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Based on the traditional two-layer accumulative roll bonding (TARB), the geometrical variations and mathematical relationship during the four-layer accumulative roll bonding (FARB) were derived and summarized. Furthermore, the multi-layer accumulative roll bonding (MARB) technology was proposed and the geometrical variations and mathematical relationship of MARB were simultaneously derived and summarized. Experimentally, Mg-14Li-3Al-2Gd (LAGd1432) sheets were fabricated by TARB and FARB, respectively. Compared with the TARB, the FARB has a higher accumulative efficiency in terms of accumulative layers, total number of interfaces, interface spacing, total deformation and equivalent strain. Therefore, the FARB-processed sheets in lower cycles have the similar microstructure and mechanical properties of the TARB-processed sheets in higher cycles. In addition, FARB process can further break through the deformation limit of TARB process in a single cycle through adopting two-step rolling in one cycle with 50% deformation in one pass and 75% accumulative deformation in one cycle, which can effectively solve the problem of poor interface bonding of the latest interface brought by the last cycle, and thus significantly improve the phenomenon of unstable performance of the ARB-processed sheets.

Due to the unique structure of perovskite materials, their capacitance can be improved by introducing oxygen vacancy. In this paper, the LaMnO3-δ material containing oxygen vacancy was synthesized by molten salt method in KNO3 NaNO3 NaNO2 melt. The La–Mn–O crystal grows gradually in molten salt with the increase of temperature. It was confirmed that LaMnO3-δ with perovskite structure and incomplete oxygen content were synthesized by molten salt method and presented a three-dimensional shape. LaMnO3-δ stores energy by redox reaction and adsorption of OH− in electrolyte simultaneously. In comparison with the stoichiometric LaMnO3 prepared by the sol–gel method, LaMnO3-δ prepared by molten salt method proffered higher capacitance and better performance. The galvanostatic charge–discharge curve showed specific capacitance of 973.5 F/g under current density of 1 A/g in 6 M KOH. The capacitance of LaMnO3-δ was 82.7% under condition of 5 A/g compared with the capacitance at the current of 1A/g, and the specific capacitances of 648.0 and 310.0 F/g were obtained after 2000 and 5000 cycles of galvanostatic charging–discharging, respectively. Molten salt synthesis method is relatively simple and suitable for industrial scale, presenting a promising prospect in the synthesis of perovskite oxide materials.

The effects of combined addition of Y and Ce on the microstructure, mechanical properties and anisotropy of as-rolled Mg-8Li-1Al (LA81) alloy were studied. The combined addition of Y and Ce improves the mechanical properties with a low plasticity loss by solution strengthening, dispersion strengthening, grain refinement strengthening. Mg-8Li-1Al-0.6Y-0.6Ce (LA81-0.6Y-0.6Ce) has better mechanical properties and shows an almost isotropy. It possesses an ultimate tensile strength of 278.7 MPa and an elongation of 15.0%. Compared to LA81 alloy, the ultimate tensile strength increases by about 17.6% with an elongation reduction of only 3.5%, and a good isotropy of ultimate tensile strength and elongation (the value of ravg is near 1).

The electrochemical behavior of lanthanide elements deposited on liquid zinc cathodes was studied using cyclic voltammetry (CV) and open circuit chronopotentiometry (OCP). We observed a “bimodal effect” in the equilibrium deposition potentials of zinc with lanthanides. A mathematic equation is derived to illustrate the relationship between the equilibrium potential of the intermetallic compounds formed by lanthanide elements and zinc and their atomic radius. This equation is not only applicable to lanthanide elements but also hold for other elements such as alkali metal lithium, alkaline earth metal magnesium, calcium and transition metal niobium, which have crucial theoretical significance for the electrolysis of intermetallic compounds, the separation, and extraction of metals.

Mg-5Li-1Al alloy was processed by cross accumulative roll bonding (CARB). The processed Mg-5Li-1Al sheet possesses ultra-fine grains, and its strength increases both in the rolling direction (RD) and transverse direction (TD) with the elongation remaining 16˜18%. The proper CARB processing is helpful to improve the isotropy of mechanical properties of Mg-5Li-1Al sheet. At the same time, the CARB process has a beneficial effect on improving the plasticity of Mg-5Li-1Al sheet. With the change of the direction between the CARB passes, the basal texture of Mg-5Li-1Al sheet is weakened, and the non-basal texture is strengthened. Both prismatic slip and pyramidal slip are initiated. The dominant deformation mechanism changes from twin deformation to slip deformation, and finally shear deformation. The grain refinement mechanism changes from twin dynamic recrystallization to continuous dynamic recrystallization, and finally rotational dynamic recrystallization.

With the depletion of terrestrial uranium deposits, a large amount of uranium(VI) (U(VI)) in seawater has attracted the attention of researchers and energy suppliers. However, the extremely low concentration of U(VI) and the complex environment enhance the difficulty of extracting U(VI) from seawater. In this study, a multi-active polyacrylonitrile (PAN) adsorbent was constructed to extract U(VI) from seawater. Poly(amido)amine (PAMAM) with hyperbranched topology was grown onto the surface of PAN fiber by a multi-step method, forming a swollen layer in water. The highest adsorption capacity of the material reached 555.5 mg/g. Importantly, during a continuous 50-day simulated seawater dynamic adsorption process, the material reached an adsorption equilibrium in 15 days, with the adsorption amount of 1.3 mg/g. The ocean test in the Yellow Sea of China showed that the adsorption capacity of the material was 0.6 mg/g in 34 days in seawater environment. The effect of molecular chain conformation and swelling behavior on adsorption properties were investigated. The study on the adsorption mechanism of the material shows that the lone pair of electrons of the N atom coordinates with U(VI).

