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The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction (HER) catalyst for renewable energy applications. Metal hydroxide such as Ni(OH)2 has been proven useful for promoting alkaline HER, but the performance remains unsatisfactory. Herein, the electronic structure of Ni(OH)2 is modulated by the interfacial electron rearrangement between Ni-Ni(OH)2 heterojunction. Combined experiments with DFT simulations, the electrons of Ni species accumulate to the interfacial Ni-Ni(OH)2 sites, which modifies the d band center for promoting conversion of hydrogen intermediates and narrows the energy gap for boosting charge transfer in the HER process. Thus, the integrated electrode exhibits an efficient HER performance to drive 10 mA cm−2 at the overpotential of 72 mV with a low Tafel slope of 43 mV dec−1. Our work renders a valuable insight for understanding and rationally designing efficient catalysts in alkaline HER.

The isothermal equilibrium method was used to study the stable phase equilibria of the quinary system Li+, K+, Mg2+//Cl‒, $${{{\text{B}}}_{{\text{4}}}}{\text{O}}_{7}^{{2 - }}$$ –H2O at 273 K. The solubility data of each component in this system were measured through experiments, and the isothermal phase diagram of this system was also drawn. For the identification of the equilibrium solid phases of the invariant points, X-ray diffraction characterization was used. The projection surface of the stable phase diagram of the quinary system Li+, K+, Mg2+//Cl‒, $${{{\text{B}}}_{{\text{4}}}}{\text{O}}_{7}^{{2 - }}$$ ‒H2O at 273 K was drawn under the saturation condition of MgB4O7. The simplified dry-salt diagram has carnallite (KCl·MgCl2·6H2O) and lithium carnallite (LiCl·MgCl2·7H2O), and it contains eleven univariate solubility curves, five invariant points and seven crystallization regions corresponding to K2B4O7·4H2O, Li2B4O7·3H2O, KCl, MgCl2·6H2O, and LiCl·2H2O and double salts carnallite (KCl·MgCl2·6H2O) and lithium carnallite (LiCl·MgCl2·7H2O). In the quinary system, by comparing the area of each crystalline phase zone, lithium chloride is a highly soluble salt, therefore, in the solubility diagram, in comparison with magnesium tetraborate, it corresponds to the smallest crystallization area.

Thin-film architectures are a staple in a wide range of technologies, such as semiconductor devices, optical coatings, magnetic recording, solar cells and batteries. Despite the industrial success of thin-film technology, mostly due to the easy fabrication and low cost, a fundamental drawback remains: it is challenging to alter the features of the film once fabricated. Here we report a methodology to modify the thickness and sequence of the innermost solid-state thin-film layers. We start with a thin-film stack of amorphous iron oxide and silver. By applying a suitable voltage bias and then reversing it, we can float the silver layer above or below the oxide layer by virtue of the migration of silver atoms. Scanning transmission electron microscopy reveals various sequences and thicknesses of the silver and oxide layers achieved with different experimental conditions. As a proof-of-principle, we show a dynamic change of structural colours of the stack derived from this process. Our results may offer opportunities to dynamically reconfigure thin-film-based functional nanodevices in situ.

Memristive devices based on two-dimensional (2D) semiconducting materials have emerged as highly promising neuromorphic devices due to their intrinsic atomic body and unique properties. However, th...

Adsorption behavior determines catalytic efficiency in the hydrogen evolution reaction (HER). Thus, engineering catalytic adsorption sites provides an opportunity to investigate in depth the active areas of catalysts. Herein, we put forward an adsorption site engineering strategy to increase the density and intrinsic properties of adsorption sites in Ni(OH)2 by doping with Cu2+. Benefiting from the Jahn–Teller effect of Cu2+, introducing lattice distortion affords Cu–Ni(OH)2 abundant active sites for intermediate conversion. Furthermore, combining experiments with DFT simulations, the doping of Cu2+ in Ni(OH)2 causes local electron accumulation and modulated d electron state, affording Cu–Ni(OH)2 with preferable adsorption behavior for efficient intermediate conversion. As regards the electrochemical results, the obtained Cu–Ni(OH)2 integrated electrode exhibits appealing catalytic activity toward the HER at an overpotential of 53 mV to drive 10 mA cm−2 along with a low Tafel slope of 51 mV dec−1. Hence, we believe that the adsorption site engineering strategy renders a valuable solution for designing efficient catalysts for use in alkaline HER.

