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The UV-C emission with a spectral range of 200–280 nm is of paramount importance in the germicidal and medical applications for disinfection, sterilization, and deactivation of microorganisms such as bacteria and virus considering current global pandemic crisis of coronavirus (COVID-19). Such intense UV-C radiation (4.4–6.2 eV) can be often generated using Pr3+ activators (as a result of their electronic transition [Xe]4f15d1→[Xe]4f2) doped in crystalline inorganic host matrices. In this regard, Pr3+-activated rare earth phosphates have been intensively studied as a model system of UV-C emitters thus far. Here, we have prepared three different representative crystalline UV-C phosphors of YPO4:Pr3+ (tetragonal), LaPO4:Pr3+ (monoclinic), and La-substituted YPO4:Pr3+ (tetragonal), respectively, and further investigated the effect of La substitution in YPO4 crystal structures on UV-C emitting properties. The structural lattice distortion in the local environment of activator Pr3+ cations induced by La substitution indeed impacts on the UV-C emitting properties. Small amount of substitutional doping of La3+ (ca. 5 mol.%) in Y site of YPO4 enhances the UV-C emission intensity by a two-fold of magnitude recorded under 225 nm excitation (photoluminescence) and cathode ray (cathodeluminescence). This finding can provide a fundamental designing principle of inorganic phosphor materials to enhance the emitting properties of activators, directly influenced by local environment and symmetry of the crystal structures.

The rapid technological progress in the 21st century demands new multi-functional materials applicable to a wide variety of industries. Two-dimensional (2D) materials are predicted to have a revolutionary impact on the cost, size, weight, and functions of future electronic and optoelectronic devices. Graphene, which shows potential as an alternative to conventional conductive transparent metal oxides, may play a central role. Since its work function (WF) is tunable, graphene exhibits the interesting ability to serve two different roles in electronic and optoelectronic devices, both as an anode and a cathode. After introducing some basic concepts, this work reviews the most important advances in controlling the tuned WF of graphene, highlighting special features of graphene electronic band structure and recognizing different methods for measuring WF. The impact of thickness, type of contact, chemical doping, UV and plasma treatments, defects, and functional groups of graphene oxide are considered and related with the applications of the modulated material. The results of the review, organized in lookup tables, have been used to identify the advantages and main challenges of the tuning methods. This work was supported by Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades of Spain) under the project ESP2017-82092-ERC (AEI). SN work is supported by Comunidad de Madrid (Spain) under the Grant 2018/T2IND/11352.GSA work is supported by the Ministerio de Ciencia, Innovación y Universidades of Spain under the Grant RYC-2014-15357.

Stable and high-efficiency narrow-band green phosphor is a key component for wide color gamut liquid crystal display (LCD) backlights. In this paper, narrow-band green-emitting Sr3-3xSi13Al3O2N21:3xEu2+ (0.001 ≤ x ≤ 0.09) (Sr-Sialon:Eu2+) phosphor with a full-width at half maximum of 66 nm has been successfully synthesized by using the solid-state reaction method. All the samples are the pure phase with Sr3Si13Al3O2N21-type structure. Their emission band maximum can be tuned from 495 to 523 nm by increasing Eu2+ content. The compound with x = 0.03 possesses the highest luminescence intensity with the peak position around 510 nm. Luminescent thermal stability gets better with Eu2+ concentration decreasing. The integrated intensity of the sample with x = 0.01 at 425 K remains about 80% of the intensity at room temperature. The host referred binding energy (HRBE) and vacuum referred binding energy (VRBE) schemes are constructed to further explain its luminescent thermal quenching mechanism. White light-emitting-diode (w-LED) device using optimized Sr2.91Si13Al3O2N21:0.09Eu2+ phosphor demonstrates its potential application for LCD backlights.

Novel plate-like B-site complex Bi4(ZrxTi1-x)3O12 microcrystals consisted with both (Bi2O2)2+ layer and Zr4+substituted [Bi2Ti3O10]2- blocks have been synthesized through molten salt method. With the increase of Zr4+ content, the lattice constant of Bi4(ZrxTi1-x)3O12 increases. From the Raman analysis, the bending vibration was mainly influenced by the Zr4+ content, while both of bending and stretching vibration was influenced at relative high calcination temperature. The reaction conversion process was mainly controlled by the solution-precipitation mechanism and TiO2 provided the basis crystal nucleation in NaCl-KCl molten salt, where the reactant ionic can precipitation, epitaxial growth and finally generated the final bismuth layer-structure products. Finally, fine crystallinity and orientation of plate-like Zr substituted Bi4(Zr0.1Ti0.9)3O12 microcrystals with high aspect ratio can be successful fabricated at 900 °C, which paved a way to design and fabricate the novel plate-like B-site complex perovskite compounds in the future.

The magnetic properties of MgO thin films were discussed as an interplay among the oxygen vacancies, Mg2+ ion coordination and structural order deposited using radio frequency (RF) sputtering method by varying substrate temperature and deposition power followed by in-situ annealing. Rutherford backscattering spectrometry (RBS) and high resolution transmission electron microscopic (HRTEM) performed for these films showed decrease of film thickness with increase of substrate temperature. Films are thicker for higher sputtering powers at corresponding substrate temperatures. Spectral features in Mg K-edge near edge X-ray absorption fine structure (NEXAFS) spectra are characteristics of MgO for both sputtering powers at substrate temperature of room temperature (RT) and 350 °C. O K-edge NEXAFS spectra exhibited onset of oxygen vacancies as inferred from pre-edge region. Magnetization versus applied magnetic field curves for these films showed onset of do ferromagnetism. This behavior ceased with increase of substrate temperature, however, become dominant with increase of sputtering power. Magnetic behavior was dominant for the films which had slightly distorted Mg2+ ion co-ordination. The existence of oxygen vacancies was not observed to be consistent with magnetization. Thus, this study envisaged the role of Mg2+ ion coordination, long range structural order and oxygen vacancies in order to determine magnetism in these systems.

