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The discovery of ferromagnetism in monolayer transition metal halides exemplified by CrI3 has opened a new avenue in the field of two-dimensional (2D) magnetic materials, and more such 2D materials are waiting to be explored. Herein, using an unbiased structure search combined with first-principles calculations, we have identified a novel CuCl2 monolayer, which exhibits not only intrinsic ferromagnetism but also auxetic mechanical properties originating from the interplay of lattice and Cu–Cl tetrahedron symmetries. The predicted Curie temperature of CuCl2 reaches ∼47 K, and its ferromagnetism is associated with the strong hybridization between the Cu 3d and Cl 3p states in the configuration. Moreover, upon biaxial tensile strain or carrier doping, the CuCl2 monolayer can be converted from ferromagnetic to non-magnetic and from half-metal to metal. These properties endow this CuCl2 monolayer with great potential for applications in auxetic/spintronic nanodevices.

A novel protein-based polymer memristor is synthesized by a polymerization reaction using silk fibroin protein (SFP) and 2-isocyanatoethyl methacrylate. The analogue-type protein-based memristor demonstrates that more than 32 conductance levels are impressively obtained and outstandingly maintained for 4 months. This work provides a new horizon for high performance analogue computing systems.

The information technologies have been increasing exponentially following Moore's law over the past decades. This has fundamentally changed the ways of work and life. However, further improving data process efficiency is facing great challenges because of physical and architectural limitations. More powerful computational methodologies are crucial to fulfill the technology gap in the post-Moore's law period. The memristor exhibits promising prospects in information storage, high-performance computing, and artificial intelligence. Since the memristor was theoretically predicted by L. O. Chua in 1971 and experimentally confirmed by HP Laboratories in 2008, it has attracted great attention from worldwide researchers. The intrinsic properties of memristors, such as simple structure, low power consumption, compatibility with the complementary metal oxide-semiconductor (CMOS) process, and dual functionalities of the data storage and computation, demonstrate great prospects in many applications. In this review, we cover the memristor-relevant computing technologies, from basic materials to in-memory computing and future prospects. First, the materials and mechanisms in the memristor are discussed. Then, we present the development of the memristor in the domains of the synapse simulating, in-memory logic computing, deep neural networks (DNNs) and spiking neural networks (SNNs). Finally, the existent technology challenges and outlook of the state-of-art applications are proposed.

Understanding excitonic behavior in light absorption and recombination process is urgently needed to regulate luminescent properties of two-dimensional (2D) perovskite; however, such information is...

Alcohol has a potential health risk to human health, so it is important to realise the rapid detection of alcohols. Based on this, the nano Na2Mg(CO3)2 was prepared by a simple hydrothermal method to establish a cataluminescence (CTL) gas sensor for alcohols. The Na2Mg(CO3)2with highly purified quality was characterised by scanning electron microscope, energy dispersive spectroscopy and the powder X-ray diffraction. The results show that the nano Na2Mg(CO3)2 is a peony-like substance with a large surface area, which will be beneficial to produce ultra-weak chemiluminescence reaction between the detector and the material. The peony-like Na2Mg(CO3)2 has good CTL response to alcohols (methanol, ethanol, n-propanol and n-butanol), showing high selectivity. The response time of Na2Mg(CO3)2 for four alcohols is between 1 and 2 s, which indicate that the material has the advantage of rapid response. The limit of detection of four alcohols defined as 3 N/S is about 7.91, 4.75, 6.69 and 8.10 mg/l, respectively. The optimum reaction conditions of the gas sensor based on nano Na2Mg(CO3)2 are mild and this nanomaterial can be used for alcohol detection.

It is well known that the reprogrammable device is one of the important needs for circuit design. In this paper, nanolayered TiO2 and maple leaves (ML) are combined to form a functional layer (TiO2...

