (DHC) profile study showed that GRs along with PLs were the most abundant cells in the hemolymph irrespective of larval instar and host plant species. Furthermore, the GRs% and ELs% increased throughout the larval development on both host plants, while a significant reduction of PLs% was recorded from third instar to sixth instar during the larval stage on two Buxus species. Apart from larval instar, host plant species had a significant effect on DHC of C. perspectalis. Despite higher total hemocyte number when fed on B. microphylla, the PLs% and ELs% were significantly higher in sixth‐instar larvae fed on B. hyrcana compared with B. microphylla. Oppositely, the percentage of GRs was 17% less in larvae reared on B. hyrcana than on B. microphylla. As hemocyte types are responsible for different immune functions, these findings on instar‐ and host plant‐dependent variation in their relative abundance would be critical to understand the immune response of this specialist herbivore.

The role of sulfidated zero-valent iron in enhancing anaerobic digestion of waste activated sludge.

Zero-valent iron (ZVI) has been confirmed in enhancing methane production by improving interspecies electron transfer during anaerobic digestion (AD) of waste activated sludge (WAS). In this study, we suppose that sulfidated zero-valent iron (S-ZVI), a semiconductor material, has better property of electron transfer in AD process. Based on two-phase anaerobic digestion process, nitrite and S-ZVI were used separately for improving acidogenic phase and methanogenic phase of anaerobic sludge digestion. Based on XRD and XPS, Fe(Ⅱ)-O and Fe(Ⅲ)-O were substituted by Fe(Ⅱ)-S and Fe(Ⅲ)-S after ZVI sulfidation, which increased the electric conductivity of S-ZVI. Nyquist plot and Tafel corrosion curve showed that the sulfidation treatment can reduce impedance of electronic transmission. The results showed that the addition of S-ZVI increased methane production by 24.22% compared with ZVI alone. The addition of S-ZVI increased the relative abundance of Actinobacteria in R3(Raw+S-ZVI) and R6(NO2-+S-ZVI), enhancing the activity of microbial in anaerobic sludge digestion. The relative abundance of Acidobacteriota, Synergistota, WPS-2, Firmicutes, Caldisericota, and Gampylobactenota have changed markedly, and facilitated the activity of acidogenic microbes to produce more biodegradable organic matter, further boosting methane production. The findings of in-situ formation of S-ZVI in R5 anaerobic digestion saves the economic cost of S-ZVI preparation, which will be helpful for the extensive application of this technology.

Chiral induction at the nanoscale and spin selectivity in electron transmission in chiral methylated BEDT-TTF derivatives.

Great efforts have been made in the last few decades to realize electronic devices based on organic molecules. A possible approach in this field is to exploit the chirality of organic molecules for the development of spintronic devices, an applicative way to implement the chiral-induced spin selectivity (CISS) effect. In this work we exploit enantiopure tetrathiafulvalene (TTF) derivatives as chiral inducers at the nanoscale. The aim is to make use of TTF's well-known and unique semiconducting properties, to be expressed in the fields of enantio-selectivity and the chiral-induced spin selectivity (CISS) effect. The experimental results shown in this paper further demonstrate how chirality and spin are deeply interrelated, as foreseen within the CISS effect theory, paving the way for the application of TTF derivatives in the field of spintronics. In this work, we demonstrate that tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) (1) behaves as an efficient spin filter, as evidenced by magneto-atomic force microscopy (mc-AFM) measurements. Additionally, it is shown to be effective in transferring chirality to CdS/CdSe core-shell nanoparticles, as inferred from the analysis of circularly resolved photoluminescence spectra. This makes 1 a promising candidate for a variety of applications, ranging from plasmonics to quantum computing.

Novel metal-organic framework coated with chitosan-κ-carrageenan as a platform for curcumin delivery to cancer cells.