The present work shows the properties of BaTiO3:Ho3+ and BaTiO3:Ho3+/Yb3+ phosphors, prepared by the sol-gel method. The samples were characterized by powder X-ray diffraction (PXRD), Raman spectroscopy and scanning electronic microscopy (SEM). Upconversion (UC) and second harmonic generation (SHG) were monitored by photoluminescence. The UC mechanism was studied by time-resolved spectroscopy. Through PXRD, it was possible to determine that all synthesized phases crystallized in a cubic perovskite-type structure. Raman spectra corroborated the coexistence of both cubic and tetragonal phases. For the BaTiO3:Ho3+ samples excited at 1200 and 1150 nm, the emission spectra exhibited only one peak corresponding to the second harmonic of the emission wavelength. On the other hand, for the BaTiO3:Ho3+/Yb3+ samples excited at 975 nm, the emission spectra exhibited an intense green band at 554 nm, a medium intensity red band at 665 nm and a weak band at 760 nm. The study of the dependence of UC emission intensity on the pump power of the incident laser and the decay curves of red and green emissions were used to elucidate the UC mechanism, which corresponded to the process known as ground state absorption/energy transfer upconversion.

NiCo2O4, as a typical battery material, has been researched in LIB and hybrid supercapacitors. The electrochemical performance of NiCo2O4 is greatly influenced by its morphology. Interestingly, alkaline substances play a vital role in the morphology formation of NiCo2O4. Therefore, it's necessary to study the effect of alkaline substances on the morphology of NiCo2O4. In this work, nanosheet-like, ball-like and urchin-like NiCo2O4 are formed by sodium hydroxide, ammonium hydroxide and urea. Nanosheet-like NiCo2O4 formed by sodium hydroxide exhibits the most outstanding electrochemical performance. Northworthy, huge morphological changes emerge while tailoring the concentration of sodium hydroxide. Nanorod-like NiCo2O4 appears at the sodium hydroxide concentration of 0.025 M. It also displays high capacity of 866 C g−1 at 1 A g−1 and superior cycle stability with 95% capacitance retention after 10000 cycles. In the practical application, coin-type hybrid supercapacitors deliver maximum energy density of 57.78 Wh kg−1 and power density of 8000 W kg−1.

Bifunctional Z-scheme AgIn 5 S 8 /Bi 2 WO 6 nano-heterojunctions with excellent performance for photocatalytic degradation of refractory pharmaceutical contaminants and reduction of aqueous Cr(VI) were synthesized by solvothermal method. The photocatalytic degradation performance of AgIn 5 S 8 /Bi 2 WO 6 heterojunctions is related with the AgIn 5 S 8 content, and the optimal decomposition efficiency of tetracycline hydrochloride (TC•HCl) aqueous solution by 10% AgIn 5 S 8 /Bi 2 WO 6 under visible-light irradiation reached 92% within 2 h, which is much higher than that of single AgIn 5 S 8 (53%) and Bi 2 WO 6 (67%) nanoflower. The highest photocatalytic degradation performance of 10% AgIn 5 S 8 /Bi 2 WO 6 nano-heterojunction can be put down to the most efficacious separation of photoexcited electrons and holes, and the extremely positive valence band potential of Bi 2 WO 6 . The reduction efficiency of Cr(VI) by 10% AgIn 5 S 8 /Bi 2 WO 6 heterojunction is more than two times that of pure Bi 2 WO 6 , while is still lower than that of pure AgIn 5 S 8 , which can be interpreted by the Z-scheme path of e-h transfer in AgIn 5 S 8 /Bi 2 WO 6 heterojunctions and the further oxidation of Cr(III) by hydroxyl radicals. The COD removal efficiency of pharmaceutical industry wastewater by the photocatalysis of Z-scheme AgIn 5 S 8 /Bi 2 WO 6 heterojunctions reached 77%, indicating that the developed Z-scheme AgIn 5 S 8 /Bi 2 WO 6 heterojunctions are promising in efficacious disposal of refractory pharmaceutical contaminants and Cr(VI) in water.

In this work, Cu–10Sn/SiC composite has been manufactured using powder metallurgy method and its microhardness and corrosion resistance have been evaluated. For this, Cu–10Sn and SiC powders with various ratios were mixed, molded and sintered. Optical microscope, SEM and EDX were applied for study of SiC particles distribution in Cu–10Sn matrix and interfaces between them. Results of microhardness and electrochemical measurements revealed that incorporation of silicon carbide particles in Cu–Sn bronze matrix increase the microhardness and corrosion resistance and the composite containing 10 wt% SiC has the highest microhardness and corrosion resistance in 3.5 wt% NaCl solution. High hardness and chemical stability of SiC particles, perfect matrix/second phase particles interfaces and acceleration in protective layer nucleation and formation by incorporation of SiC particles in bronze matrix were recognized as the main reasons for these properties improvements. Above 10 wt%, incorporation of SiC particles lowers the microhardness and corrosion resistance due to the agglomeration of these particles and incomplete sintering of the specimens.

Enhancing the fluorescence and thermo-mechanical properties of rare-earth doped aluminosilicate glasses (AS) by modifying the chemical composition with different alkaline earth oxides opens new opportunities for their application as optical devices. This paper provides a study on 1 × 1020 ions/cm3 Sm3+ doped aluminosilicate glasses, with the network modifier oxides BaO, SrO, CaO, MgO (35 mol%), Al2O3 (10 mol%) and SiO2 (55 mol%), denoted as BaAS, SrAS, CaAS and MgAS, prepared by the melt quench technique. Based on the measured UV–visible and NIR absorption spectra, the Judd-Ofelt parameters Ωλ, (λ = 2, 4, 6) were evaluated to predict the radiative properties of Sm3+ ions such as radiative transition probabilities (Arad), radiative lifetimes (τrad) and branching ratios (βR). By using the Fuchtbauer-Ladenburg (FL) formula, the gain cross sections were calculated from the stimulated emission cross sections. The glass BaAS has the highest value of Ω2 which corresponds to a high asymmetry at the rare earth sites and the glass MgAS has the highest values of Ω4 and Ω6 which corresponds to a high rigidity and a low optical basicity of the glass. The same glass has the highest quantum efficiency and the highest gain cross section values of the investigated glasses. On the other hand, the glass BaAS has the smallest efficiency and gain cross section, however, it provides the lowest glass transition temperatures which would be beneficial for the production of high-quality glass. Raman spectra of the AS glasses show a broader variation of Qn species and an increasing depolymerization for glasses with network modifier ions of larger ionic radii.