Transient electronics is an emerging class of electronics that has attracted a lot of attention because of its potential as an environmental-friendly alternative to the existing end-of-life product disposal or treatments. However, the controlled degradation of transient electronics under environmentally benign conditions remains a challenge. In this work, the tunable degradation of transient electronics including passive resistor devices and active memory devices was realized by photodegradable thin polymer films comprising fullerene derivatives, [6,6]-phenyl-C61-butyric acid methyl esters (PCBM). The photodegradation of polymer:PCBM under an aqueous environment is triggered by ultraviolet (UV) light. Experimental results demonstrate that the addition of PCBM in commodity polymers, including but not limited to polystyrene, results in a catalytic effect on polymer photodegradation when triggered by UV light. The degradation mechanism of transient electronics is ascribed to the photodegradation of polymer:PCBM encapsulation layers caused by the synergistic effect between UV and water exposure. The polymer:PCBM encapsulation system presented herein offers a simple way to achieve the realization of light-triggered device degradation for bioapplication and expands the material options for tailorable degradation of transient electronics.

In this work, the solid-liquid phase equilibrium in the ternary system KCl−KBr−H2O at T = 273 K has been investigated by using the isothermal dissolution equilibrium method. Based on determined solubility data of saturated liquid phase and corresponding humid residue composition, the experimental phase diagram has been constructed. The result shows that the type of the system is classified as completely solid solution type due to the existence of solid solution K(Cl, Br). The phase diagram of the ternary system KCl−KBr−H2O at 273 K is divided into an unsaturated liquid phase filed and one solid crystalline phase region corresponding to K(Cl, Br) by an univariant solubility curve on which there is without any invariant point. The function which described the relationship between the composition of solid solution and the solubility of two salts in saturated liquid phase was constructed by multiple regression. The Pitzer equation has been selected to calculate the solubility data in the ternary system KCl−KBr−H2O at T = 273 K. The solubility modelling approach agrees with experimental solubility data.

A novel bending sensor based on an in-fiber Mach–Zehnder interferometer (MZI) has been fabricated by femtosecond laser. The MZI is formed by an off-axial straight waveguide inscribed in a no-core fiber spliced between two standard single mode fibers. The in-fiber MZI is formed due to the interference of a fundamental mode and a higher-order mode which excited in the no-core fiber. Analysis results of the structure agree well with the measured transmission spectra. Experimental results show that the device has low temperature crosstalk and high curvature sensitivity of 14.91 nm/m−1 and 12.86 nm/m−1 for the 0° and 180° orientations in the range of 0–3 m−1, respectively. We can distinguish the bending orientation of the device by the shift direction of the spectrum. The advantages of high sensitivity, low temperature crosstalk, compact structure, and easy fabrication make the device attractive for actual engineering bend sensing.

Two noncentrosymmetric haloplumbate hybrids, [C6H10(NH3)2][PbCl4] (1) and [C6H10(NH3)2][PbBr4] (2), have been synthesized. Crystals of 1 and 2 belong to the chiral space group P212121. The inorganic parts comprise a one-dimensional chain structure for 1 and a two-dimensional sheet structure for 2. Both compounds exhibit thermochromic luminescence originating from dual emission and have potential applications as self-referencing luminescent thermometers.

To develop earth-abundant and cost-effective catalysts for overall water splitting is still a major challenge. Herein, a unique “raisins-on-bread” Ni–S–P electrocatalyst with NiS and Ni2P nanoparticles embedded in amorphous Ni(OH)2 nanosheets is fabricated on Ni foam by a facile and controllable electrodeposition approach. It only requires an overpotential of 120 mV for HER and 219 mV for OER to reach the current density of 10 mA cm−2 in 1 M KOH solution. Employed as the anode and cathode, it demonstrates extraordinary electrocatalytic overall water splitting activity (cell voltage of only 1.58 V @ 10 mA cm−2) and ultra-stability (160 h @ 10 mA cm−2 or 120 h @50 mA cm−2) in alkaline media. The synergetic electronic interactions, enhanced mass and charge transfers at the heterointerfaces facilitate HER and OER processes. Combined with a silicon PV cell, this Ni–S–P bifunctional catalyst also exhibits highly efficient solar-driven water splitting with a solar-to-hydrogen conversion efficiency of 12.5%.