Metal-organic frameworks (MOFs) have shown great promise as pH-responsive drug delivery systems, with considerable potential for targeted cancer therapy. In this study, we synthesized a novel curcumin-loaded MOF, named UWO-2 (CUR@UWO-2), and developed its biocomposite form, CS-κ-Cr/CUR@UWO-2, by coating it with chitosan (CS) and κ-carrageenan (κ-Cr). Structural analysis through powder X-ray diffraction (PXRD) confirmed the successful synthesis of UWO-2 and the incorporation of CUR within the MOF structure. X-ray photoelectron spectroscopy (XPS) analysis revealed two distinct peaks at approximately 1021.15 eV and 1044.23 eV, corresponding to the Zn 2p₃/₂ and Zn 2p₁/₂ states, respectively. These peaks confirm the presence of the expected Zn2+ oxidation state in UWO-2, further validating its successful synthesis. Brunauer-Emmett-Teller (BET) analysis demonstrated a significant decrease in surface area (367.4 m2/g) and pore volume (0.296 cm3/g), validating the entrapment of CUR within the UWO-2 MOF structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that UWO-2 particles are spherical with a smooth surface, while CUR@UWO-2 exhibited a larger particle size, indicating successful curcumin loading. Thermogravimetric analysis (TGA) indicated enhanced thermal stability due to CUR loading, while swelling experiments revealed increased water absorption at neutral pH, supporting effective drug release under physiological conditions. Biodegradation studies showed sustained degradation of CUR@UWO-2 in the presence of lysozyme, confirming its suitability for in vivo applications. The drug delivery system achieved 21.9 % drug loading and 75.1 % encapsulation efficiency. Drug release experiments indicated accelerated release under acidic conditions, with the Korsmeyer-Peppas model identifying Fickian diffusion as the primary release mechanism. Cytotoxicity assessments showed increased cell death with CUR@UWO-2, enhanced by the synergistic effect of UWO-2, while the CS-κ-Cr coating enabled controlled, prolonged curcumin release. Confocal microscopy confirmed cellular uptake of CUR, underscoring the potential of the biocomposite for tumor-targeted chemotherapy applications in cancer treatment. This study highlights the potential of CUR@UWO-2, especially in its biocomposite form, for tumor-targeted drug delivery applications.

A brief review on the progress of MXene-based catalysts for electro- and photochemical water splitting for hydrogen generation.

The development and generation of affordable and highly efficient energy, particularly hydrogen, are one of the best approaches to address the challenges posed by the depletion of non-renewable energy sources. Hydrogen energy, as a green and ecosystem-friendly source with zero carbon emission, can be generated through various methods, including water splitting (HER/OER) via either photo- or electrocatalytic reactions. To implement these reactions effectively in practical applications, it is highly desirable to develop extremely efficient and cost-effective catalytic materials that are comparable to contemporary catalysts. MXenes, a family of newly discovered 2D transition metal carbides, nitrides, or carbonitrides with surface termination groups, such as -OH, -O, and -F, have emerged as promising materials and substrates for photo- and electrocatalytic applications due to their unique characteristics. These include excellent conductivity provided by the transition metals, hydrophilic nature imparted by the surface termination groups, high mechanical stability, fast electronic transmission and extremely high surface area-to-volume ratios. In this review, we provide detailed insights into the synthesis, properties, and catalytic applications of MXenes. We systematically outline the photo- and electrocatalytic water splitting reactions carried out by various MXene-based heterostructures, supported by experimental data. A thorough deliberation on the structure-activity associations of reported catalysts and a basic understanding of the electrocatalytic applications of MXenes are also included. Furthermore, we offer an insight into the upcoming tasks, challenges, prospects and new research strategies for MXenes in water splitting applications. A noteworthy recognition of the design and optimization of extremely efficient MXene-based catalysts in water splitting applications is therefore offered in this review.

Self-Assembly Strategy for Synthesis of WO3@TCN Heterojunction: Efficient for Photocatalytic Degradation and Hydrogen Production via Water Splitting.