Complex three-dimensional nanosheet structure of ZnxFeyO was prepared by highly stable co-sputtering oblique angle deposition. Scanning electron microscopy was employed to observe surface morphology evolution of ZnxFeyO with different Fe concentrations. X-ray diffraction was employed to analyze compositions of ZnO, ZnFe2O4, and ZnFe2O4/Fe2O3 with Fe doping. Furthermore, specific nanostructures of ZnxFeyO decreased band gap and increased visible-light absorption ability. The ZnFe2O4/Fe2O3 sample exhibited higher photocatalytic efficiency than those of other films for the degradation of methylene blue. Addition of Fe led to the enhancement of photoelectrochemical properties of ZnFe2O4/Fe2O3 compared to pure ZnO and Fe2O3, and photocurrent response of ZnFe2O4/Fe2O3 was ~10 times than that of pure ZnO at constant potential of −0.2 V (vs. Ag/AgCl).

The memristive effect become a bio-electronics research focus with the development of sustainable systems and the application of multifunctional electronic devices. In this paper, the natural Lophatherum gracile Brongn (LGB) was employed as active layer to prepare Ag/LGB/fluorine-doped tin oxide (FTO) bio-memristor. Further, different doping ratios nano silver powders (Ag nanoparticle) were doped into LGB functional layers at 0 wt%, 0.2 wt%, 0.33 wt%, 1.0 wt%, 2.0 wt%, 10.0 wt% and 20.0 wt%. It is found that the capacitive-coupled memristive performance of the Ag/Ag-doped-LGB/FTO devices was markedly changed. Finally, it is confirmed that Ag ions transferring and Ag filament formation under the applied voltage are responsible for capacitive-coupled memristive behavior. This research has revealed the realization of capacitive-coupled memristive effect of bio-memristor, which opens a new way to achieve multifunctional performance for electronic device.

The resistive random access memory (RRAM) based on resistive switching effect has considered to be the most advanced next generation memory, in which the switching direction determines the order of reading-writing. In this work, the rare-earth metal Er2O3 was used as functional layer, and Ag and indium-tin-oxide (ITO) are selected as top and bottom electrode to fabricate resistive switching device. Further, it is observed that the switching direction and memory window of resistive switching device can be regulated by exchanging top and bottom electrode. Moreover, the complementary switching memory behavior in Ag/Er2O3/ITO/Er2O3/Ag structure was also observed. Through mechanism analysis, it is expected that the barrier changes and metal-ions oxidation-reduction should be responsible for the conversion of switching direction and regulation of memory window. This work opens up a way to the development of next generation new concept memory.

A novel technology (co-sputtering oblique angle deposition) was used for fabricating W-doped Bi 2 O 3 films. After further annealing at 500 °C, the surface morphologies and microstructures of the films were characterized by scanning electron microscopy and X-ray diffraction. With increase in the sputtering current of W target in co-sputtering process, the surface morphology of W-doped Bi 2 O 3 films changed significantly. The mechanism of morphology evolution was systematically studied. The optical properties of W-doped Bi 2 O 3 films such as band gap and photocatalytic performance were also investigated. The results indicate that this co-sputtering oblique angle deposition technology is a promising new method for investigating the nanostructures photocatalytic and other performance of doped materials.

With the increasing demand for green electronic devices, the electronic devices based on biomaterials have been developed vigorously. Especially, the biomemristive memory device, which is prepared using biomaterials as functional layers, has shown great potential and application value in green and sustainable bioelectronic devices. In this work, the collagen, for the first time, was extracted from pigskin and utilized as the intermediate insulating layer for constructing two biomemoristive memory devices with Ag/Bio-film/ITO and Ag/Bio-film/Ti structures, in which it can be found that the high-resistance state/low-resistance state resistance ratio is ∼10 when the ITO was used as bottom electrode but it can be increased to ∼100 by using Ti as bottom electrode. Through further data analysis, we propose a mechanism of ions' redox and defect state filling to explain the switching mechanism of these devices. Our work indicates that the natural biomaterials which were derived from animals can be used to prepare the degradable and biocompatible bioelectronics devices.

Recently fabricated two-dimensional (2D) black phosphorene (BP) is considered to be a promising optoelectronic sheet, but its applications are hindered by the poor stability in air. Thus, it is des...