Vanadium sulfides, such as VS2, have been often used as sulfur host materials for lithium–sulfur batteries (LSBs), however, their high-symmetry and layered crystalline structure often lead to a poor rate-capability and a limited cycling stability of the resultant LSBs. Thus, in this work, a type of distorted NiAs-type structured V2S3 phase was designed and attempted to use it as a sulfur host for LSBs. The results showed that the prepared V2S3-nanocrystal decorated carbon nanofiber (CNF@V2S3) electrode films are freestanding, highly conductive and flexible. And the resultant CNF@V2S3/S cathodes show a high specific capacity (1169 mA h g−1 at 0.1C), an excellent rate capability (retain 78.9% at 2.0C), an ultra-low delay rate per cycle of 0.0071%, and a low self-discharge rate of 3.65% per month. A series of analyses indicate that these high electrochemical performances are mainly due to the high polarity, high conductivity and high catalytic activity of V2S3 nanocrystals, as well as the improved diffusivities of Li ions. This research could provide some new insight into the design of sulfur host materials for high-performance LSBs.

By semi-analytical modifications to Mackenzie’s equation, a new third-order relation between bulk modulus and porosity is developed for porous materials. Compared with Mackenzie’s equation, the proposed equation takes into consideration critical porosity and real geometry represented by the assembly of hollow spheres. It has been shown that the proposed equation is in better agreement with 10 sets of published data than Mackenzie’s equation and that has an advantage in predicting the matrix bulk modulus even lack of the data of dense porous specimens. In addition, the proposed equation can describe the bulk modulus of porous materials with critical porosity well. However, Mackenzie’s equation cannot work.

Neuromorphic computing has emerged as a highly promising alternative to conventional computing. The key to constructing a large-scale neural network in hardware for neuromorphic computing is to develop artificial neurons with leaky integrate-and-fire behavior and artificial synapses with synaptic plasticity using nanodevices. So far, these two basic computing elements have been built in separate devices using different materials and technologies, which poses a significant challenge to system design and manufacturing. In this work, we designed a resistive device embedded with an innovative nano-vacuum gap between a bottom electrode and a mixed-ionic-electronic-conductor (MIEC) layer. Through redox reaction on the MIEC surface, metallic filaments dynamically grew within the nano-vacuum gap. The nano-vacuum gap provided an additional control factor for controlling the evolution dynamics of metallic filaments by tuning the electron tunneling efficiency, in analogy to a pseudo-three-terminal device, resulting in tunable switching behavior in various forms from volatile to nonvolatile switching in a single device. Our device demonstrated cross-functions, in particular, tunable neuronal firing and synaptic plasticity on demand, providing seamless integration for building large-scale artificial neural networks for neuromorphic computing.

We have developed a lithography free technique for the fabrication of two-dimensional material based devices for electrical characterization. We fabricated few-layer and multilayer WS2 devices using a transmission electron microscope (TEM) grid as a shadow mask, and its transport characteristics were studied by electrical measurements. WS2 samples were synthesized by first depositing WO3 followed by sulfurization and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. Each sample was exposed to hydrazine at varying pressures, and their electrical resistances were monitored during adsorption (exposing to hydrazine vapor) and subsequent desorption (by pumping). The WS2 sample consisting of two layers showed a decrease of resistance upon exposure to hydrazine vapor and showed complete reversibility upon pumping. The WS2 sample with three layers showed a decrease of resistance during exposure but showed only partial recovery during desorption. In contras...

Twins in micas are difficultly identified due to mica’s hexagonal pseudosymmetry. Many theoretic studies on mica twins have been reported but experimental observations are very limited. In this paper, we present an electron backscattered diffraction analysis to identify twins in the muscovite in a quartz schist occurring in the UHP-HP metamorphic rock belt in Dabie Mountain, China. A trilling twin with twin law /{110} is common in the muscovite. A six-couplet twin consisting of two trilling twins related by twin laws /{130} and /{001}(or /{100}) has been discovered. This six-couplet twin contains many cross-twin relationships among the most common mica twin laws /{110}, /{130} and /{001}. The composition plane for twin laws /{130} and /{001} is {001} which is reasonable in mica structure to form a twin by rotation around twin axes, and that for twin law /{110} is irregular based on EBSD resolution. A possible misindexation of a trilling twin or a 3T polytype during EBSD test is discussed, which is helpful to distinguish a twin from a polytype in micas. The occurring frequency of twin law /{110} is higher than that of twin laws /{130} and /{001}, which is consistent to the deducing result from mica structure analysis. This research provides a convenient and effective EBSD method to identify mica twins and an experimental method to distinguish a twin from a polytype in micas, which is a problem confusing researchers for many years.