Novel core-shell-shell Fe@SiO 2 @(MnZn)Fe 2 O 4 soft magnetic composites (SMCs) with low core loss and high permeability were fabricated by a facile continuous chemical co-precipitation route and subsequent powder metallurgy technique. The typical double-shell structure for Fe@SiO 2 @(MnZn)Fe 2 O 4 powders was composed of a SiO 2 −(MnZn)Fe 2 O 4 mixed outer layer and an SiO 2 inner network embedded with trace amounts of (MnZn)Fe 2 O 4 . In comparison with Fe@SiO 2 SMCs, the Fe@SiO 2 @(MnZn)Fe 2 O 4 SMCs presented a notable flat high frequency characteristic up to 1 MHz, much higher permeability, and lower core loss which reduced with decreasing (MnZn)Fe 2 O 4 layer thickness. Fe@SiO 2 @(MnZn)Fe 2 O 4 SMCs prepared with 4 mL (MnZn)Fe 2 O 4 solution exhibited stable permeability of 64.0–63.5 up to 1 MHz and low core loss of 0.9–30.6 W/kg in 1–150 kHz. The strong magnetic coupling between the thin (MnZn)Fe 2 O 4 layer and Fe cores effectively reduced the air-gap thickness and demagnetization field giving rise to a high permeability. The low core loss could be attributed to the full separation of Fe core by thin dielectric−electrically insulating magnetic coupled with a SiO 2 /(MnZn)Fe 2 O 4 insulating layer. Our findings might shed insight on the design of novel SMCs with low core loss and high permeability.

This work describes a facile one-step method to synthesize PbS hierarchical architectures with excellent supercapacitive performance. The as-prepared PbS sample shows a self-similar fern-like morphology. A unit has four or eight micro-trunks with the size of 10 ± 1 μm, which consist of ordered secondary nano-leaves with the thickness of 200 ± 20 nm and the spacing of about 100 nm. The fractal fern-like PbS sample owns a high specific capacitance of 498 F/g at a discharge current density of 2 A/g, while the value still retains 74% (369 F/g) at a big discharge current density of 20 A/g. The equivalent series resistance of the as-prepared sample is only 1.05 Ω. Moreover, the fractal fern-like PbS sample exhibits a surprising long-term durability which can keep 95.9% capacitance retention over 60,000 charge/discharge cycles at a charge/discharge current density of 5 A/g. The as-prepared PbS sample shows a stable energy density of 11.5 Wh/kg at the power density of 200 W/kg, and still remains 8.2 Wh/kg at 4000 W/kg.

In this paper, we report the fabrication of 90W–7Ni–3Fe refractory alloy using a novel oscillating pressure sintering (OPS) technique. The technique is similar to conventional hot pressing (HP), excepting that an oscillating pressure replaces the static pressure in HP. The results show that compared to HP, OPS can significantly improve the sintering ability of the alloy by decreasing the sintering temperature required for the densification of the alloy and inhibiting grain growth. The sample obtained at 1250 °C exhibits an HV hardness of 450 HV0.5, which is not only much higher than that for the HP prepared sample, but also much higher than materials with similar compositions ever reported. The results clearly demonstrate that OPS is a very promising technique for the fabrication of high performance refractory alloys.

Rather than preventing the dissolution and diffusion of polysulfides, promoting polysulfide conversion through improved polysulfide redox is another promising strategy to suppress the dissolution of polysulfides and enhance the cycle life of sulfur cathodes. We demonstrated that VO2-rGO not only facilities liquid-involving polysulfide redox (Li2S8→Li2S6→Li2S4), but also promotes the effective decompositions of lithium sulfide (Li2S). As evidenced by the visual experiments and DFT calculation, VO2-rGO has strong affinity for polysulfides species. With sulfur loading of 2.15 mg cm−2 and sulfur content of 76 wt%, the reversible capacity retained at 896 mAh g−1 after 200 cycles.

In the present study, the effects of strain paths (i.e., single-pass and multi-pass hot compression) on microstructural and texture evolutions of AZ80 magnesium alloy were studied at temperature of 350 °C and strain rate of 0.01 s−1. The results showed that flow stresses are remarkably dependence on strain path changes. Flow stress hardening phenomenon during interrupted holding of multi-pass hot deformation was observed, which led to higher peak stress of next pass than previous unloading stress. Strain paths presented slight influence on grain size. Significant contribution of strain paths to texture evolution was found. Due to dynamic recrystallization and meta-dynamic recrystallization, texture components gradually changed from ( 1 ¯ 2 1 ¯ 0 ) and ( 01 1 ¯ 0 ) in single-pass deformation to (0001) 01 1 ¯ 0 > and (0001) 11 2 ¯ 0 > in four-pass deformation. The observed flow stress hardening phenomena were interpreted by the combined functions of grain coarsening and texture evolution.

The crystal structure and magnetic properties of Pr 1- x Ca x MnO 3 (PCMO) were investigated systematically. It is shown that the symmetry of the structure is improved with the increase of Ca 2+ ions. At the same time, the distortion of the MnO 6 octahedron is reduced due to the weakening of the Jahn-Teller (J-T) effect in the system. Magnetic characterization shows that the original ferromagnetic (FM) at the low doping range ( x = 0.2, 0.3) begins to appear antiferromagnetic (AFM) at the half doping range ( x = 0.4, 0.5). Such magnetic transition is derived from the dynamic competition between the double exchange (DE) effect and the super exchange (SE) effect. These two exchange effects are significantly affected by structural distortions and charge-ordered (CO) phases. The coexistence and transition of multiple magnetic states embody complex internal competition in PCMO. Analysis of its intrinsic mechanism is helpful for designing spintronic devices.

In this study, aluminum matrix composites (AMCs) were developed using two different techniques, conventional stir casting and ultrasonic assisted stir casting. The drawbacks of the conventional stir casting technique were eliminated by employing an alternative process to produce the composite, wherein ultrasonic energy was introduced into the molten metal using an ultrasonic probe. AMCs were produced by using different concentrations of SiC (3%, 5%, 8%, and 10%) microparticles with a size of 40 μm. Mechanical and physical properties of the composites developed using both techniques were examined and compared. Moreover, the effect of filler inclusion on AMC density was assessed. The microstructural investigation revealed that SiC microparticles were dispersed homogeneously in the matrix material when the ultrasonic probe was used. Furthermore, test results indicated that mechanical and physical characteristics improved with the ultrasonic-assisted stir casting process.