Since conventional graphite-based anode possesses a low capacity, seeking for high-capacity anode candidates becomes significant for constructing emerging Li-ion batteries. Herein, we present a composite anode prepared using a hydrothermal method, which consists of dense NiO nanoflakes in situ growing on reduced graphene oxide (rGO) sheets. The rGO sheets within the NiO/rGO composite provide a conductive frame that enables rapid charge transfer, while the in situ anchoring of NiO nanoflakes on rGO reduces the agglomeration. We found that the appropriate loading of NiO in the composite is also significant. The NiO/rGO composite anode exhibits a high capacity of 1068 mAh g−1 after 100 cycles at 0.1 A g−1. In addition, the capacity remains 870 mAh g−1 when the current density is increased to a high rate of 2 A g−1, indicating a good rate performance for potential applications.

A bio-memristor, which was prepared using the bio-materials as basic components, has being become the focus of research owing to the potential application as medical diagnosis in biomedical field. Herein, an environmentally-friendly and sustainable bio-memristor device with Ag/walnut skin (WS)/ITO structure was fabricated, in which an obvious and reliably repeated rectangular current–voltage characteristic curve is observed. Our result shows that the WS, an useless bio-material, can be used to fabricate electronic devices after proper processing. Finally, the memory mechanism based on the conductive filament mode associated the capacitance effect is ascribed. This work has opened a new way to exploit the next generation bio-electronic device with advantages of environmentally-friendly, sustainable and pollution-free.

Pressure is one of the most effective fundamental elements that can change the bonding patterns of materials and lift the reactivity of elements, leading to the synthesis of unconventional compounds with fascinating properties. Using unbiased structure search method based on particle-swarm optimization algorithm in combination with density functional theory calculations, we investigate the stable compositions of iron-boride (Fe B) system at pressures ranging from 0 to 300 GPa. We obtained the high pressure Fe B phase diagram with six pressure-induced stable compositions (Fe3B, Fe2B, FeB, Fe2B3, FeB2, FeB4) under their desired pressure range. In their stable structure, it is found that the coordination number of Fe atoms, the Fe B spherical packing efficiency, the number of B B bonds for each B atom, and the calculated hardness almost increase with the increasing of B content. Through the characterization of bonds in these stable Fe B structures, it reveals that the ionic gradually become weak while the covalence becomes strong as B content increasing. Due to this, we attribute the excellent mechanical properties of the FeB2 and FeB4 structure to the more strong covalent bonds dominantly by providing coulomb repulsion between the B atoms. Our current results expand the knowledge and provide further insight into the pressure-induced structure and properties of Fe B compounds.

A resistive switching random access memory (RRAM) has occupied great scientific and industrial interest for next-generation data storage technology because of its advantages of nonvolatile behavior, low power consumption, high density, rapid writing/erasing speed, and simple operating system. In this work, the wide spectrum with self-colored ZnO layers on the Ti foil is obtained by varying the sputtering time, and the colors of these ZnO films can be tuned by a MoS2 layer covering. Further, an existence of resistive switching (RS) memory and negative differential resistance (NDR) state in MoS2/ZnO heterojunction devices was demonstrated, in which the bright yellow Ag/MoS2/ZnO/Ti device shows the best performance with long time endurance. This work opens up an opportunity for exploration of the multifunctional components in future electronic applications.

Recently spotlighting on lithium disulfide (Li2S2) as an intermediate product of a promising high capacity lithium–sulfur (Li S) battery, a structure of P42/mnm had been proposed for understanding the existence of Li2S2 in Li S battery. Here using first-principles unbiased CALYPSO structure searching calculations, we uncovered a new energetically favored structural phase (P21/c) of Li2S2, being more stable than the P42/mnm structure at above 2.78 GPa. This predicted P21/c structure possess a similar quasi-molecular S2 and Li atoms in the interstice of S2 with P42/mnm structure, but having a denser polyhedral packing (LiS6) with Li atoms six-fold coordination in contract to the four-fold coordinated LiS4 polyhedron of P42/mnm. Further, a calculated discharge voltage of 2.34 V was obtained for 2Li+ + 2e− + Li2S2 →2Li2S and comparable to that of P42/mnm. Adopting CI-NEB method, we calculated the diffusion barrier and diffusion coefficient of Li ions with a high diffusion coefficient of 5.98 × 10−2/cm2 s−1. This character reflects that it can acts as an intermediate product like as P42/mnm in a Li S battery. This work has a value in exposing the pressure–induced phase of Li2S2 and enriching the views for understanding in Li S batteries.