A three-dimensional (3D) graphene interconnected network coupled with uniformly dispersed α-Fe2O3 nanorings (α-Fe2O3@GA) was designed by a simple hydrothermal self-assembly strategy and was used as anode material for lithium-ion batteries (LIBs). The α-Fe2O3@GA composites delivered a reversible capacity of 1288 mA h g−1 over 100 cycles at 100 mA g−1 and excellent rate performance than those of pure α-Fe2O3, owing to the synergetic effect of hollow α-Fe2O3 nanorings and inherent 3D porous graphene aerogels. In virtue of their superior lithium storage performance, the α-Fe2O3@GA composites will be promising lithium-ion battery anode materials. Moreover, this study provides a versatile route to synthesis other 3D graphene aerogel-based transitional metal oxide materials for commercial applications in lithium-ion batteries.

Atomic switches are promising candidates as the basic building blocks for large-scale neuromorphic networks due to their tunable switching behaviors. Several neuromorphic components based on atomic switches have been demonstrated, including artificial synapses, artificial neurons and short-term to long-term memory, making it possible to construct neuromorphic systems using a unified device. Although the mechanism of atomic switches has been actively studied, most of the discussions in previous studies are qualitative and failed to provide a comprehensive view of the dynamics that can precisely describe the metallic bridging under an electric field. In this paper, we designed a gap-type atomic switch and realized various switching behaviors, including both volatile and non-volatile resistive switching. Employing advanced microanalysis technology, we experimentally studied the switching mechanism and captured the nanoscale metallic filament in gap-type atomic switches. Furthermore, based on the experimental findings as well as on the electrochemistry fundamental and electron tunneling effect, we proposed a physical model that precisely reproduced the sophisticated switching behaviors. Our model mathematically described the growth/shrinkage dynamics of nanoscale metallic filaments, providing a direction for studying the switching behaviors from a quantitative view. The simulation results are in good agreement with the experimental findings in both DC sweep and pulse operation modes. In addition, we have demonstrated neuronal tonic spiking and short-term to long-term memory in experiment and simulation, indicating that our model can be applied to the circuit level simulation of large-scale atomic switch arrays for neuromorphic applications.

MXenes have attracted wide attention in the field of energy storage due to their high electrical conductivity, good hydrophilicity and diversified surface terminals. Herein, Ti2C MXene film with good flexibility was successfully prepared which exhibits excellent gravimetric capacity in the currently reported MXene family. And the coupling mechanism of the surface terminations of Ti2C MXene in aqueous electrolytes on the capacitance behavior were proposed. The flexible Ti2C film directly used as electrode for supercapacitors shows good electrochemical performance with specific capacitance up to 382 F g-1 at 2 mV s-1 and 265 F g-1 at 100 mV s-1, indicating that it is a promising electrode material for supercapacitors.

The growing demand of infrared sensors for emerging applications such as autonomous vehicles and remote control and sensing systems has driven the development of flexible, low-power, and sensitive infrared detectors for seamless product integration. Although semiconducting polymer (SCP)-based photodetectors are promising solutions, challenges in synthesis chemistry and high thermal dark currents associated with narrowing of band gaps have limited their progress. To address these challenges, we have designed a new class of composites comprising SCPs with moderate band gap and rare earth doped-nanoparticles (RENPs) that enable photon-to-electron conversion beyond the SCP's response range. Using this RENP-SCP (RE-SCP) composite, we demonstrated detection at multiple wavelengths (808, 975, and 1532 nm) for planar-type photodetectors. Notably, the RE-SCP composite-based device detected an eye-safe, shortwave infrared (SWIR) source at 1532 nm with high SWIR responsivity of 0.02 A/W and an SWIR external quantum efficiency of 2%. The key attribute governing the excellent SWIR responsivity and sensitivity was the distinctive SWIR upconversion characteristic of RENPs that extended and improved the SCP's detection range and performance, respectively. Additionally, the absence of significant performance degradation of the SWIR photodetector for bending curvatures from 0-0.67 cm