We demonstrate the highly promising p-i-p InAs/GaAs quantum dots based infrared photodetector (QDIP) which utilize intra-valence band hole transitions as against electron transitions operating at high temperatures. The photoluminescence spectroscopy at 9 K exhibited the ground state emission peak at 986 nm. The spectral response measured reveals the short wave infrared (SWIR) detection with a high-intensity peak at a wavelength of 2 μm. The measured dark current density at 77 K was 0.448 A/cm2 for an applied voltage of −1 V. The spectral response peak and blackbody signal measurements were recorded up to 245 and 270 K, respectively. Fabricated detector exhibited high confinement energy of 82.1 meV measured using temperature dependent current-voltage characteristics. We report high temperature infrared detection at 225 K in the short wave infrared regime with a peak responsivity of 3.813 A/W and a specific detectivity of 2.189 × 1010 cmHz1/2/W. In order to study the electronic properties of InAs/GaAs QD, a theoretical model is developed in which Vegard's law is applied to solve 3D-Schrodinger equation, which makes use of concentration-dependent equations for light hole and heavy hole masses instead of the effective mass approximation of holes. This study demonstrates the necessity of exploring hole-transitions rather than the conventional electron-transitions in QDIPs in order to achieve high temperature of operation and improved device efficiency.

Mesoporous NiCo2S4 materials with high specific surface area and suitable mesopores display excellent supercapacitor performance due to rich electroactive sites and short diffusion paths. Here, the mesoporous NiCo2S4 microaggregates composed of nanoparticles are first successfully prepared by a simple anion exchange method to puff NiCo2O4 cubes. The NiCo2S4 microaggregates possess rich mesoporous structure with high surface area of 63.79 m2 g−1 and suitable pore size distribution centered at 6.1 nm. The NiCo2S4 microaggregates deliver high specific capacity of 249 mAh g−1 (at 1 A g−1) and good rate capability of 56.2% capacity retention from 1 to 20 A g−1. The fabricated NiCo2S4//AC ACS exhibits a prominent energy density of 47.9 Wh kg−1 at a power density of 783 W kg−1 and immensely distinguished cycling stability (98.8% retention of the initial capacitance after 4000 cycles). These remarkable performances can corroborate superiority of the mesoporous structure for improving supercapacitor electrode properties.

The inception of flexible supercapacitors that can work steadily under large deformation has been a research hotspot in recent years. To improve the device's stability, one needs to find innovative solutions to inevitable delaminations of electroactive components, which are resulted by relative displacement under external force. Herein, an extensive all-in-one hydrogel-based supercapacitor is designed. Based on the special physical properties of hydrogels, the polypyrrole-polyvinyl alcohol/dilute sulphuric acid-polypyrrole (PHP) sandwiched device shows the harmonious mechanical and electrical properties. When the tensile strain of PHP reaches to 110%, the areal capacitance still maintains at 90%. Similarly, the high areal capacitance retention under compression and twisting also verifies that the PPy active layer tightly permeates and adheres to the PVA-H2SO4 electrolyte layer. In addition to the fascinating mechanical properties, the undetectable contact angle reveals a superhydrophilic surface which is beneficial to provide an easy access for electrolyte ions, thus enhancing the electrochemical performance. Moreover, a stable cycle performance (97% after 10000 cycles) is obtained due to the excellent water retention ability which prevents the loss of electrolyte. The maximum extended voltage window is 1 V with the power density of 500 μW cm−2 (the energy density of 6.94 μW h cm−2). These hydrogel-based supercapacitors can be immune to the harm caused by external forces and maintain good mechanical integrity and electrochemical stability. Developing the hydrogel-based supercapacitors can provide a fresh perspective on multifunction applications and herald a new territory for flexible energy storage devices.

Bulk sintered SmFe 11 Ti-based magnets with high energy density have not been realized yet despite three decades of research efforts. In order to move a step forward in this direction, in this work we demonstrate a process for producing fine, anisotropic, single-crystalline SmFe 11 Ti-based particles with high roundness by using jet-milling. Particle size of 2.7 ± 0.6 μm is realized in the case of Sm(Fe 0.8 Co 0.2 ) 10.5 Cu 0.5 Ti composition. XRD results show that the ThMn 12 phase is preserved during milling, whereas peaks from the intergranular phases vanish indicating partial removal and amorphization as confirmed by TEM studies. Increased roundness can be achieved by optimizing feeding rate and grinding gas pressure, which is beneficial for local demagnetization field reduction according to micromagnetic simulations. Grain boundary infiltration experiments using low-melting alloys enable liquid-phase sintering at a temperature as low as 500 °C. The resultant bulk samples are anisotropic and show full density, although coercivity remains only 0.32 T. The possible reasons are linked to defects in the microstructure, where formation of slip bands lead to Sm vacancies and can lower the local magnetocrystalline anisotropy and the coercivity. It was found that the volume fraction of the defects can be reduced by low temperature annealing of the jet-milled powders.

In this paper, porous NiO with three-dimensional (3D) nanostructures are prepared by a chemical bath deposition (CBD) process in oxalic acid solution at a fixed temperature using Ni foam (NF) as the substrate and Ni source, and followed by an electrochemical activation treatment in an alkaline medium. The special 3D porous structure of the as-prepared NF based NiO (NiO/NF) electrode is benefit for the diffusion of fuels (CH3OH/C2H5OH and urea) during the electrochemical reaction. Besides, the obtained NiO may combine with the remained nickel oxalate (NiC2O4) to further enhance the catalytic performance due to its synergistic effect. At 0.60 V, the electrooxidation current density reached 257 mA cm−2 in 1.0 mol dm−3 NaOH and 0.40 mol dm−3 CH3OH, and a high performance of 120 mA cm−2 was achieved in 1.0 mol dm−3 NaOH and 0.10 mol dm−3 C2H5OH. The oxidation current density reached 222 mA cm−2 in 0.1 mol dm−3 urea with the NaOH concentration of 8.0 mol dm−3 at around 0.48 V. The facile preparation method, high electrocatalytic activity, low cost and various applications make the NiO/NF be a promising electrode material.