A pyrochemical conversion of U 3 O 8 into metallic uranium by chemical and electrochemical reactions have been studied. Triuranium octaoxide was chlorinated by carbon tetrachloride gas in a stream of argon at different temperatures. The optimal conditions of the solid phase transformation were found, the conversion rate of U 3 O 8 is up to 99.30%. The mechanism of U 4+ ions reduction into metal uranium by the transient electrochemical technique in the fused 3LiCl-2KCl eutectic was studied. The results revealed that the U 4+ ions reduction to metallic uranium on inert electrode is a two-step reaction, which includes single electron exchange and three electrons exchange. The first step of reaction is reversible and it is controlled by the rate of the mass transfer in the scanning region 0.002–0.2 V/s, while the second step of reaction is irreversible. The diffusion coefficients of U 4+ and U 3+ ions were determined by the cyclic voltammetry. The galvanostatic electrolysis of the LiCl-KCl-UCl 4 melt led to the formation of metallic uranium on an inert solid plate and the formation of intermetallic compounds of different composition on the active liquid gallium cathode. It is concluded that U 4+ ions is easily reduced to metallic uranium in a short period of time during the galvanostatic electrolysis in molten salts.

As a duplex Mg–Li alloy, Mg–9Li–1Zn (LZ91) has attracted increasing attention, but its strength needs to be further improved. This paper aims to explore the effect of Y and Ce in different proportions on microstructures and mechanical properties of LZ91. The microstructures and mechanical properties of as-cast and cold-rolled LZ91 alloys with Y and Ce addition were investigated. The grain size of the LZ91 was refined due to the addition of Y and Ce. Y significantly strengthened LZ91 while Ce weakened the strengthening effect of Y. The mechanical properties increased first and then decreased with the content of Y and Ce, however, it still showed a strengthening effect compared to LZ91 alloys. The addition of Y caused the formation of Mg24Y5 and Mg12ZnY. With the addition of Ce, Mg12Ce and CeZn5 formed with a continuous-network distribution. Mg–9Li–1Zn-1.5Y exhibited the most excellent microstructure and mechanical properties in as-cast state (UTS, YS, and elongation are162MPa, 130 MPa and 49.6%, respectively) and cold-rolled state (UTS, YS, and elongation are 255 MPa, 231 MPa and 31.9%, respectively) states because of the prominent refinement effect of Y on α phase and the dispersion strengthening by Mg24Y5. Meanwhile, the elongation of Mg–9Li–1Zn-1.5Ce after cold rolling was abnormally enhanced. This was explained that the coarse Mg12Ce in the as-cast state was broken into fine dispersed particles after cold rolling. This paper provides a reference for the selection and quantification of rare earth elements in duplex Mg–Li alloys. It also provides a reference way to refine large-size second phases in duplex Mg–Li alloys.

The lack of flexibility of the substrates and the readily shed off of the active materials during the deformation process limit applications of wearable electronic devices. An effective approach is to design an electrode with both high flexibility and stability, which ensure that the device will not be affected in practical applications. In this paper, we design 3D Cu(OH)2 nanowires directly grown on carbon fiber cloth by a quasi-stable electroless Cu deposition and a rapid alkali assistant oxidation process. The Cu-electroless plating ensures high conductivity and excellent binding force between the active material and the substrate, which issued in low internal resistance and remarkable cycle stability. Moreover, the flexible all-solid-state asymmetric supercapacitor (FASSASC) assembled with the Cu(OH)2/CPCC (Cu-plated carbon cloth) as positive pole, possess high areal capacitances (242.5 mF cm−2 at 1 mA cm−2), relatively large energy and power density (4.9 × 10−2 mWh cm−2, 0.6 mW cm−2 respectively), with outstanding cycling stability and flexibility (90.5% capacitance retention after 5000 cycles under bending). Remarkably, we also assembled a self-charging power pack integrated of flexible all-solid-state asymmetric supercapacitors (FASSASCs) and commercial solar cells, which can capture energy from the sun, and then store it to furnish a durative and stable electrical output. Such a device could be powered by the self-charging function without time and location limit. These superior characteristics demonstrate that the Cu(OH)2/CPCC//AC/CC FASSASC a good candidate for next-generation flexible, wearable and portable electronic devices.

Effects of Sc and Zr on microstructure and properties of 1420 aluminum alloy were investigated. With the additions of Sc and Zr, the coarse primary Al3(Sc,Zr) particles formed at the solidification process were difficult to be dissolved into the matrix during homogenization. The precipitations of Al3Li and Al3Li/Al3(Sc,Zr) occurred during aging process. The growth rates of Al3Li and δ′-PFZs were retarded with the additions of Sc and Zr. The mechanical properties were significantly improved with the additions of Sc and Zr. The mechanical properties (UTS = 300 MPa, YS = 211 MPa and EL = 6.8%) were obtained in 1420-Sc-Zr alloy aged at 190 °C for 16 h. Moreover, the thermal diffusivity and corrosion resistance were significantly affected with the additions of Sc and Zr. With the additions of Sc and Zr, the thermal diffusivity was efficiently increased by 28% during aging process, however, the corrosion resistance decreased.

Superhydrophobic coatings have been applied in various fields because of their advantages such as self-cleaning, drag reduction, dustproof, anti-icing, corrosion resistant etc. However, in this study, a new idea imitating the process of growing grass was proposed to solve the low adhesion, weak wear resistance and poor corrosion resistance of the general superhydrophobic coatings: the ratio of epoxy resin to ZnO seeds were strictly controlled so that ZnO seeds are not completely coated. On this basis, a cluster-like ZnO coating composed of interdigitated ZnO rods was prepared. After modification with stearic acid, the coating exhibited superhydrophobic properties with a contact angle of 163° and the coating showed excellent abrasion resistance and noticeable robustness. Due to the barrier from both epoxy resin/ZnO seeds and cluster-like ZnO, the coating performed excellent corrosion resistance. At the same time, the cluster-like ZnO/epoxy resin coating prepared like seeds rooting has good firmness and can be adapted to various harsh environments such as tape peeling, friction between objects, etc., which can expand the application of the superhydrophobic coatings.