Herein, a WO3@TCN photocatalyst was successfully synthesized using a self-assembly method, which demonstrated effectiveness in degrading organic dyestuffs and photocatalytic evolution of H2. The synergistic effect between WO3 and TCN, along with the porous structure of TCN, facilitated the formation of a heterojunction that promoted the absorption of visible light, accelerated the interfacial charge transfer, and inhibited the recombination of photogenerated electron-hole pairs. This led to excellent photocatalytic performance of 3%WO3@TCN in degrading TC and catalyzing H2 evolution from water splitting under visible-light irradiation. After modulation, the optimal 3%WO3@TCN exhibited a maximal degradation rate constant that was twofold higher than that of TCN alone and showed continuous H2 generation in the photocatalytic hydrogen evolution. Mechanistic studies revealed that •O2- constituted the major active species for the photocatalytic degradation of tetracycline. Experimental and DFT results verified the electronic transmission direction of WO3@TCN heterojunction. Overall, this study facilitates the structural design of green TCN-based heterojunction photocatalysts and expands the application of TCN in the diverse photocatalytic processes. Additionally, this study offers valuable insights into strategically employing acid regulation modulation to enhance the performance of carbon nitride-based photocatalysts by altering the topography of WO3@TCN composite material dramatically.

Study on the Coarsening Behavior of Interphase Precipitates and Random Precipitates in Steel Under the High-Temperature Environment of Fire

In the domain of fire-resistant steels, the characteristics of precipitates significantly influence material properties. This study developed a novel heat treatment protocol to concurrently achieve both interphase precipitation and random precipitation. Samples were subjected to isothermal treatments at various temperatures and durations, while techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to thoroughly analyze the coarsening behavior of the two types of precipitate and reveal their thermal stability differences. The results show that the growth and coarsening rates of interphase precipitates are substantially lower than random precipitates. Coarsening kinetics analysis reveals that the radius of random precipitates follows a 1/3 power law with time at 600 °C and 650 °C, whereas the radius of interphase precipitates adheres to a 1/6 power law at 600 °C and a 1/5 power law at 650 °C. Furthermore, interphase precipitation demonstrates excellent size uniformity, which hinders the formation of a concentration gradient, thereby reducing the coarsening rate and enhancing thermal stability. After prolonged tempering treatment, interphase precipitation maintains a higher strengthening contribution than random precipitation. This study provides novel insights and theoretical foundations for the design and development of fire-resistant steels.

Comparative In Vitro Study of Sol-Gel-Derived Bioactive Glasses Incorporated into Dentin Adhesives: Effects on Remineralization and Mechanical Properties of Dentin.

To overcome limitations of dentin bonding due to collagen degradation at a bonded interface, incorporating bioactive glass (BAG) into dentin adhesives has been proposed to enhance remineralization and improve bonding durability. This study evaluated sol-gel-derived BAGs (BAG79, BAG87, BAG91, and BAG79F) and conventional melt-quenched BAG (BAG45) incorporated into dentin adhesive to assess their remineralization and mechanical properties. The BAGs were characterized by using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy for surface morphology. The surface area was measured by the Brunauer-Emmett-Teller method. X-ray diffraction (XRD) analysis was performed to determine the crystalline structure of the BAGs. Adhesive surface analysis was performed after approximating each experimental dentin adhesive and demineralized dentin by using FE-SEM. The elastic modulus of the treated dentin was measured after BAG-containing dentin adhesive application. The sol-gel-derived BAGs exhibited larger surface areas (by 400-600 times) than conventional BAG, with BAG87 displaying the largest surface area. XRD analysis indicated more pronounced and rapid formation of hydroxyapatite in the sol-gel BAGs. Dentin with BAG87-containing adhesive exhibited the highest elastic modulus. The incorporation of sol-gel-derived BAGs, especially BAG87, into dentin adhesives enhances the remineralization and mechanical properties of adhesive-dentin interfaces.

Electromechanics of the Molecule-Electrode Interface and Interface-Mediated Effects in Single-Molecule Junctions.

The molecule-electrode interface can regulate both the efficiency and pathways of electron transport through single-molecule junctions (SMJs). The electromechanics of the interface has proven crucial in exposing the underlying mechanisms of electron transmission through SMJs, providing a theoretical base and practical guidance for designing and constructing functional molecular devices. Here we encompass several currently developed methodologies for investigating the electromechanics of molecule-electrode interface and provide an account of their application in elucidating the effects of the molecule-electrode interface on electron transport properties of SMJs. This review will offer a comprehensive picture and new insights into developing single-molecule electromechanical devices and the progression of devices' mechanical stability toward large-scale integration.