The core-shell hierarchical mesoporous titanium dioxides with situ nitrogen dopen carbon and the stable architecture are synthesized by a feasible route, basing on the sol-gel, freeze-drying and calcination process. Nitrogen doped carbon is synergistically compounded with nano-TiO2 to fabricate the hybrid composite (C-N@MP-TiO2), which has high surface area of 318 m2 g−1 and large average pore size of 6.8 nm. This corresponding anode consisted of the hybrid composite exhibits superior specific capacity, rate capability, and long cycling stability. Also, the initial discharge capacity is up to 360 mAh g−1 at the current density of 0.1 A g−1 with the good capacity retention of 97% after 350 circles. The excellent rate performance presents the capacity of 173.6 mAh g−1 at the current density of 5 A g−1. Moreover, the large current reversible capacity (20 A g−1) can reach 172.2 mAh g−1 with long-term cycling stability over 500 cycles. Therefore, the superior electrochemical performances are attributed to the stable core-shell mesoporous structure and in-situ nitrogen doped carbon, which is not only improve the electron transport and lithium ion diffusion, but also facilitate the immersion of electrolyte.

A new approach for in-situ synthesis of crystalline Co–Fe–B nanoparticles was presented in which low temperature methods were developed by using metal chlorides and NaBH4 in an inorganic molten salt environment. Effects of different reaction systems/conditions on the phase formation, thermal behavior and microstructure were investigated. The melting point of reactants and impurities in final powders were reduced by the use of molten salt technique. After a reaction of CoCl2, FeCl3 and NaBH4 at 850 °C in sealed tubes, CoB and Fe3B phases formed separately. After a reaction under Ar flow; however, CoFeB2 solid solution nano powders were obtained in one step at 850 °C with an average size of 60 nm. After annealing at 1100 °C, stable and highly crystalline (CoFe)B2 solid solution phase with a Co:Fe molar ratio of 1:1 was achieved. As-synthesized particles exhibited ferromagnetic property, and possessed a narrow hysteresis curve characteristic of soft magnetic materials. Extended reaction temperature from 650 to 850 °C is seen to produce coercivity enhancement up to 500 Oe without significant reduction in saturation magnetization. On the other hand, after an annealing process and subsequent phase and chemical change, crystalline (CoFe)B2 particles exhibited superparamagnetic property.

Rare earth ions doped (oxy)nitride phosphors have been shown great potentials for the use as down-conversion luminescent materials in white light-emitting diodes (wLEDs). To realize super-high color rendering and high efficiency wLEDs driven by a 405 nm LED chip, a blue-green phosphor with high thermal stability and quantum efficiency is required. In this work, we reported an interesting blue-green emitting Li-α-sialon:Ce3+ (LimSi12-m-nAlm+nOnN16-n:Ce3+) that has a high external quantum efficiency of 53.5% and a small luminescence intensity reduction of 6.1% at 423 K. A variety of analytic techniques, such as X-ray diffraction (XRD), photoluminescence (PL) spectra, X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), and nuclear magnetic resonance (NMR) spectra, were used to clarify the relation between photoluminescent properties and local coordination environments. It showed that the emission color and luminescence intensity of Li-α-sialon:Ce3+ could be controlled by the microstructure tailoring. A warm wLED was demonstrated by pumping the phosphor with the blend of Li-α-sialon:Ce3+, β-sialon:Ce3+ and CaAlSiN3:Eu2+ by a 405 nm LED chip, which has the color temperature, color rendering index and luminous efficacy of 2390 K, 92.2 and 26.05 lm/W under a driven current of 20 mA. Our results indicate that Li-α-sialon:Ce3+ is a promising thermally robust blue-green phosphor for ultraviolet LED-driven wLEDs.

We investigated the interfacial reactions and mechanical reliabilities of different Ni layer thicknesses and P-containing Pd layers in thin electroless-Ni electroless-Pd immersion gold (thin-Au/Pd(P)/Ni(P)) surface-finished printed circuit board (PCBs) with Sn-3.0Ag-0.5Cu (SAC 305) solder joints. To analyze the optimal Ni layer thickness in the thin-Au/Pd(P)/Ni(P) for aging, we evaluated 0.3- to 1.0-μm Ni layers in thin-Au/Pd(P)/Ni(P) PCBs with SAC 305 solder joints aged at 75, 100, 125, and 150 °C for 1000 h. A scallop-type (Cu,Ni)6Sn5 intermetallic compound (IMC) dominantly formed at the bottom and top sides of the interfaces of all Ni joints under all aging conditions. Furthermore, a P-rich Ni layer formed at the interface between the (Cu,Ni)6Sn5 IMC and Cu substrate during aging regardless of Ni layer thickness. The (Cu,Ni)6Sn5 IMCs of the joints with 0.3- and 0.5-μm Ni layers aged at 125 and 150 °C for 1000 h were thicker than those of 0.7- and 1.0-μm Ni layers. In high-speed shear tests, the shear strength reduction rates of the joints with 0.3-μm Ni layer aged at 125 and 150 °C were higher than those of the 0.7- and 1.0-μm Ni layers. The brittle fracture rates of the joints with 0.3- and 0.5-μm Ni layers aged at 150 °C for 1000 h were higher than those of the 0.7- and 1.0-μm Ni layers. We determined that these trends arose from the diffusion barrier role of the relatively thick P-rich Ni layers maintained at the interfaces of the joints with 0.7- and 1.0-μm Ni layers for all aging temperatures and times. In low-speed shear tests, the shear strengths of the joints with 0.3-μm Ni layer were slightly lower than those of the 0.5- to 1.0-μm Ni layers. The low- and high-speed shear strengths of the joint with 0.7-μm Ni layer were similar to those of the 1.0-μm Ni layers for each condition. Therefore, Ni joint thicknesses of over 0.7 μm are expected to provide high reliability for aging.

This paper sets out the research into (Fe-Ga/Fe-Ni)n films in order to obtain a large piezomagnetic coefficients of 8.1 ppm/Oe and enhance magnetoelectric coupling at near zero bias field. The exchange coupling between Fe-Ga and Fe-Ni magnetic film makes the magnetoelectric (ME) coefficient of (8 nm Fe-Ga/8 nm Fe-Ni)30/AlN/Mo/Si reach 607 V/cm Oe, and the bias magnetic field is reduced to 4 Oe. Multilayer (8 nm Fe-Ga/8 nm Fe-Ni)30 films also have good soft magnetic properties, high piezomagnetic coefficients and low losses which can be used as a driving element for micro-sensor and micro-electro-mechanical system (MEMS).