A novel adsorbent, metal organic framework (MIL-68) decorated graphene oxide (MIL-68/GO) composites were prepared in this study. The synthesized sorbent was well-characterized by Transmission Electron Microscope (TEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR), which confirmed the MIL-68/GO composites were synthesized successfully. The effects of initial uranium (VI) concentration, temperature, pH and contact time on uranium (VI) sorption behaviour were systematically studied by a series of adsorption experiments. The results showed that the optimal pH was 8. The Langmuir model showed better correlation with the isotherm data, the maximum adsorption capacity was 594.66 mg/g at 298.15 K. The adsorption process fitted well with a pseudo-second-order model. Furthermore, the MIL-68/GO composites also showed good adsorption properties in simulated seawater. At the uranium(VI) concentration 3 µg/L with multi-coexisting metal ions, the distribution coefficient (Kd) value of uranium(VI) was 2.29 × 104 mL/g, which determined that MIL-68/GO composites were a promising material for the enrichment of uranium(VI).

Uranium (VI) is very essential element in nuclear technique and the enrichment uranium has attracted lots of attention. In this work, l -Arginine and Ag nanoparticles (AgNPs) functionalized reduced graphene oxide ternary hydrogel composites (Ag- l -Arg-rGH) were successfully synthesized, which combined the insertion of AgNPs with one-step thermal reduction and an assembly of graphene oxide nanosheets, using l -Arginine ( l -Arg) as both a functional and cross-linking agents. The Ag- l -Arg-rGH composites exhibited great enhanced sorption capacity. Kinetic data best fitted the pseudo-second-order model. The thermodynamic data fitted the Langmuir isotherm model and the calculated maximum adsorption capacity is 434.78 mg/g. In addition, the anti-algae experimental results indicated adsorbent showed marked algal inhibition with the presence of AgNPs in the Ag- l -Arg-rGH composites. In the simulated seawater experiments, The distribution coefficient (Kd) value of uranium(VI) with other competing ions was 2.41 × 104 mL g−1. Thereby, the Ag- l -Arg-rGH composites possessed a promising potential for the enrichment uranium (VI) from nature seawater.

High electrochemical properties of negative electrode materials are highly desirable for flexible asymmetric supercapacitors (ASCs). Although benefiting from the unique structure and broad operation potential, molybdenum disulfide (MoS2) has caused concern as a negative electrode material because its low electrochemical stability and poor conductivity hinder the exploitation of its application in flexible ASCs. Here we investigated a facile two-step hydrothermal approach to fabricate MoS2/Ketjen black (KB) composites on flexible carbon cloth. Following the construction of flower-like MoS2 on carbon cloth, KB nanospheres were embedded in MoS2 via a secondary hydrothermal route. The as-prepared MoS2/KB electrode presents a high capacitance of 429 F g−1 at a current specific of 1 A g1. In addition, the hybrid ASC device of NiCo2O4//MoS2/KB was built, which delivers a high energy density of 25.7 Wh kg−1 and power density of 16 kW kg−1. These results are ascribed to the favorable structure of MoS2 and inherently superior conductivity of KB, which improves wettability, structural stability and electronic conductivity. In brief, the proposed all-solid-state ASC device offers potential application in future portable electronics and flexible energy storage devices.

In recent years, metal-organic frameworks (MOFs), especially zeolite-imidazole frameworks (ZIFs), have been attracting widespread attention as templates for the synthesis of sensing materials. Limited researches, however, have been carried out to utilize bimetallic ZIFs in gas sensing, as the existing studies mostly involve monometallic ZIFs. Here in, the core-shell structure of ZnO and Co3O4 composite (CS-ZnO/Co3O4) was synthesized via chemical etched to Co/Zn based zeolitic imidazolate framework (Co/Zn-ZIF) with subsequent annealing. The morphology, composition and surface characteristics of the as-obtained samples were confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET). Moreover, the gas sensing measurements were implemented under various atmospheres. The response of CS-ZnO/Co3O4 sensor to 100 ppm ethanol at 200 °C achieves 38.87, which is 2.8 times that of single-shell ZnO/Co3O4 (SS-ZnO/Co3O4). The improved response is mainly attributed to the core-shell structure, which offers larger surface area, more active sites for gas diffusion and the formation of p-n heterojunction between ZnO and Co3O4.

3D Ni-Multiwall carbon nanotubes/carbon nanofibers nanostructure has received many attentions due to the large specific surface and excellent electrochemical performance. The aggregation of CNTs and high-cost manufacturing are challenges facing the preparation of hybrid 3D Ni-MWCNTs/CNFs nanomaterials. In this article, MWCNTs have grown on electrospun CNFs by using low-cost reagents and an efficient production process. The direct growth of CNTs on electrospun CNFs completed via one-step process electrospinning of Ni (AC)/PVP/PAN solution and following CVD treatment. The hybrid 3D Ni-MWCNTs/CNFs showed a large surface area of 530 m2/g higher than Ni/CNFs of 375 m2/g. The diameter of the electrospun CNFs and grown CNTs about 150 and 20 nm of hierarchical 3D Ni-MWCNTs/CNFs observed by SEM and TEM images, respectively. The hybrid structure and full carbonization were confirmed by XRD and Raman spectrums. The 3D Ni-MWCNTs/CNFs showed a comparable gas sensing properties with high response and rapid response-recovery times versus Ni/CNFs, electrospun CNFs, and commercial CNTs at RT toward 100 ppb DMMP gas (Dimethyl methyl phosphonate is a simulant gas for sarin nerve agent) with excellent selectivity. In fact, the synthetic procedure promises to be an effective approach to synthesize the hybrid 3D CNTs/CNFs nanomaterials with high sensing performance.