An investigation was performed into the rheological behavior of highly concentrated water-in-oil emulsion (HCE). The experimental results show that HCE behaves as a shear-thinning fluid and there are two platforms in the flow curve. But, the second platform at high shear rate region can't be observed with the increase of the intensity of interaction between droplets caused by the decrease of the size of dispersed phase droplets. The recovery capacity of HCE underwent shear was affected by the size of dispersed phase droplets. Relatively strong resilience was observed when the droplet size of dispersed phase was small. However, the recovery capacity of HCE underwent oscillation was not affected by the droplet size. The nature of surfactant, oil and the AN content of dispersed phase have important effect on the rheology of HCE. The plateau zone of storage modulus goes to a higher level when the blended surfactant used as surfactant. There is optimal oil viscosity region within which the higher G' can be formed. The G′ of HCE decreases obviously, while the oil-water interfacial tension decreases. The G′ decreases with the increase of the concentration of ammonium nitrate.

A frequency-selective, tunable terahertz (THz) filter based on a flexible tape is designed and characterized for a low-cost and easy-access THz filter with a wide range of center wavelengths (CWL) from 150 to 600 μm (2.0 to 0.5 THz). With more than 85% bandpass transmission and 10 dB bandstop reflection at the CWLs, the proposed filter based on metallic crossed-slot hole arrays are fabricated on a 50-μm polyimide film with low absorption and good mechanical properties, resulting in a large-area, free-standing, and flexible membrane with a low intrinsic loss. The frequency dependent characteristics of the filter are investigated by THz time-domain spectroscopy and excellent agreements between the measured and simulated results are demonstrated. The designed THz filter possesses not only a simple structure and polarization insensitivity, but also a light weight and high integration.

Physically transient electronics, which can disappear under certain conditions in aqueous solutions or biofluids, has attracted increasing attention because of its potential applications as "green" electronics and biomedical devices. Till now, the excitation of the transient process is achieved by passive dissolution of the encapsulation layer, which has a very limited control over the process. Here, we report a novel light-triggered encapsulation strategy via a bilayer of a light-responsive hydrogel and oxide to control the degradation on demand in aqueous environment. The hydrogel serving as a barrier between the environment and oxide limited the water's movement and penetration, leading to improved stable operation time. More importantly, the light-responsive hydrogel underwent a gel-to-solution transition upon applying ultraviolet (UV) light. The drastic change of the water movement enabled a transient process triggered on demand. Via this encapsulation scheme, we demonstrated fully soluble resistors and resistive random access memory devices with the UV light-triggered transient process. This work provides a new pathway to design transient devices with controllable degradation to meet various requirements of green electronics and biomedical devices.

The widespread implementation and rapid development of autonomous systems pose stringent performance requirements on emerging sensory systems. In addition to the basic sensing requirements, leading sensory systems are required to process data and extract featured information from highly redundant data in real time. With the added edge‐computational capabilities, data shuttling is avoided, leading to significant reduction of computational burden and bandwidth pressure in the cloud. Among the different computing architectures, the neuromorphic sensory system stands out due to its high power efficiency, low latency, and excellent processing capability. Mimicking the biological neural network, the colocation of sensory, processor, and memory components of neuromorphic sensory systems enables the requirements for frequent data shuttles to be circumvented. In particular, artificial intelligent perceptions built on memristive neuromorphic systems exhibit outstanding characteristics of small footprint, low power consumption, 3D stacking ability, and high density. Herein, the two essential parts of the memristive artificial perceptron system are presented: 1) memristive systems for neuromorphic computing and 2) high‐performance sensors. Next, the current state of the art established on artificial perceptron systems covering visual, auditory, and tactile sensations is highlighted. To conclude, the current challenges and future direction in the area of advanced intelligent perceptions are presented.

Herein we report the first example of the proton conductivity of an open-framework metal phosphate (NH3(CH2)3NH3)2–[Fe4(OH)3(HPO4)2(PO4)3]·4H2O under aqua-ammonia vapor. Its optimized proton conductivity is 5 × 10−2 S cm−1 at 313 K and aqua-ammonium vapor from 1 M NH3·H2O solution. That is approximately two orders of magnitude greater than the maximum value under water vapor (8.0 × 10−4 S cm−1 at 317 K and 99% RH). The proton transfer mechanism has been proposed in terms of the structural analyses, activation energy calculations, and PXRD determinations.