Photo-induced novel effect in a material with multiple physical properties has highly important potential applications in the photo-electric multifunctional electronic devices. In this work, the BiFeO3/ZnO bilayer films were sequentially prepared by magnetron sputtering method, which displays an obvious photo-modulated conversion between resistive switching (RS) memory and negative differential resistance (NDR) effect. Through theoretical analysis and simulation calculation, suggesting the NDR effect can be attributed to the inner electric field and the efficiently separated photogenerated electrons and holes under light-irradiation in the interface of the BiFeO3/ZnO p–n heterojunctions, while the RS memory behavior can be attributed to the formation of oxygen vacancies assisted Ag conductive filaments. This work opens up a new way to preparation a multifunction electronic device with photo-modulated conversion between RS memory and NDR effect for potential applications in optical electrical bifunctional devices, electronic information and optical quantum computers, and so on.

NiO nanostructures and film were deposited on Cu foil using radiofrequency (RF) magnetron sputtering with oblique and glancing angle deposition technology. The modified CU foil was used as an anode material for a Li ion battery without binder or conductive additives. The electrochemical properties of the NiO electrodes depended on their porosity, which varied with the angle of incidence of the target with respect to the normal substrate surface. The NiO electrodes showed a well aligned nanorod structure when deposited at a glancing angle of 85°. The optimal NiO nanorod electrodes exhibited a reversible lithium capacity of 710 mAh g−1 at a current rate of 0.5C and 270 mAh g−1 at a current rate of 20 C. Furthermore, after 1000 ultra-long cycles at 2.0C, the capacity of the NiO nanorod electrode was retained at about 500 mAh g−1, which was ~ 70% of theoretical capacity. The high performance and ultra-long life cycle of the NiO nanorod electrodes was attributed to super-structures with macroporosity.

Ultra-flexible egg albumen paper with a permittivity of 15–21, which is an improvement of nearly 300% compared with native egg albumen, is synthesized. Wearable protein-based memristor arrays exhibit excellent memory behavior and memory logic gate functionality under dual photoelectric control.

A device with the lateral structure of Ag|MnOx|Ag was developed using a single MnOx nanorod. The device showed a typical resistor property under dry ambience, while it demonstrated the reversion between resistor and memristor under moisture ambience. Memory logic functions including logic gates and displays were feasible under the dual input of electric and moisture signals.

Despite much progress in the semiconductor-integrated circuit technology for resistive switching memory, it is still hard to implement on the extremely complex neuromorphic networks. Resistive switching memory with multilevel operations and multi-state behaviors shows its inherent potential in neural networks. Herein, a resistive switching memory device with the structure of Ag/(C7H7O4N)n/F-doped SnO2 (FTO) showed a unique capacitance effect and negative differential resistance (NDR) states; also, a non-zero-crossing hysteresis loop and multistate resistances in terms of programming and erasing processes were feasible. Uniquely, a pH-controlled behavior was observed for the first time during the self-colored switching layer of (C7H7O4N)n extracted from a lichen plant. The chemical potential gradients generating an emf in the interfaces were responsible for this effect, and the ion transportation in the switching layer and the related redox reaction under the bias voltage played dominant roles in the multi-state memory behaviors and remarkable NDR states. This device provides a promising application in the neuromorphic artificial synapse as well as a selection of memory states.

The ever-growing demand for sustainable and renewable power sources has led to the development of novel materials for photocatalytic water splitting, but enhancing the photocatalytic efficiency remains a core problem. Herein, we report a conceptual effective and experimental confirmed strategy for SnO2 quantum dot (QD) interspersed multiphase (rutile, anatase) TiO2 nanorod arrays (SnO2/RA@TiO2 NRs) to immensely enhance the carrier separation for highly efficient water splitting by merging simultaneously the QD, multiphase, and heterojunction approaches. Under this synergistic effect, a doping ratio of 25% SnO2 QD interspersed into multiphase TiO2 NRs exhibited a superior optical adsorption and excellent photocurrent density (2.45 mA/cm2 at 1.0 V), giving rise to a largely enhanced incident light to current efficiency in the UV region (45-50%). More importantly, this material-based device can act as power supply with a voltage of ∼2.8 V after illumination, which can automatically self-recharge by reacting with oxygen vacancy and water molecule to realize reuse. The current study provides a new paradigm about heightening the carrier separation extent of QD interspersed multiphase heterojunctions, fabricating a new solar-energy-converting material/device, and achieving a highly photocatalytic water splitting/self-charging battery-like application.