In this work, we have successfully prepared cubic ZnSnO3/ZnO heterostructure composite (CZS/ZO) by a one-pot hydrothermal method. This composite easily forms a hollow structure through an alkali etching process while keeping its shape unchanged. The possible growth mechanisms have been studied and the material proves to have excellent gas sensing properties. The response of hollow cubic ZnSnO3/ZnO NPs (HZS/ZO) is up to 101 in 50 ppm triethylamine (TEA) gas at a working temperature of 160 °C; the lower limit of detection is 1 ppm. Moreover, the materials exhibit high selectivity and good stability. The role of ZnSnO3/ZnO n-n heterojunction in enhancing gas sensitivity is discussed.

The electrochemical formation of Ce-Ni alloy and its nucleation mechanism were researched in LiCl-KCl melts using different electrochemical methods. Cyclic voltammetric and square wave voltammetric results indicated that the electrochemical reduction of Ce (III) appeared at a less negative value on Ni electrode than that recorded on W electrode because of the formation of Ce-Ni alloy compounds. The nucleation mechanism of Ce was found to be the progressive nucleation on Ni electrode based on Scharifker-Hill model. The change of electrode surface morphology with deposited time was observed by SEM, which indicated that the morphology of Ce deposited on Ni electrode was dendritic. Ce-Ni alloys were prepared using potentiostatic electrolysis, and checked by XRD and SEM-EDS. The results showed that hydrogen storage alloys of CeNi2, CeNi3 and CeNi5 were gained by controlling applied potential. Furthermore, the thermodynamic properties of Ce-Ni compounds were estimated in the temperature range of 823–898 K by open circuit chronopotentiometry.

Besides the urgent demand to improve the electrocatalytic performance of non-noble-metal catalysts, the decrease of catalysts load is also challenging for the radical design of electrocatalysts. In this work, porous Ni-Co-P nanosheet arrays were supported on carbon fiber cloth with an ultrathin film thickness of only ∼62 nm. The cross-linked porous nanosheet structure greatly increases the interface area of electrolytes and catalysts. The superhydrophilic and aerophobic nature is advantageous to interface contact and bubble detachment. These characteristics encourage Ni-Co-P nanosheets to maintain high performance under the condition of low active substance loading. For example, the Ni-Co-P shows superior hydrogen evolution reaction (HER) performances in both alkaline and acidic media, especially in alkaline conditions, which delivers a current density of 10 mA cm−2 at a low overpotential of 57 mV along with the Tafel slope of 69 mV dec−1. This work provides a direction for the development of low-cost and efficient non-noble metal electrocatalysts with ultralow load contents.

The reductive extraction behavior of Ln (Ce,Sm) and its on-line monitoring were explored in LiCl KCl/Bi Li system. According to calibration curve, the relationship of peak current and concentration of Ln (Ce,Sm) measured by square wave voltammetry, the calculated Ln (III) concentration is almost consistent with that analyzed by ICP-AES, and the relative average error is about 5.37%. The effects of Li content in Bi Li alloys, temperature and stirring speed on extraction rates, efficiencies and distribution ratios for Ce and Sm were determined, and found that the extraction rates, efficiencies and distribution ratios for Ce and Sm increase with the increasing the temperature, content of Li in Bi Li alloys and stirring speed. The extraction rates and efficiencies for Ln from LiCl KCl LnCl3 molten salts are higher than those for Ln from LiCl KCl CeCl3 SmCl3 molten salts, and the ones for Ce are much larger than those for Sm due to the formation of Sm (II) checked using XPS and linear sweep voltammetry. The produced Sm (II) could consume some reduced Sm metal: 2 Sm(III) + Sm = 3 Sm(II) , resulting in the decrease of the extraction rate, efficiency and distribution ratios of Sm. The experimental results showed the feasibility of on-line monitoring of reductive extraction process of Ln in LiCL-KCl/Bi Li system by electrochemical technique.

Ambient-temperature mechanical properties of isochronally aged 1420-Sc-Zr aluminum alloy were investigated. A significant grain refinement is caused with the additions of Sc and Zr. No primary Al3Sc or Al3Zr is found in as-cast 1420-Sc-Zr alloy. However, primary Al3(Sc,Zr) particles exist in as-cast 1420-Sc-Zr alloy. During the isochronal aging process, these particles of Al3Li, Al3Sc and Al3Zr begin to precipitate at 100 °C, 250 °C and 450 °C, respectively. These precipitation particles make 1420-Sc-Zr alloy obtain three peak microhardness: 845 MPa at 150 °C, 1000 MPa at 350 °C, and 985 MPa at 500 °C. The predicted strengthening increments are contrasted to the measured strengthening increment to confirm the operative precipitation mechanism at different isochronal aging. The shearing mechanism is operating in 1420 and 1420-Sc-Zr alloys aged isochronally to 150 °C. A mixed mechanism (the shearing and bypass mechanisms) is predicted to be operative in 1420-Sc-Zr alloy aged isochronally to 350 °C. The Orowan strenthening mechanism is operative in 1420-Sc-Zr alloy aged isochronally to 500 °C. During isothermal aging at 475 °C after aged isochronally to 450 °C, 1420-Sc-Zr alloy exhibits excellent thermal stability.

In this work, NiAl-LDH/Polypyrrole (NiAl-LDH/PPy) was synthesized by a simple method for the adsorption of uranium(VI) (U(VI)) from simulated seawater. The parameters studied contained pH, contact time, initial concentration and temperatures. The kinetic parameters showed that it could be well consistent with pseudo-second-order model. Langmuir and Freundlich isotherm models were used to describe the equilibrium data at three different temperatures (25, 35 and 45 °C). The result confirmed that the adsorption equilibrium tend to follow Langmuir isotherm model and the maximum adsorption capacity was evaluated to be 406.5 mg/g at 45 °C. The adsorption was a spontaneous endothermic process. NiAl-LDH/PPy also had good reproducibility and selectivity. In simulated seawater, NiAl-LDH/PPy composites showed a good enrichment effect for U(VI).