Unveiling the Electrocatalytic Performances of the Pd-MoS2 Catalyst for Methanol-Mediated Overall Water Splitting

Herein, this work elucidates the synthesis of the Pd-MoS2 catalyst for application in methanol-mediated overall water splitting. The scanning electron microscope (SEM) and transmission electron microscope (TEM) pictures offer an exciting nanostructured shape of the Pd-MoS2, depicting a high surface area. Further, high-resolution TEM (HRTEM) pictures confirm the lattice plane (100), lattice spacing (0.26 nm), and hexagonal crystal structure of the Pd-MoS2. Moreover, high-angle annular dark-field (HAADF) images and related color maps disclose the Mo, S, and Pd elements of the Pd-MoS2. The Pd-MoS2 catalyst exhibits lower overpotentials of 224.6 mV [methanol-mediated hydrogen evolution reaction (MM-HER)] at −10 mA cm−2 and 133 mV [methanol-mediated oxygen evolution reaction (MM-OER)] at 10 mA cm−2. Further, the Pd-MoS2 illustrates noteworthy stability for 15.5 h for MM-HER and 18 h for MM-OER by chronopotentiometry test. Excitingly, the Pd-MoS2∥Pd-MoS2 cell reveals a small potential of 1.581 V compared to the MoS2∥MoS2 cell (1.648 V) in methanol-mediated overall water splitting. In addition, the Pd-MoS2∥Pd-MoS2 combination reveals brilliant durability over 18 h at 10 mA cm−2.

Influence of the Applied WC/C and CrN + WC/C Coatings on the Surface Protection of X2CrNi18-9 Cavitation Generators

The purpose of this paper is to investigate the impact of the applied WC/C and CrN + WC/C protective coatings applied using various PVD methods as protection for cavitation generators operating in an environment of intense cavitation wear. In order to carry out planned tasks, special devices generating a cavitation environment have been designed and manufactured. As part of this study, an analysis of the surface of cavitation generators, both before applying the coatings and with the applied protective PVD coatings, and also before and after operation in a cavitation environment, was carried out using the following research techniques: stereoscopic microscopy, scanning electron microscopy, transmission microscopy, XRD, and confocal microscopy. Despite the use of corrosion-resistant steels as a result of the cavitation environment, this causes surface material wear, especially in the area of the through holes. This is due to the fact that there are no protective coatings inside the through hole. Moreover, it was found that, for the tested steel with multilayer CrN + WC/C coatings, there were significantly fewer cavitation defects both on the surface of the material and on the edge of through holes, which indicates that the use of these multilayer coatings can significantly extend the service life of structural elements operating in such environmental conditions. Based on the conducted research tests, it was proven that the applying protective coatings significantly reduce the wear of the surfaces of the tested cavitation generators, thus allowing the use of cheaper steels, not resistant to corrosion, e.g., P265GH steel, which is five times cheaper than austenitic steel. The P265GH steel is used for structural elements in the heating, petrochemical, energy, food, and chemical industries, as well as for structural elements in the aviation, shipbuilding, and many other industries, and, thus, it is possible to reduce the costs associated with the operation of this construction solution in industrial conditions.

Two-Dimensional Nonvolatile Valley Spin Valve.

A spin valve represents a well-established device concept in magnetic memory technologies, whose functionality is determined by electron transmission, controlled by the relative alignment of magnetic moments of the two ferromagnetic layers. Recently, the advent of valleytronics has conceptualized a valley spin valve (VSV)─a device that utilizes the valley degree of freedom and spin-valley locking to achieve a similar valve effect without relying on magnetism. In this study, we propose a nonvolatile VSV (n-VSV) based on a two-dimensional (2D) ferroelectric semiconductor where resistance of n-VSV is controlled by a ferroelectric domain wall between two uniformly polarized domains. Focusing on the 1T″ phase of MoS2, which is known to be ferroelectric down to a monolayer and using density functional theory combined with quantum transport calculations, we demonstrate that switching between the uniformly polarized state and the state with oppositely polarized domains separated by a domain wall results in a resistance change of as high as 107. This giant VSV effect occurs due to transmission being strongly dependent on matching (mismatching) the valley-dependent spin polarization in the two domains with the same (opposite) ferroelectric polarization orientations, when the chemical potential of 1T″-MoS2 lies within the spin-split valleys. The proposed n-VSV can be employed as a functional device for high-performance nonvolatile valleytronics.