Using biomaterial-constructed resistive switching memory devices has attracted great attention for the potential application in advanced electronic components because of their variety of advantages, such as low cost, sustainability, environment-friendly, and so on. In this work, after a series of treatments, an edible mushroom as an intermediate insulating material was assembled into an Ag/biofilm/metal structure, in which the metals such as Al, Cu, Ag, and Ti were chosen as the bottom electrode to explore in-depth physical mechanisms. The transmission mechanism of resistive switching memory behavior in an Ag/biofilm/metal device was studied in detail. It was found that the redox of hydroxyl-assisted Ag filaments could be easily formed on an inactive metal bottom electrode through the mushroom film by redox reaction under applied voltage. This work provides an ingenious potential application in wearable, flexible, sustainable, and environment-friendly biologically resistive random-access memories.

High dimensionality and fading memory for in-sensor reservoir computing are achieved via two-dimensional memristors., The dynamic processing of optoelectronic signals carrying temporal and sequential information is critical to various machine learning applications including language processing and computer vision. Despite extensive efforts to emulate the visual cortex of human brain, large energy/time overhead and extra hardware costs are incurred by the physically separated sensing, memory, and processing units. The challenge is further intensified by the tedious training of conventional recurrent neural networks for edge deployment. Here, we report in-sensor reservoir computing for language learning. High dimensionality, nonlinearity, and fading memory for the in-sensor reservoir were achieved via two-dimensional memristors based on tin sulfide (SnS), uniquely having dual-type defect states associated with Sn and S vacancies. Our in-sensor reservoir computing demonstrates an accuracy of 91% to classify short sentences of language, thus shedding light on a low training cost and the real-time solution for processing temporal and sequential signals for machine learning applications at the edge.

A high-slew-rate, low-power, CMOS, rail-to-rail buffer amplifier for large flat-panel-display (FPD) applications is proposed. The major circuit of the output buffer is a rail-to-rail, folded-cascode, class-AB amplifier which can control the tail current source using a compact, novel, adaptive biasing scheme. The proposed output buffer amplifier enhances the slew rate throughout the entire rail-to-rail input signal range. To obtain a high slew rate and low power consumption without increasing the static current, the tail current source of the adaptive biasing generates extra current during the transition time of the output buffer amplifier. A column driver IC incorporating the proposed buffer amplifier was fabricated in a 1.6-&mu, m 18-V CMOS technology, whose evaluation results indicated that the static current was reduced by up to 39.2% when providing an identical settling time. The proposed amplifier also achieved up to 49.1% (90% falling) and 19.9 % (99.9% falling) improvements in terms of settling time for almost the same static current drawn and active area occupied.

High-energy-density secondary batteries are required for many applications such as electric vehicles. Lithium-sulfur (Li-S) batteries are receiving broad attention because of their high theoretical energy density. However, the large volume change of sulfur during cycling, poor conductivity, and the shuttle effect of sulfides severely restrict the Li-storage performance of Li-S batteries. Herein, we present a novel core-shell nanocomposite consisting of a sulfur core and a hydrogel polypyrrole (PPy) shell, enabling an ultra-high sulfur content of about 98.4% within the composite, which greatly exceeds many other conventional composites obtained by coating sulfur onto some hosts. In addition, the void inside the core-shell structure effectively accommodates the volume change; the conductive PPy shell improves the conductivity of the composite; and PPy is able to adsorb polysulfides, suppressing the shuttle effect. After cycling for 200 cycles, the prepared S@void@PPy composite retains a stable capacity of 650 mAh g-1, which is higher than the bare sulfur particles. The composite also exhibits a fast Li ion diffusion coefficient. Furthermore, the density functional theory calculations show the PPy shell is able to adsorb polysulfides efficiently, with a large adsorption energy and charge density transfer.