The microstructure and mechanical properties of Al-3Li-1Cu-0.1Zr-xEr (x = 0, 0.1) alloys were investigated. With an addition of 0.1 wt% Er, dispersive core-shell structure Al3(Er,Zr,Li) particles were presented and the recrystallization was restrained. Besides, the trace of dislocations bypassing the Al3(Er,Zr,Li) particles was observed. Herein, the Orowan mechanism was also verified as the main strengthening mechanism of the Al3(Er,Zr,Li) particles by comparing the theoretical value in different strengthening mechanisms with the yield strength. The result demonstrated the impeding effect of the Al3(Er,Zr,Li) particles on the planar slip induced by shearing of the Al3Li, which also corresponded to the disappearance of the plastic instability in the alloy with Er addition. The Al-3Li-1Cu-0.1Zr-0.1Er alloy aged for 56 h possessed better ultimate tensile strength of 306 MPa and yield strength of 235 MPa. Interestingly, this alloy with unremarkable planar slip manifested lower elongation of 9.4% and obvious intergranular fracture when compared to the alloy without Er. To study this specific phenomenon, the hardness of grain interior and grain boundaries was investigated. The result showed that the intergranular fracture of this alloy was induced by higher strength of the grain interior than that of the grain boundaries, while the effect of the traditional planar slip mechanism was not apparent.

In this work, superhydrophobic and superoleophilic nickel foam loaded with ZnO@Co3O4 hierarchical structure was successfully fabricated via a simplified one-pot hydrothermal method, followed by a brief calcination process and, finally, superhydrophobically modification with hexadecyltrimethoxysilan (HDTMS). The as-prepared nickel foam showed excellent abrasion resistance, chemical stability and high oil-water separation efficiency. The chemical composition and morphologies were characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The sample we have manufactured proves to be a potential material for the separation of oil-water mixtures.

A series of the rGO decorated hollow Co 3 O 4 spheres were fabricated via a solvothermal-combination-calcination process with no template. The morphological and crystal structure analysis were carried out through several characterization techniques, including SEM, TEM, XRD and XPS. The results indicate that the hollow Co 3 O 4 microspheres were assembled by nanoparticles with an average diameter of 20 nm and adhered uniformly on rGO nanosheets. According to the gas sensing test, 3 wt% rGO-Co 3 O 4 hollow spheres showed a higher substantial response to 100 ppm ethanol reaching up to 13.5, which is 3.7 times than the pristine Co 3 O 4 at 180 °C. In addition, it also exhibited short response-recovery time and good reproducibility. The enhanced sensing properties probably come from the synergy between rGO and Co 3 O 4 , mesoporous structure, and its high specific surface area (108.2 m 2 /g). This facile method could be used for the fabrication of many advanced materials for sensors, capacitors and electrodes.

A dual-phase Mg-Li-Zn alloy was processed by a severe plastic deformation method which is a method of combination of extrusion and rolling processes and enables production of a very fine grain structure. After this processing, the Mg-Li-Zn alloy exhibited a significantly large fracture elongation of 1400% at 473 K at 0.001 s−1. Moreover, an elongation of more than 600% was observed at 473 K even at high strain rate of 0.01 s−1. Also, at a lower temperature of 423 K, the alloy exhibited a large fracture elongation of 720% at 0.001 s−1. The values of the strain rate sensitivity were approximated to 0.5, which suggested that the superplastic deformation is based on grain boundary sliding. Dislocation glide is identified to be an accommodation mechanism according to the texture evolution during the superplastic deformation. The different trends of the changes of the textures in the α and β phases indicated an inhomogeneity of grain boundary sliding between phases.

Flexible and lightweight wire-shaped supercapacitors are important energy storage devices used for portable or wearable electronics. However, practical applications of flexible supercapacitors are still limited by the relatively poor performances. Herein, the hierarchical carbon cloth@CoMoO4@NiCo-LDH core-shell nanowire arrays supported have been synthesized via a facile two-step hydrothermal route coupled with annealing treatment. In addition, a possible mechanism for the growth of NiCo-LDH nanosheets (NSs) shell onto CoMoO4 nanowires (NWs) core is put forward based on the time-dependent experiments. The CC@CoMoO4@NiCo-LDH-12 h electrode exhibits a high specific capacitance of 2024 F g−1 at 1 A g−1, with 80.3% retention of the initial specific capacitance at 20 A g−1 and outstanding cycling stability. In addition, we have fabricated a flexible all-solid-state asymmetric supercapacitor (ASC) which achieves a maximum energy density of 59.5 Wh kg−1 at a power density of 800 W kg−1 and long-term cycling stability (89.7% device capacitance retention over 5000 cycles). The remarkable electrochemical performance can be ascribed to the rational combination of two electroactive materials and the reasonable array configuration.

An innovative kind of low-temperature inorganic molten salt hybrid capacitor was first put forward. Mn2O3 nanoparticle was selected as battery type positive electrode of hybrid capacitor. The high crystallinity Mn2O3 nanoparticles with large specific surface areas were successfully prepared by molten salt synthesis method using ternary alkali nitrates. Electrochemical performances of Mn2O3 electrode were evaluated by cyclic voltammetry, square wave voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge in KNO3 (53 wt%)-NaNO2 (40 wt%)-NaNO3 (7 wt%) melts at 423 K. The results illustrated that Mn2O3 electrode transferred one electron during the reduction reaction and the Mn2O3 nanoparticle exhibited a high specific capacity of 669.6 C g−1 (186.0 mAh g−1, 2.51 F cm−2) at a current density of 5 mA cm−2. Furthermore, Mn2O3 electrode exhibited excellent cycle stability, and the capacity retention was up to 90.2% after 5000 cycles at a current density of 20 mA cm−2. The hybrid capacitors with molten salt electrolyte could be considered as a potential application in some specific situation which requires the high-temperature demand.