In this study, three kinds of magnetic visible light photocatalysts (Fe3O4/GCN) were successfully prepared by a two-step method. The maximum magnetic property of the as-prepared composite was Fe3O4-op/GCN-3, with a maximum magnetization of 13.77 emu/g. Fe3O4/GCN exhibits excellent visible-light-driven photocatalytic activity for the degradation of organic pollutants. Among them, with regard to Fe3O4-ht/GCN-2, it was found that the degradation rate of MB is 2.37 times higher than that of GCN under visible light condition. On the one hand, one of the mechanisms for enhancing photocatalytic effect of composite material is the decrease of the band gap width. On the other hand, the generated photoelectrons can be transferred to Fe3O4 nanoparticles, which can effectively reduce the recombination of photogenerated electron-hole pairs. And the Fe3O4/GCN + visible light hybrid activation systems exhibited higher significant efficiency for organic pollutants degradation combined with PS. The maximum removal rate of MB, AB I, BP-5R,TC and BPA can reach 96.69%, 89.34%, 81.62%, 62.57% and 53.21%, respectively. This is mainly due to the hybrid activation system under visible light radiation can significantly accelerate the activation rate of S2O82−. The trapping experiment results investigations suggested that SO4•- and h+ are the main radical species in photocatalytic decomposition process. In addition, •OH species were then generated from the reduction of SO4•- by photo-electron.

Lithium-ion batteries are a typical representative of energy storage system with high storage capacity and good cycle stability. However, the low specific capacity can not meet the storage capacity requirements for new generation of electronic products, which have limited their practical application. Herein, CoF 2 nanoparticles loaded on carbon fiber cloth (CoF 2 @CFC) as a flexible composite material prepared without binder or conductive agent is introduced as a cathode for lithium-ion batteries, which exhibit a high specific capacity of 330 mA h g −1 at 100 mA g −1 and have a stable specific capacity of 100 mA h g −1 at 1 A g −1 even after 1000 cycles. In addition, the flexibility of CoF 2 @CFC creates an application potential in the field of flexible electronic devices and wearable electronics.

Control over the architecture, elemental distribution, composition and size of metal bimetallic nanocrystals can effectively manipulate and improve their catalytic performances. Herein, we construct the PdAg bimetallic nanostructures with Pd and Ag overlapped distribution to form an alloy feature via an easy operation method at ambient conditions. The prepared PdAg alloy nanocrystals are porous that composed of numerous branches on their surfaces with a composition of Pd100Ag0 to Pd61Ag39 and a size ranging from 16.4 ± 1.8 to 45.0 ± 1.5 nm. Impressively, after detail size- and composition-dependent electrocatalytic evaluations toward ethanol oxidation in alkaline, the Pd67Ag33 nanocrystals with a size of 27.0 ± 1.2 nm exhibit the highest mass activity (1394.49 mA mg−1), which is 4.77 and 5.46 times of porous Pd NCs and commercial Pd/C, respectively. Besides, the durability during electrocatalytic tests were also highly improved. The excellent electrocatalytic property is ascribed to the synergistic effect between Pd and Ag, the high surface area brought by the porous and branched morphology, as well as the proper size the alloy electrocatalysts provided.

CeO2 photocatalysts were successfully derived from Ce-MOFs, which were synthesized with dielectric barrier discharge (DBD) plasma method for the first time. The effects of solution concentration, discharge conditions and calcination conditions on the morphology, purity and photocatalysis of the products were investigated. The Ce-MOFs and CeO2 nanomaterials were characterized by XRD, SEM, TEM, EDS, UV–Vis, XPS, BET and ESR. CeO2 derived from Ce-MOFs synthesized under the conditions that discharge voltage of 5.2 kV, the Ce(NO3)3•6H2O and trimesic acid molar ratio of 1:1, and reactant concentration of 22 mol/L, at calcination temperature of 200 °C for 4 h showed the optimum photocatalytic performance, with 98% degradation rate of 50 mg/L methyl orange (MO) solution at 36 min. The high photocatalytic performance was attributed to the novel preparation method, high crystallization, wide range of UV-light absorption and strong adsorption capacity, as well as abundant oxygen vacancy defects. The methodology showed advantages for nano-structured catalysts with defects.

Al2O3-ZrO2 reticulated porous ceramics (RPCs) with hierarchical pore structures were prepared by vacuum infiltration. Al(OH)3 was applied to provide the pore structure. Vacuum infiltration using an alumina/aluminum hydroxide slurry via a pre-sintering cycle was performed to fill up the hollow struts generated due to burnout of the polyurethane foam template and the coating on the Al2O3-ZrO2 ceramic struts. The results showed that as the Al(OH)3 content in the infiltration slurry was increased from 5% to 13%, the pore size distribution of the ceramic struts widened and the major pore size decreased. In addition, a compressive residual stress developed within the multilayered struts because of the difference in thermal expansion of the Al(OH)3-Al2O3 coating layer and Al2O3-ZrO2 ceramic struts. Moreover, with increasing Al(OH)3 content in the infiltration slurry, the porosity of the ceramic struts gradually increased, resulting in a decrease in Young's modulus and thermal conductivity, which influenced the compressive residual stress and thermal stress within the ceramic struts. Furthermore, the potential of the fabricated RPCs as catalyst supports was demonstrated.

The development of new materials with hierarchical frameworks and tailored band structures is an attractive approach to efficiently photocatalytic hydrogen evolution. Here, we report a visible-light active calcium titanate (CaTiO3) photocatalyst with a hierarchical architecture constructed from single crystal nanowires, which was prepared by a one-pot hydrothermal reaction using polyvinyl alcohol (PVA) as structure directing agent. The hierarchical structure of the CaTiO3 samples involved single-crystal nanowires growing respectively along the [110], [1 1 ¯ 0] and [001] direction and intersecting each other perpendicularly which further featured a high specific surface area and oxygen vacancies. This material was able to split water into H2 under visible light irradiation. It was found that oxygen vacancies formed an impurity level at an energy level 0.95 eV below the conduction band acted as electron donors and promoted charge transport and separation.