Hammerhead Shark‐Inspired Microvillus‐Structured Ionic Elastomers for Wet Gas Sensing Based on Solvated Ion Transport

AbstractWater molecules are ubiquitous disruptors of conventional gas sensing materials, often leading to diminished sensing performance in materials that are reliant on electronic signal transmission. This creates the pressing need for efficient gas sensing materials with anti‐humidity interference properties. Here, a hammerhead shark‐inspired microvillus‐structured ionic elastomer based on ionic signal transmission in nanoconfined space is constructed by incorporating ionic liquids into a polymer matrix. The ionic elastomers with optimized microvillus structure demonstrated a 1.68‐fold higher response than that of the flat ones, short response time (9 s) toward 30 ppm triethylamine (TEA), excellent selectivity and low limit of detection (LOD) (104.56 ppb). Such sensing performance serves as a proof‐of‐concept for effectively combining solvated ion transport in nanoconfined space with microvillus structure design to develop advanced sensing systems. With such sensing materials, an evident response (23.52%), a similar response time (12 s), low LOD (498.05 ppb), and long‐term stability (at least 30 days) are achieved at the relative humidity of 70%. Mechanistic investigations revealed that effective transport of solvated ions is facilitated after sequential water and TEA surroundings while the microvillus structure significantly enhanced gas transport. Furthermore, the utility of such a sensing system is demonstrated in shrimp decay monitoring under wet conditions.

Morphology and Formation of Chrysanthemum-like Pearlite in 100Mn13 Steel During Aging Treatment

The morphology and microstructure of pearlite formed in 100Mn13 high-carbon high-manganese steel aged, respectively, at 525 °C and 650 °C after 1050 °C water toughening treatment were observed and analyzed by a scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that some pearlite colonies are chrysanthemum-like and are composed of M7C3 lamellae and ferrite lamellae, maintaining an orientation relationship (OR) of (3¯312)M7C3‖(0 2¯ 4)α, [4 0 1]M7C3‖[5 2 1]α. Moreover, the lamellae in pearlite colonies with chrysanthemum-like morphology are distributed in an emanative way, where there are protrusions and branches at the growth frontier. A growth physical model describing the growth process of chrysanthemum-like pearlite is proposed.

Interfacial Synergism in NiMoO4/FeOOH Heterostructure for Enhanced Alkaline Oxygen Evolution and Urea Oxidation.

FeOOH with excellent catalytic properties for oxygen evolution and also considered to be a true active site has attracted great interest in recent years. However, the intrinsic low conductivity limits its catalytic performance. Herein, a one-dimensional core-shell NiMoO4/FeOOH heterojunction with high OER activity and stability was developed. At current densities of 10 and 100 mA cm-2, low overpotentials of 194 and 266 mV are need to drive oxygen evolution, meanwhile, the electrode exhibits high catalytic kinetics with small Tafel slopes of 53.4 mV dec-1 and excellent stability over 100 hours. Further analysis showed that the ultrathin FeOOH layer (~5 nm) uniformly covered the surface of NiMoO4 nanorods, acting as an active species and facilitating the surface change transfer to the interior. The internal NiMoO4 cores, on the other hand, provides reliable electron transmission as a highly conductive medium, and can effectively overcome the low conductivity of FeOOH. DFT calculations further manifest the strong electronic interactions between NiMoO4 and FeOOH species. The NiMoO4 core serves as mass transport of active materials is beneficial to tune the adsorption energy of OH- on the surface of electrocatalysts.