Waste paper derived carbon coated with poly(dopamine) (WPC@PDA) as a novel adsorbent was synthesized successfully by activation of KOH and carbonization of waste A4 paper, followed by in situ polymerization of dopamine. WPC@PDA composites possessed a 3D hierarchically interconnected porous structure and the Brunauer–Emmett–Teller (BET) specific surface area is calculated to be 364.6 m2/g. The enrichment of uranium for WPC@PDA composites from not only aqueous solution (mg/L) but also simulated seawater (μg/L) was fully evaluated under different scenarios. The experimental results indicated the maximum absorption capacity to uranium (VI) of WPC@PDA composites was 384.6 mg/g at pH 7. In addition, the distribution coefficient (Kd) of U (VI) ion with other competing ions for WPC@PDA composites is 1.97 × 104 mg/L and demonstrated excellent selectivity to uranium (VI) in simulated seawater, which augurs well for the application of the adsorbent in seawater.

A high hydrophobic Ni-Cu-SiC coating with a graded nanostructure was successfully deposited on the Mg-Li alloy via electroplating and stearic acid modification. After stearic acid modification, the as-prepared Ni-Cu-SiC coating displays high hydrophobicity with contact angle of 156.0°. Furthermore, surface wettability transition from high hydrophobicity to superhydrophilicity can be achieved via UV–vis irradiation, and subsequently, the high hydrophobicity can recover to hydrophobicity via stearic acid re-modification. This work could provide a novel way to fabricate functional surface on Mg-Li alloy and wider industrial application for Mg-Li alloy.

An electrochemical study of dysprosium (III) on Bi film electrode was carried out in eutectic LiCl-KCl melts by transient and steady state electrochemical techniques. The results of transient electrochemical techniques showed that the reduction of Dy (III) appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode. The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713–803 K. Furthermore, the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities. The Bi-Dy alloys, characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction, are comprised of DyBi3/5 and DyBi phases.

In order to meet the application requirements of portable and wearable devices, the high-efficiency energy storage units with high energy density, high power density and long cycle life are urgently needed. In this work, we have successfully fabricated novel flexible electrode comprising NiCo2S4@CoMoO4 core–shell nanowire arrays on carbon cloth via a facile three-step hydrothermal process. Benefiting from the unique hierarchical structure and their synergistic effects between CoMoO4 and NiCo2S4, the supercapacitor electrode realizes a fast electron and ion transfer, a large electroactive surface area and superior conductivity. As a result, the NiCo2S4@CoMoO4 electrode exhibits superior performances with an outstanding specific capacitance of 2118.8 F g−1 at 1 A g−1 and an excellent rate capability of 81.6% at 20 A g−1. After 5000 cycles, the NiCo2S4@CoMoO4 electrode shows an excellent cyclic performance with 88.6% capacity retention. The excellent performance of electrode is also confirmed by assembling all-solid-state asymmetric supercapacitor, which delivers a high energy density of 66.6 Wh kg−1 as well as the maximum power density of 16 kW kg−1. This work demonstrates that the NiCo2S4@CoMoO4 electrode provides a promising material for the energy storage applications in the future.

Higher strength is always the goal pursued by researchers for the structural materials, especially for the lightweight magnesium (Mg) alloys which generally have relatively low strength at present. From this aspect, the present paper reviews the recent reports of a kind of Mg alloys, i.e. Mg-RE (RE: rare earths, mainly Gd or Y) casting and wrought alloys, which have been able to achieve high strength compared with common or commercial Mg alloys, from the viewpoint and content of the alloy system, alloying constitution, preparation process, tensile strength and each of the main strengthening mechanisms. This review of recent research and developments in high-strength Mg-RE alloys is beneficial for the further design of Mg alloys with higher strength as well as excellent comprehensive performance. Keyword: Mg alloys, High strength, Rare earths (RE), Strengthening mechanism

The impact of different rolling orientations (0°, 45° and 90°) on the microstructure, mechanical, in-plane anisotropy (IPA) and gamma rays (γ-rays) shielding properties of a lately developed Al-Cu-Li-Mg-X (X = Mn, Zr, Zn) alloy was investigated. The results showed that rolling along several directions corresponded to distinctive microstructures, which considerably affected the properties. The main strengthening phases in the alloy were δ'(Al3Li), Al3(Zr,Li) and T1(Al2CuLi), while the strengthening effect of the T1 precipitates was predominant. The main precipitates were δ'(Al3Li), minor Al3(Zr,Li) and coarse T1(Al2CuLi) phases when rolled along the 0° direction, a large amount of fine T1(Al2CuLi) phase with few δ'(Al3Li) and Al3(Zr,Li) precipitates by rolling along the 45°direction, besides, a large amount of the Al3(Zr,Li) phase with minor δ'(Al3Li) in the alloy rolled along the 90° direction. The alloy rolled along the 90° orientation exhibited the appropriate isotropic mechanical behavior, which was caused by the homogeneously distributed dislocations that produced a homogeneous dispersion of the strengthening precipitates in the three tensile angles. In addition, the shielding property showed different screening ratios when varying the rolling direction. The 90° rolling direction presented the most desirable shielding property.