Using Li metal-free anodes for lithium-ion oxygen and lithium-ion sulfur batteries is considered as a promising solution to resolve the hazard of Li metal anode. Although Si anode exhibits high capacity and low electrochemical potential, it cannot match with oxygen (or sulfur) cathode, because both lack cycleable lithium ions. In this work, a free-standing and fibrous Si/C anode is prepared by electrospinning and its simple but effective lithiation is proposed. When assembling the cells, the free-standing Si/C anode was put between mass-controlled lithium metal foil and separator, and then the Si/C anode could be lithiated after adding electrolytes. By optimizing a LiFSI based ether electrolyte, the Si/C anode could achieve good cycleablity comparable to that in carbonate electrolytes. The lithiated Si–O2 cells exhibit better cycling stability than the lithium oxygen cells with gel polymer electrolye. Moreover, because both Si anode and S@pPAN cathode are compatible with carbonate electrolytes, exceptional cycling performance has been achieved for the lithiated Si–S cells. This simple method could pave the way to commercial applications of lithium-ion oxygen and lithium-ion sulfur batteries.

The effects of Co doping on the phase stability, martensite transformation and magnetic properties of Ni 24- x Mn 17 In 7 Co x ( x = 0–5) ferromagnetic shape memory alloy were systematically investigated by the first-principles calculations. Co atom prefers to occupy the Ni sublattice. Co doping increases equilibrium lattice constant of austenite and decreases phase stability of austenite, 6 M and NM martensites. When 0 ≤ x x ≥ 2, the corresponding martensite transformation is PA→FA→NM. The martensitic transformation from austenite to martensite (6 M and NM) accompanies the ferromagnetic to ferrimagnetic transition in the Co content 0 ≤ x ≤ 2. However, the ferromagnetic state is popular in the whole martensitic transformation process for x > 2. The origin of magnetic properties and magnetostructure transformation were discussed based on electronic density of states.

When doped with transition-metal (TM) elements, modern commercial Ni-based superalloys achieve an extraordinary mechanical performance, including elastic behaviors and shear strength. By using density functional theory, the TM-element (3d:Sc–Zn, 4d:Y–Cd, 5d:Hf–Au) dependence of the elastic properties and the ideal shear strength of γ′-Ni3Al were determined. According to the positive definiteness requirement of the elastic stiffness coefficients matrix, we present the necessary and sufficient mechanical stability in terms of Born criteria for a monoclinic crystal system. By examining the mechanical stability and calculating the stress–strain curve at every single strain, the shear behavior of pure Ni3Al in the weakest shear-slip system was investigated in detail. Our results show that the d-orbital occupancy of TM elements can affect the mechanical properties of the γ′ phase significantly when they occupy the Al site in Ni3Al, where the elements toward the center part of each series (e.g. V, Cr, Mn, Nb, Mo, Ru, Ta, W, Re, and Os) can enhance the elastic constants, elastic moduli, and shear strength. Elements at the beginnings and ends of the series (such as Cu, Zn, Y, Ag, Cd, and Au) will decrease the elastic properties and shear strength of γ′-Ni3Al.

2D Tantalum disulphide (TaS2) has been widely studied as a typical transition metal dichalcogenides (TMDCs) with excellent optical, chemical and electrochemical properties. However, there is little research on the comprehensively characterizing the interaction between light and the 2D TaS2 material. In this work, we studied the nonlinear optical response of the high quality few-layer TaS2 nanosheets and its all-optical applications. Our research shows that 2D TaS2 nanosheet has a broadband characteristic and exhibits a strong Kerr nonlinear optical response based on the spatial self-phase modulation (SSPM). More importantly, by taking advantage of the highly nonlinear optical response of the2D TaS2, typical all-optical phenomena, such as all-optical switching and nonreciprocal light propagation, have been demonstrated experimentally. This work can be viewed as an important demonstration of a TMDCs-based application prototype in nonlinear photonics, which could potentially indicate an essential step toward miscellaneous TMDCs-based passive photonic devices (all-optical diodes, all-optical switches, etc.)

The development of well-ordered TiO2 nanotubes arrays (TNTAs) as a binder-free electrode in supercapacitors was hindered by their poor conductivity and low capacitance. Herein, the hierarchical structure of TNTAs/C/MnO2 (TNTCM) electrode was built via three-step process — typical anodization, carbon deposition and electrodeposition method. TiO2 nanotube arrays obtained from anodization provide a high surface area substrate for binder-free electrode, followed by carbon nanoparticles which could act as an electronic transfer medium penetrated into TNTAs using gas thermal penetration, the TNTAs/C electrode became high conductivity, then the two-dimension birnessite-type MnO2 nanoflakes were in situ growth onto TNTAs/C composites through scalable and easy electrodeposition method could storage energy by faradaic reaction. The resultant TNTCM hybrid composites manifest a remarkable specific areal capacitance of 492 mF/cm2, 207 times than that of TNTAs/C electrode, the value is comparable or much higher than those of previously reported TiO2 nanotubes-based electrode for supercapacitor. The synthesized TNTCM electrode exhibit a high energy density of 465 mWh/m2 at power density of 2.5 W/m2. In addition, the excellent energy storage performance is well maintained with a capacitance retention of 98% during 3000 charge–discharge cycles, indicating its promising application in energy storage and conversion fields.

This paper reports on the synthesis of ZnO/nitrogen-doped hierarchically porous carbon (ZnO/N–OHPC) and its application as electrode for supercapacitor. N–OHPC having large surface area, 3D ordered macropores and ordered mesopores in the carbon skeleton is fabricated from dual-templates with dicyandiamide as the nitrogen source. Through a convenient in situ solution growth way, ultrafine ZnO nanoparticles (∼3.2 nm) are evenly distributed on the macroporous walls of N–OHPC. The as-synthesized ZnO/N–OHPC (38.6 wt% ZnO) exhibits a maximum gravimetric capacitance of 720 F g−1 at 1 A g−1 within the potential window of 0.1–0.5 V. In addition, it exhibits a great rate ability (66% capacitance retention at 10 A g−1) and durability (90% of the initial capacitance was obtained after 30,000 cycles). The superior electrochemical performance is due to the synergistic effects of small ZnO nanoparticles and N-doped ordered hierarchically porous carbon.