The content of volatile organic compounds (VOCs) in the atmosphere will endanger the health and safety of human beings which makes it very important to develop a simple and rapid method for the determination of gas pollutants. Based on this, a new type of gas sensor was proposed for the detection of trichloroethylene in air. PEG200/ZnO nanocomposite were prepared by hydrothermal method. The materials were characterized by scanning electron microscope, X-ray energy spectrum and fourier infrared spectrum. The high selectivity of the materials was verified by using the cataluminescence (CTL) intensity of 9 kinds of VOCs on the surface of the materials as a reference. The results show that trichloroethylene can produce CTL response on the surface of PEG200/ZnO nanocomposite. Temperature, air flow rate and detector concentration all have certain effects on the CTL intensity. By comparing the CTL intensity under different reaction conditions, it is found that the suitable temperature and air flow rate are 120 °C, 180 mL/min and there is a good linear relationship between the relative CTL intensity and the concentration of the detected substance (y = 28.588 x - 285.56, R=0.9593). The gas sensor has the advantage of rapid response, and trichloroethylene can produce the maximum CTL on the surface of the material within 3 ~ 5 s.

The resistance change of an insulator or semiconductor under applied current or voltage is defined as resistive switching effect, which is a significative physical performance in the exploit of new concept nonvolatile resistance random access memory (RRAM). In our work, the g-C3N4 powder was firstly fabricated by calcination method, and continuously a device with Ag/g-C3N4/FTO structure was prepared using drop-coated g-C3N4 powder to form a film onto FTO. It can be observed that the as-prepared cell exhibits an excellent resistive switching memory characteristic (HRS/LRS resistance ratio can be reached to ~ 52) and good reliability under applied voltage window of 4.0 V. Finally, it is believed that the space charge limited conduction is appropriate to understanding such the memory behavior.

The mechanism of resistance switching memory effect has always been a focused scientific topic. In this work, a new resistance conversion mechanism is put forward in a resistance switching device with sandwich structure, in which the Cu2ZnSnSe4 (CZTSe) is used as active layer and the F-doped SnO2 (FTO) and Al-doped ZnO (AZO) acts the top and bottom electrode, respectively. Through further in-depth study, an optimal memory effect in the FTO/CZTSe/AZO device is observed when the thickness of CZTSe film is ∼200 nm (dCZTSe = 200 nm). Finally, the memory characteristics of the resistance switching device is clarified in detail by using a physical model based on the tunneling of carrier at the Schottky barrier which are formed on the FTO/CZTSe and CZTSe/AZO interfaces.

Resistance random access memory (RRAM) is a promising memory technology in the applications of memory device. Herein, the amorphous TiO2 thin film was grown onto titanium (Ti) foil by anodic oxidation. Further, the Ag/TiO2/Ti sandwich structure device was prepared, which displays a resistive switching memory effect with a high HRS/LRS resistance ratio with ∼27 at room temperature when the TiO2 film was oxidized ∼5 min. Finally, the formation/rupture models of Ag conductive filaments are suggested to explain the resistive switching memory behavior. This work open a new way for preparing the RRAM device for memory applications in the future.

The resistance random access memory (RRAM) based on biomaterials has great potential application in the sustainable electronic devices with the advantages of being sustainable, green, and environment-friendly, and it can offer a potential route for developing bio-RRAM devices, which would be a competitive bench in development of multipurpose memory devices. In our work, the banana peel, an ubiquitous useless waste, is introduced as an intermediate insulating material to preparing resistive switching memory device with Ag/Banana peel/Ti structure, in which the superior switching memory performance with a lager high resistance state/low resistance state resistance ratio and long retention characteristics are revealed. Moreover, the coexistence of memristor effect, capacitance effect, and negative differential resistance phenomenon are observed in our device. The repeatable nonvolatile resistive switching memory behaviors are attributed to the redox properties of metal cations contained in biomaterials.

The resistive switching effect is a fascinating physical phenomenon in the development of next-generation nonvolatile memory devices. In this work, the resistive switching memory behaviors of metal/In2S3/Mo/glass devices have been investigated. We observed that the top electrode materials can affect the resistive switching memory behaviors of such devices. We have also found that the devices represent an outstanding memory behavior with the largest HRS/LRS resistance ratio (storage window) when using Au as the top electrode.