An eccentric small-period long-period fiber grating sensor with a period of 36μm fabricated by femtosecond laser is reported. The sensor exhibits high sensitivity for curvature and external refractive index and low temperature cross sensitivity.

In conventional deep drawing lubricants are applied to achieve low friction and wear. However, most lubricants contain environmental harmful ingredients. Global trends like sustainability and efficient resource usage motivate the development of lubricant-free deep drawing. However, dry contact conditions lead to intensive interaction between tool and workpiece especially for aluminum alloys with high adhesion tendency towards tool steel. First investigations revealed promising results for diamond like carbon (DLC) coated tools in lubricant-free tests. Therefore, in this study the lubricant-free friction and wear behavior of DLC coatings is investigated in strip drawing tests. To ensure industrial-like conditions commonly used deep drawing steel with zinc coating and an aluminum alloy were selected as sheet material. The properties of DLC coatings were modified at different scales to attain tailored tribological conditions. A laser based heat treatment achieved an increase of sp2 hybridization and thus leads to increased friction. Different mechanical pre- and post-treatment strategies like polishing and brushing proved that a smooth tool surface is beneficial for the tribological conditions in dry contacts. With laser generated structures a modification of friction was realized with varying degree of coverage for DC04. In contact with AA5182 the application of structures is limited due to adhesion.

Urea is a small molecule produced in millions of tons per day and is ubiquitous in nature. Biological treatment is commonly used to oxidize the urea wastewater produced each day across the world, which produces additional solid waste and eliminates any potential for utilizing the stored chemical energy within. A solar waste-to-fuels concept is presented to synergistically produce hydrogen fuel from visible sunlight while remediating urea wastewaters. A cascade semiconductor-catalyst electrode assembly was designed to drive the photoconversion of urea to hydrogen. Proper band energy alignment facilitates catalyst activation via hole transfer across the semiconductor–catalyst interface. Specifically CdS-sensitized TiO2 with Ni(OH)2 urea electrocatalyst on fluorine-doped tin oxide coated glass was employed as photoanode. The steady-state response of the semiconductor–catalyst electrode is investigated in a photoelectrochemical cell, and charge transfer and recombination kinetics are elucidated to identify li...

Lubricant-free sheet metal forming increases resource efficiency and contributes to environmental protection. However, the direct contact between work tool and workpiece leads to increasing friction and wear. One approach to reducing friction and wear in dry forming is the tool-sided application of carbon-based coatings. In this work, amorphous hydrogenated carbon (a-C:H) coatings were prepared by plasma-enhanced chemical vapour deposition (PECVD). The coating samples were deposited under different amounts and ratios of acetylene and argon gas atmospheres. The coating samples were characterised regarding their thickness and mechanical as well as chemical bond structures. The tribological behaviour against aluminium alloys was investigated under lubricant-free conditions with a ring-on-disc tribometer. Finally, one a-C:H coating variant with promising tribological performance against aluminium alloys was exemplarily tested in a flat strip drawing test, which models the tribological conditions in the flange area of a deep drawing process. With help of the test results, the friction and wear mechanisms during dry sliding in both closed and open tribological systems were discussed.

An investigation was performed into the performance of emulsion explosive via studying on the storage modulus of its matrix. The experimental results show that there is a tight relationship between storage modulus and the performance of emulsion explosive because both have strong connection with droplet size. A higher G′ represents a superior performance of emulsion explosive. The storage modulus was taken to investigate the effect of the nature of surfactant and continuous phase on the performance of emulsion explosive. It was found that the stronger interaction between surfactant and dispersed phase improve the performance of emulsion explosive. But, the increase of polarity of continuous phase decreased the performance of emulsion explosive.

A 1D open framework inorganic-organic hybrid metal phosphate, compound (C4H12N2)1.5[Fe2(OH)(H2PO4)(HPO4)2(PO4)].0.5(H2O) was synthesized via solvothermal method. The inorganic anion layer is built from FeO6 cluster units, and the interlayer spaces are filled by the charge-compensated piperazinium cations. The resultant compound had high storage, aqua and thermal stability by placing its samples in the air for one year, immersing in water for 7 days and performing in the temperature range of 298–1073 K with TG analysis, respectively. This compound exhibited significant temperature and humidity dependence proton conductivity, achieving 5.14 × 10-4 S.cm−1 at 313 K and 99% RH. Moreover, its composite membranes with PVDF also possessed good and sustaining proton conduction behavior (3.78 × 10-4 S.cm−1 at 323 K and 99 %RH), closing to that of its powder although the PVDF isn’t electric conductive.