AZ31 magnesium matrix composites reinforced by nickel coated graphene nanoplatelets (denoted as Mg-3wt.%Al-1wt.%Zn-0.5 wt% GNPs) were fabricated with vacuum hot-press sintering process. The sintered compacts were then hot extruded at 390 °C. The microstructure, mechanical properties and wear performance were investigated. The results show that, the nickel coated GNPs uniformly distribute in the matrix. The compressive strength, microhardness, the coefficient of friction and wear rate of the composites are noticeably improved, compared to the matrix alloy of AZ31. GNP content is the main factor affecting the wear behavior of composites, and the addition of GNPs resulted in a significant increase of the abrasion resistance and a decrease of the friction coefficient.

Electrochemical co-reduction of Mo(VI) and S(II) was studied in LiCl KClKCl(NH4)6Mo7O24 KSCN melt, and the molybdenum disulfide (MoS2) with specially structures of flower-like and sheet-like molybdenum disulphide was successfully synthesized by molten salt electrolysis. This study investigated the influences of KSCN concentration, experimental temperature and current density on the formation of MoS2, and the controllability of MoS2 microstructure was successfully realized by adjusting the experimental temperature and current density. Simultaneously, the electrochemical behaviors of Mo(VI) and S(II) in the melt were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV) and open-circuit chronopotentiometry (OCP). All of the MoS2 samples obtained by electrochemical co-reduction Mo(VI) and S(II) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), high-resolution TEM (HRTEM) and pin-on-disc friction and wear machine, respectively. The results from tribological properties tests illustrated that MoS2, as a solid lubricant, has the low friction coefficient and good wear resistance. The friction coefficient of flower-like MoS2 is around 0.119.

Effects of annealing temperature and annealing time on the microstructure, interfacial bonding properties and mechanical properties of alternate α/β Mg-Li alloy composite plates by accumulative roll bonding (ARB) were investigated. Due to the large reduction, a part of the relatively harder Mg-5Li-1Al alloy is embedded into the softer Mg-12Li-1Al alloy to achieve metallurgical bonding in the process of composite rolling. The optimum annealing temperature of the composite plate is 350 °C or 400 °C. At the same time, the formation mechanism of the interfacial diffusion region was discussed, and results show that there exist two diffusion regions, diffusion layer 1 and diffusion layer 2. The diffusion layer 1 is mainly composed of Li3Mg7 phase, and the diffusion layer 2 is composed of Li0.92Mg4.08 phase. The interfacial bonding ability of Mg-Li alloy composite plate first increases and then decreases with the increase of annealing temperature and annealing time. Compared with the composite plate processed by one pass ARB, the annealing time of the composite plate processed by six passes ARB increases due to the increase of cumulative strain, and the optimum annealing process is at 400 °C for 30 min.

The effects of the Cu/Mg ratio on the microstructure, properties and fracture morphology of Al-Li-Cu-Mg-X (X = Mn, Zr, Zn) alloys were investigated. The results showed that the modification of the alloy composition with different Cu/Mg ratios significantly corresponds to various microstructures, which affects the corrosion resistance, hardness and tensile properties. For instance, when the Cu/Mg ratio varies from 0.83 to 4.33, the ultimate tensile strength of the Al-Cu-Li-Mg-X alloys gradually increases from 267.2 to 366.6 MPa. Corrosion tests revealed that increasing the Cu/Mg ratio markedly enhances the corrosion resistance of the alloy. The constitution and morphology of the precipitates are also found to vary with the Cu/Mg ratio. The main precipitates are δ'(Al3Li) and the minor TB(Al7Cu4Li) phase when the Cu/Mg ratios are 1 and 0.83. By increasing the Cu/Mg ratio to 2.35, the θ'(Al2Cu) phase can be detected, while only the T1(Al2CuLi) phase is detected in the alloy with the highest Cu/Mg ratio. The combinative hardening of the T1, TB, θ' and δ' precipitates is responsible for the improvement in the mechanical properties and corrosion resistance of the alloy with the highest Cu/Mg ratio. During the tensile testing, the failure mode is converted from a typical shallow dimple fracture to an intergranular-dominated mixed one with the decrease of the Cu/Mg ratio.

Ultrafine-grain and high-strength Mg-5Li-1Al sheets were prepared by accumulative roll bonding (ARB) process. Evolution of microstructure and mechanical properties of ARB-processed Mg-5Li-1Al sheets was investigated. Results show that, during ARB process, the evolution of deformation mechanism of t Mg-5Li-1Al alloy is as follows: twinning deformation, shear deformation, forming macro shear zone, and finally dynamic recrystallization (DRX). The grain refining mechanism changes from twin DRX to rotation DRX. With the increase in ARB cycles, strength of the Mg-5Li-1Al sheets is enhanced, whilst elongation varies slightly. With the increase in rolling cycles, anisotropy of mechanical properties decreases. It is conclusive that strain hardening and grain refinement dominate the strengthening mechanism of Mg-5Li-1Al alloy.

The electrochemical behaviour of Zr(Ⅳ) ions in LiCl-KCl molten salt solutions was investigated via different electrochemical techniques on W-inert and Cu-active electrodes. It was established that the electrochemical reduction process on inert electrode proceeds in two consecutive stages. The composition of Cu-Zr intermetallic compounds formed on an active copper electrode was determined, and the specific thermodynamic characteristics of the formed intermetallic compounds were calculated. The progressive nucleation of Zr was determined based on the comparison between experimental results and theoretical values of the two nucleation models. Finally, the metallic Zr and Cu5Zr alloy were successfully extracted from the molten salt via potentiostatic electrolysis.