In this work, a flexible resistive switching memory device based on ZnO film was fabricated using a foldable Polyethylene terephthalate (PET) film as substrate while Ag and Ti acts top and bottom electrode. Our as-prepared device represents an outstanding nonvolatile memory behavior with good "write-read-erase-read" stability at room temperature. Finally, a physical model of Ag conductive filament is constructed to understanding the observed memory characteristics. The work provides a new way for the preparation of flexible memory devices based on ZnO films, and especially provides an experimental basis for the exploration of high-performance and portable nonvolatile resistance random memory (RRAM).

In this work, a resistive switching memory device, in which niobium (Nb) inserted into magnesium diboride (MgB2) multilayer constructed heterojunctions, was prepared by vacuum sputtering at 400 °C. Furthermore, a continuously enlarge memristor memory effect was observed in Ti/(MgB2/Nb)n/MgB2/Ti (n = 0, 1, 2, 3) devices with the increasing of the inserted Nb layers numbers for the first time. Finally, a model of Schottky barrier based on interfaces of Ti/MgB2 and Nb/MgB2 are used to explain the memory characteristics.

The recent discovery of non-volatile resistive-switching memory is a promising phenomenon for the semiconductor industry and electronic device technology. In our work, CaWO4 nanoparticles were synthesised through a one-step hydrothermal reaction. A resistive-switching memory device with Ag/CaWO4/fluorine-doped tin oxide structure was prepared. This device presents photo-induced multiple-state memory behaviour at room temperature. This study is valuable for exploring multi-functional materials and their applications in photo-controlled multiple-state non-volatile memories.

With extremely high critical current density (Jc) and excellent strain tolerance, Nb3Al superconductor is considered as an alternative to Nb3Sn for application of high-field magnets. However, owing to their complex structure, Nb3Al superconducting wires can hardly meet the requirement of engineering application at present. In this work, we have reported the manufacture of a single core-structured jelly-roll Nb3Al precursor long wire. While using homemade rapid heating and quenching (RHQ) equipment, we have successfully carried out RHQ heat-treatment of Nb3Al wire samples with various heating conditions, especially the effect of the Joule heating currents by rapid heating, quenching and transformation (RHQT) method on the phase formation and the superconducting properties of the wires were investigated.

In this work, the Cu(In1-xGax)Se2 (CIGS), Al doped ZnO (AZO) and Mo has been used for constructing a resistive switching device with AZO/CIGS/Mo sandwich structure grown on a transparent glass substrate. The device represents a high-performance memory characteristics under ambient temperature. In particularly, a resistance ratio change phenomenon have been observed in our device for the first time.

Advanced rechargeable Na-ion battery is favored by researchers owing to its relatively low-priced and earth-abundant resource. In this work, BiFeO3 nanoflakes by compositing with organic pectin as an outstanding anode material for rechargeable Na-ion batteries were fabricated by an improved hydrothermal process for the first time. We found that the BiFeO3/pectin nanoflakes as anode hold long life and excellent charge–discharge performance with reversible capacity of 450 mAh g–1, which can retain 100% capacity after 100 charge–discharge cycles. It is inferred that the excellent performance of Na-ion batteries is contributed to viscoelastic pectin among BiFeO3 crystal lattices. The organic pectin can play a buffer role in the process of BiFeO3 crystal lattices expansion when Na ions inserted, indicating the BiFeO3/pectin nanoflakes are not easily degenerated as anode in Na-ion battery. This work provides great potential for fabricating low-priced and high power density Na-ion batteries for electronic equipm...

To study the fire resistance of different types of composite beams in integral structures, transient state tests were performed on two-span composite beams (one span is a monolithic composite beam with a laminated slab and the other span is a composite beam with a cast-in-place slab) with rigid beam-to-column connections. The temperature distribution, displacement changes, and failure modes of the two types of composite beams were evaluated in tests mimicking the entire process of a real fire disaster. The following results were obtained in this study. Under the influence of fire, cracks of different patterns were formed on different types of composite beams. When the heating was stopped, the temperature of the steel beam experienced a sudden and sharp drop, whereas the temperature of the concrete slab rose within a short period of time. These behaviours cause the composite beam to undergo retraction in a reverse arch shape during deformation. Severe buckling occurred in the lower flange under the two ends of the steel beam as well as the web of the steel beam. During the test, the welds at both ends of the laminated-slab composite beam were cracked, whereas those at both ends of the composite beam with a cast-in-place slab remained undamaged. Finally, a method for calculating the axial force of the composite beam that considers the constraints at the beam ends is proposed in this study. The calculation results are in good agreement with the experimental test results.