As a precursor of H2O2, MgO2 attracts great attention in antibacterial applications. Ultrasmall MgO2 nanoparticles possess large surface area and high reactivity, presenting a potential to further improve the antibacterial efficiency. However, the synthesis of uniform ultrasmall MgO2 nanoparticles is still a great challenge. Here, MgO2 nanoparticles with an average diameter of 5 nm have been facily synthesized. The ultrasmall nanoparticles demonstrate superior bacteriostatic efficacy against E. coli and S. aureus due to the ablity to burst release reactive oxygen species.

An investigation was performed into the flow of highly concentrated water-in-oil emulsions. The viscosity of the low shear rate region in the downward curve was much higher than the viscosity of th...

An investigation was performed into the structure recovery of highly concentrated water-in-oil emulsions (HCEs) under shear flow via studying their rheopexy. Experiments with the shear rate sweep in the up and down modes demonstrate that HCE has rheopexy. Restoration of the initial structure after cessation of shearing needs a period of time. The recovery time and ratio depend on the shear rate and the droplet size of the dispersed phase. A high shear rate results in a high probability of structure break of HCE. Thus, it is difficult to return to its initial structure. The structure of HCE that underwent shearing is closer to its original situation when the droplet size is small.

Tin disulfide (SnS2), one transition metal dichalcogenide (TMD) is a cost-effective and promising electrocatalyst for hydrogen evolution reactions (HER) in the alkaline electrolytes. Its electrocatalytic HER performance is unfortunately limited, originating from its un-conspicuous inherent catalytic activities and non-favorable adsorption sites for hydrogen. Herein, a tin disulfide/stannic oxide (SnS2/SnO2) heterostructure is designed and grown on the nickel foam (denoted as SnS2/SnO2-NF). The SnS2/SnO2 heterostructure introduces more active (100) facets or a high density of active sites, accelerates the diffusion kinetic of electrons and ions, lowers the water dissociation energies, and optimizes adsorption energies of hydrogen atoms. On this catalyst, superior HER performance is realized in an alkaline medium. An overpotential of 108 mV at a current density of −10 mA cm–2 with a Tafel slope of 50.1 mV dec–1 and long-term durability are achieved for HER in 1 M KOH. This work paves a new way to design high-performance HER electrocatalyst through facet engineering of the designed heterostructures.

Developing highly active and stable electrocatalysts for acidic oxygen evolution reaction is still a great challenge. Herein, we developed a novel self-supported amorphous IrOx catalyst (IrOx/Ti) encapsulated with a small number of crystalline nanoparticles for efficient acidic OER. The resulting IrOx-50-AC/Ti electrode exhibits a superior OER performance with an overpotential of 250 mV at 10 mA cm−2 and Tafel slope of 50.4 mV dec−1 in 0.1 M HClO4. High contents of IrIII species and surface hydroxide groups, hierarchically porous structure and high defective density contribute to boost the OER activity. Importantly, the amorphous IrOx-50-AC/Ti also demonstrates a super long-term durability for 190 h due to the strong interaction between IrOx film and Ti. The unique amorphous-crystalline structure also enhances the stability and the activity by promoting the synergy between amorphous phase and crystalline phase. This work provides some valuable insights on developing efficient Ir-based catalysts for acidic water splitting.

In this paper, an ultra high molecular weight polyethylene (UHMWPE) lithium ion battery composite separator was successfully prepared via the electrospraying technique. First, the optimal electrospraying parameters of Polyvinylidene fluoride (PVDF), mass fraction of PVDF 3wt% and electrospraying voltage 21kV, were successfully determined by adjusting the effect of voltage and concentration of PVDF solution. Then the composite separator was prepared by electrospraying PVDF particles on the UHMWPE film. Finally the porosity rate, thermal stability and charge and discharge properties of the separator were analyzed. The analytical results show that the porosity rate of the composite separator is increased from 46.5% to 73.1%, and the heat shrinkage of the separator in the longitudinal is reduced from 2.6% to 1.3%. The first specific discharge capacity of the composite separator increases by 5.8%, and the separator has a good cycle stability after 50 cycles.