With the continuous development of the nuclear industry, there is an urgent need to find a method that can safely and efficiently dispose of spent resins. Molten salt oxidation (MSO) is a promising waste treatment technology. In this paper, the newly shipped resins were used to simulate the actual spent ion exchange resins. The destruction of the resins is mainly divided into three stages. The addition of oxygen can increase the activation energy (E) required for the reaction. Some solid residues which were proved to be amorphous carbon materials generated after MSO. In the high-resolution XPS spectra of C 1s, the C-S bond disappeared after MSO at 400 ℃ for 2 h proved the destruction of the sulfonic acid groups. The core-level scan XPS spectra of S 2p illustrated that sulfur and sulfonyl bridges were formed after sulfonic acid groups were destroyed. The infrared spectrum also showed that the sulfonic acid groups were destroyed at 400 ℃ to form sulfonyl structure, but sulfur bridges were not found due to its small IR absorptions. In this paper, the ternary eutectic Li2CO3-Na2CO3-K2CO3, can be operated efficiently at a relatively low temperature. The generated sulfur dioxide is captured by the carbonate to form sulfate. These merits make MSO become a promising and environmentally friendly approach for the treatment of sulfur-containing organic waste.

Ionic liquids are widely employed as electrolytes for electrochemical oxygen sensing due to their excellent physical and chemical properties. Recently, combining inorganic electrochemically active materials with ionic liquids are becomes intensively interesting to improve oxygen sensor performance. In this paper, two imidazolyl-based ionic liquids 1-ethyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Emmim][TFSI] and 1-butyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Bmmim][TFSI] with three saturated alkyl substituents on the aromatic ring were prepared by a traditional two-step method. Under the electrochemical test, both ionic liquids exhibit a certain responsibility to different concentrations of oxygen. Subsequently, α-Fe2O3/rGO was prepared by hydrothermal method and then mixed with the ionic liquids to prepare a composite ionic liquid electrolyte for detecting a wide range of oxygen concentrations. The response performance of prepared composite electrolyte toward the oxygen is improved, which exhibits a sensitivity of 0.1041 μA/[%O2] to gradually changed oxygen concentration and a linear correlation (R2) of 0.9997 between oxygen reduction peak currents. Hence, the results show that the pure ionic liquid has a certain ability to detect oxygen, while adding α-Fe2O3/rGO compounds further improve responsibility, stability and sensitivity of composite electrolyte to oxygen.

Mechanical properties and thermal conductivity of Mg-2Zn-Zr alloy were adjusted with mill-annealing and subsequent aging process. The alloy with preferable thermal conductivity, larger than 130 W/(m K), and mechanical properties was obtained. The microstructure, mechanical properties and thermal conductivity are investigated. The average grain size is reduced to 7.8 μm after mill-annealing with a reduction of 75%. The phases of MgZn and ZnZr exist in the as-cast alloy. After aging, the main precipitated phases are ZnZr, Zn 2 Zr and Zn 2 Zr 3 . The precipitation of MgZn is inhibited. The tensile strength is improved by mill-annealing and aging. The peak aged alloy with a rolling reduction of 50% possesses a tensile strength of 279 MPa, a yield strength of 196 MPa and an elongation of 25.2%. The thermal conductivity of the alloy is 132.1 W/(m K). The Mg-2Zn-Zr alloy after mill-annealing and subsequent aging process is a potential preferable thermal conductivity material.

High magnetism and magnetization intensity are required for preparing rare-earth-based single-crystal flaky magnetic intermetallic compound materials. Herein, we report high coercivity Sm-Co (Sm2Co17, SmCo5, Sm2Co7, SmCo3, and SmCo2) intermetallic compounds, which have been synthesized by electrochemical synthesis in LiCl-KCl-SmCl3-CoCl2 melt. The electrochemical co-reduction behaviors of Sm(III) and Co(II) ions, and the formation of intermetallic compounds in the melt were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV) and open-circuit chronopotentiometry techniques (OCP), respectively. The crystal nature of Sm-Co intermetallic compounds was characterized by X-ray diffraction (XRD), selected area electron diffraction (SAED), high-resolution transmission electron microscopy (HRTEM) and Fast Fourier transform analysis (FFTs) method. At the same time, multilayer planar structure of Sm-Co intermetallic compounds was investigated by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The results showed that as the mass percentage of SmCl3 changed from 0 to 12 wt.%, the phase of Sm-Co intermetallic compounds transferred from Co-rich side to Sm-rich side, and the crystal structures were found to be single-crystal ones. The valence bands and core levels of Sm-Co intermetallic compounds were evolved in the crystal growth process. A structural change in the core levels Sm 3d and Co 2p during the course of transition from pure components to intermetallic compounds occurred, which could be explained by the hybridization of f and d electrons of samarium and cobalt. The results of Sm-Co intermetallic compounds for vibrating sample magnetometer (VSM) test showed that the magnetic densities of Sm2Co17 and SmCo5 were 157 emu/g and 145 emu/g, respectively.

The electrochemistry of praseodymium was studied on liquid Zn film electrode in LiCl-KCl eutectic melts by transient electrochemical techniques. Cyclic voltammogram and square wave voltammogram showed that eight reduction peaks, corresponding to the formation of eight Pr-Zn intermetallic compounds, were observed at less negative potential values, which indicated the underpotential deposition of praseodymium occurs on liquid Zn film electrode. Thermodynamic properties on the formation for Pr-Zn intermetallic compounds, such as activities and relative partial molar Gibbs free energies of Pr in two-phase coexisting states as well as the standard Gibbs free energies of formation for Pr-Zn intermetallic compounds, were estimated using electromotive force (emf) measurement in the temperature range from 723 to 873 K. Electrochemical preparation of Pr-Zn alloys was executed by potentiostatic and galvanostatic electrolysis on Zn film electrode and liquid Zn pool electrode, respectively. X-ray diffraction (XRD) indicated that Pr-Zn alloy were comprised of different Pr-Zn intermetallics. The surface microstructures and micro-zone chemical analyses of Pr-Zn alloys were also characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results of SEM-EDS displayed that the distribution of Pr is non-homogeneous in Pr-Zn alloys.