In this work, the resistive switching mechanism of metal/MoS 2 /Ti/Si devices with different metal acts top electrode materials have been investigated. The device represents an outstanding memory behavior with larger storage window when using Ag acts top electrode. This work reveals that Ag filaments can be easily formed by redox process in MoS 2 film.

High-polluting industrial ammonia synthesis runs counter to the intentions of a low-carbon society. In contrast, the electrocatalytic nitrogen reduction reaction (NRR) is expected to provide fascinating and broad prospects for green ammonia synthesis, which urgently requires efficient and low-cost catalysts. Although it has been proven that two-dimensional (2D) transition metal carbides and carbonitrides (MXenes) have great potential for NRR, there is still need to further improve their activity. In this work, a co-doping strategy was employed to design the electronic configuration and structural mechanic of Ti3C2Tx catalysts for efficient NRR. As expected, the synergistic effect of N and S dopants in Ti3C2Tx (NS-Ti3C2Tx) significantly improves the electron/ion transport capacity and increases the catalytic active sites. Specifically, the as-prepared NS-Ti3C2Tx nanosheets demonstrated an excellent electrocatalytic stability with NH3 yield of 34.23 μg h−1 mg−1cat at −0.55 V vs. RHE, and a Faraday efficiency of 6.6% in 0.05 M H2SO4. Therefore, this work opens up a new research approach for preparing high-performance catalysts for energy storage applications through efficient nitrogen fixation technology.

In this work, hexagonal MoSe2 nanosheets were prepared by hydrothermal process. Next, the resistive switching memory behaviour of single MoSe2 nanosheets was further investigated. We observed that MoSe2 nanosheets based memory device show reproducible and stable bipolar resistive switching memory characteristics. Through the analysis for conductive mechanism, the formation and rupture of nanoscale Ag filament inside the MoSe2 nanosheets is suggested to explain the memory behaviour.

In this work, the MoSe 2 nanosheets were firstly prepared by hydrothermal method. We found the magnetism of MoSe 2 nanosheets obviously enhance with the decrease of temperature. Further, we fabricated a memristor using as-prepared MoSe 2 nanosheets, and observed temperature can regulate the memristor memory behavior of the device. In a word, this work reveals the potential multifunctional applications of MoSe 2 nanosheets with magnetism and memristive memory effects in future device technology.

A simple sol-gel method with butterfly as a biotemplate to prepare Li 4 Ti 5 O 12 -TiO 2 (LTO-TiO 2 ) nanostructures is presented in this study. Results show that the LTO-TiO 2 has a periodical 3-dimension (3D) nanostructure, and delivers a high reversible capacity of 169 mAh/g and nearly 100% capacity retention over 80 charge-discharge cycles. Furthermore, LTO-TiO 2 nanostructures exhibit an excellent rate capability of 56 mAh/g at 20 C. It is believed that the high performance of the anode materials can be attributed to the high surface area and perfect electron transport channels of 3D periodical nanostructures. We firmly believe that this work hold great promise for providing a perfect reference for artificially synthesized micro-nanostructure materials.

Composite particles (CPs) with an average diameter of 100 gm, containing the amorphous silicates, but crystal structures are dominated by the NaS2, Al2S3, Al0.55Mo2S4 and MoO3, are synthesized using hydrothermal method. Bipolar resistive switching (RS) memory behaviors with favorable resistance ON/OFF ratio, high retention and voltage cycling endurance performance are observed in the CPs-based device. The RS memory behaviors can be well controlled by stressing visible light at room temperature. The traps/deep traps based physical modes are proposed to interpret the RS memory behaviors for the quasi-bulk silicate-based composites. Different from conventional nano-scale RS memory device, the discovery of the RS memory behavior of micro-scale silicate composites may provide one new insight into the mechanism of resistive switching behavior. (C) 2017 Published by Elsevier Ltd.