This review explores the rheology of emulsion explosive, especially the emulsion explosive matrix, through summarizing its flow, yield stress, viscoelasticity and effect on the assessment of stability and performance of emulsion explosive. The emulsion explosive matrix is defined as highly concentrated emulsion due to the volume fraction of dispersed phase exceed 74%. There are two important characteristics of microstructure for emulsion explosive matrix should be considered, that is the polydispersity and deformation of compassed dispersed droplets. This microstructure feature confers matrix good elasticity and solid-like rheological behavior. But, the rheological behavior of matrix will vary from elastic to sticky flow under strong shear stress, in which the deformed droplets will also undergo further deformation and even flow. Obviously, whether the droplet can return to its initial state after deformation or flow is very important for the stability and performance of explosive because the emulsion explosive must be experiencing a certain length of flow in the pipeline before blasting, and this ability is strongly attributed to the droplet size of matrix. Besides that, the main rheological properties of matrix, such as: yield stress, storage modulus, zero shear viscosity and so on, are highly dependent on the nature of emulsifiers and oil materials. The rheology of matrix is changed with the destroy of its microstructure in aging through experimental researches, thus some rheological parameters are considered to be used to assess the stability of matrix. These results will facilitate the further development of methods for predicting the performance and stability of emulsion explosive, as well as the exploration of rheological properties of other types of emulsion explosives, like packaged emulsion explosive and powdery emulsion explosive.

The interfacial issue of nanomaterials-filled epoxy coating has seriously restrained its ongoing progress in actual application. In this paper, we reported a novel design for the robust anti-corrosion and anti-friction performance epoxy coating system based on the self-synthesized 2D Co2(OH)2BDC nanosheets with the native compatible interface compatibility and non-conductivity. The composite epoxy coatings(EP) were intensively characterized by a series of spectral instruments. The influence of the filling content of 2D Co2(OH)2BDC nanosheets to the interface structure of epoxy coating was probed by the microcosmic change. Lastly, the anti-corrosive, mechanical and tribological behaviors of the composite epoxy coatings were extensively investigated. At the optimal filling content of 0.6 wt.%, the low frequency impedance modulus of the 2D Co2(OH)2BDC/EP was increased by about 2 orders of magnitude relative to the neat epoxy coating. Moreover, the friction coefficient of the 2D Co2(OH)2BDC/EP was decreases by 20 % due to the layered structure of nanosheets derived from the weak van der Waals force, while the hardness and Young's modulus were separately increased by 41 % and 83.3 % as a result of the better compatibility and dispersion in epoxy matrix to a certain degree.

New relations are presented to better evaluate the longitudinal and transverse velocities in porous materials under the dry state, respectively. The models are based on semi analytically derived bulk and shear moduli-porosity correlations for dry porous materials. The accuracy and robustness are validated by fitting the published elastic waves-porosity data of different porous materials and a further sensitivity analysis, respectively. The accuracy of the proposed models is averagely higher than that of the empirical Phani’s equation and theoretical Ramakrishnan’s equation. There is an advantage over the Ramakrishnan’s equation to predict the zero-porosity velocity from the data lack of dense porous specimens. The proposed models have a good predictive performance for porous materials with critical porosity and can provide the value of critical porosity, but attention also should be paid to increased sensitivity in this case.

Humidity sensors based on nanofibers have been actively explored due to their unique structures comprising grains and grain boundaries. However, most of the resistance-type sensors lack linearity in sensing response and are operated at high voltages. In this report, resistance-type humidity nanosensors were fabricated from electrospun perovskite KNbO 3 nanofibers and the effects of annealing temperature of nanofibers was investigated. A modified TGA setup was employed to test the absorption/desorption behaviour of the as-annealed nanofibers. KNbO 3 nanofibers annealed at 550 °C displayed the highest sensitivity up to 10 4 for the humidity change from 15% to 90% RH. The I-V curves with respect to relative humidity (RH) measured at different biasing conditions revealed that disassociation of water molecules was dependent on the applied bias voltage thereby affecting the sensitivity. At higher RH environments, biasing the humidity nanosensor at higher voltage improved the linearity in the sensing response. Furthermore, the conductivity values of the as-fabricated humidity nanosensor were reproducible regardless of humidification and dehumidification process. The test outcomes from this study could offer better understanding on the design of high performance humidity sensors based on nanofibers.