The core-shell structured Ag2CO3@TiO2 composite was fabricated through a simple precipitation method by coating amorphous TiO2 on the Ag2CO3 surface. The morphologies, structure and optical property were characterized by field emission-scanning electron microscopy 3(SEM), high resolution-transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Ultraviolet–visible spectroscopy and photoluminescence spectra. The photocatalytic activity was investigated by the degradation of rhodamine B under visible light irradiation. Results show that the activity of Ag2CO3@TiO2 photocatalyst is much higher than that of pure Ag2CO3. It was revealed that the amorphous TiO2 shell layer effectively promotes the separation rate of photogenerated electron-hole pairs to inhibit the photocorrosion of Ag2CO3. Moreover, the core-shell structural Ag2CO3@TiO2 photocatalyst showed high photostability for the degradation of rhodamine B.

In order to replace the highly poisonous cyanide zincate process of Al alloy, an eco-friendly approach was developed, i.e., electrodeposition of Cu-Zn coating from ionic liquid/ethanol mixed bath. It was demonstrated that the Cu5Zn8 alloy produced from 1-ethyl-3-methylimidazolium trifluoromethylsulfonate (EMImTfO) and 20% (Volume percent) ethanol mixtures under optimal conditions showed cauliflower-shaped structure with a (330) preferred orientation, which could significantly improve the corrosion resistance of Al substrate in Watts bath, thereby elevating Ni coating quality. The overall property of Cu-Zn intermediate layer and its subsequent coating, including compactness, adhesive strength and corrosion resistance is approximately the same as that of cyanide zincate layer and its surface coating, suggesting that the new method is an ideal alternative to conventional zincate treatment.

The crystal and magnetic structures of Ce2CuGe6 compound were characterized by means of X-ray diffraction, neutron diffraction, magnetization, electrical resistivity, and magnetoresistance measurements. In this work, the crystal structure of Ce2CuGe6 was corrected to be orthorhombic Ce2(GaGe)7-type with Cmca space group based on the data of X-ray diffraction and neutron powder diffraction experiments. The results obtained in magnetic measurements and neutron powder diffraction suggest that Ce3+ (2F5/2) is the only magnetic species in the compound. Below its Neel temperature TN = 14.47(8) K, the Ce moments order in the structure composed of ferromagnetic bi-layers alternately stacking along the c-axis and the easy axis is along the crystallographic b-axis. The neutron diffraction results could explain the field-induced ferromagnetic component along c-axis below TN, and a spin-flip transition at the critical field Hc ∼12 kOe along b-axis. Ce2CuGe6 exhibits metallic electrical transport between 2 and 300 K. The magnetic scattering among the crystalline electric field (CEF) of the rare earth ions in the paramagnetic state dominates the low-temperature electrical transport behavior. Besides, the metamagnetic transition is also evidenced as a discontinuous jump in the magnetoresistance.

Understanding how minor actinides affect the synroc stability is very important for waste management. After a careful review of literature, however, existing reports did not reach a satisfactory level on the effect of minor actinides on monazite structural properties. In this study, the electronic properties, structures, defect formation energies and excess properties of Am-doped LnPO4 (Ln = La, Ce, Nd, Sm, Eu, Gd) monazites were investigated by first principles calculations. The calculation results indicate that the inner shell Am-5f orbital can participate in chemical bonding with O-2p orbital in all considered monazites. By analyzing their structures, we find the lengths of Am–O bond in Ln-monazite from La to Gd are gradually shortened, resulting in the shrinkage of [AmO9] polyhedron along the lanthanides, which is different from the evolution of their lattice parameters. This shrinkage plays an important role in the Am defect stability. For instance, the calculated vacancy defect formation energy reveals that the Am has a stronger binding energy in Gd-monazite, making it more difficult to form a vacancy defect. Moreover, after analyzing the thermodynamic excess properties, we find that Am-doped NdPO4 monazite has the highest thermodynamic stability, and all the Ln1-xAmxPO4 solid solutions can remain phase stable above 285 K.

The deformation activities near crack tips of submicron-sized single-crystalline Mo were investigated using in situ transmission electron microscopy (TEM) with mixed mode I-II loading. Results show that dislocations in multiple slip systems were activated in front of crack tips. These dislocations glided on the uncommon slip planes of {123}, forming dislocation arrays. These dislocations moved at velocities of 3–5 nm/s with spacing of ∼10–34 nm in the zone of ∼50–300 nm away from crack tips. Dislocation velocity and spacing were influenced by the force from elastic crack stress field. Additionally, phase transformation from body-centered cubic to face-centered cubic was also activated in front of crack tips, and high densities of interface dislocations were observed at the semicoherent phase interfaces. Two kinds of phase transformation mechanisms were uncovered. One is the Pitsch mechanism, which is rarely accessed, while the other is the Nishiyama-Wasserman/Kurdjumov-Sachs mechanism.

Zn content has significant influence on the hot workability and final properties of Al–Zn–Mg–Cu alloys. In the present work, single and double stage hot compression tests have been performed on Al–Zn–Mg–Cu alloys with various Zn contents at temperatures of 300 °C and 400 °C, and strain rates of 0.01 s−1 and 0.1 s−1, respectively. The results showed that the static softening curve plateau was observed, both the duration of static softening plateau and softening fraction decreased with increasing Zn content at deformation temperature of 300 °C. When deformation temperature increased to 400 °C, the static softening curves appeared approximate typical sigmoidal shape with slight influence from Zn content. By combining additional in-situ electrical resistivity measurement, hardness testing and microstructural observations, the static softening mechanisms were found to be the functions of static recovery and precipitates coarsening at lower temperature, and static recovery and static recrystallization at higher temperature. The increased Zn addition mainly affected static softening mechanisms at 300 °C by forming precipitates. The simplified static softening kinetics were also investigated based on Johnson-Mehl-Avrami-Kolmogorov model which coupling static recovery and static recrystallization.

Transition oxides are a kind of promising anode materials for lithium-ion batteries due to their high capacity and low cost. However, it is a great challenge to realize high power density and long cycle life. Size control and surface coating are effective ways to increase reaction sites and improve electrical conductivity. In this work, rice crust-like structure of thin carbon layer coated Fe3O4 nanoparticles (∼15 nm) uniformly covering rGO sheets (Fe3O4@C/rGO) is achieved. This composite delivers a high capacity of 594 mAh g−1 even after 1000 cycles at a high current rate of 5.0 A g−1, which can be attributed to the high surface pseudocapacitance dominated storage mechanism. Further analysis reveals that the high extrinsic pseudocapacitance is closed to the nanosized structure and carbon coating, because large surface area and good electrical conductivity are essential for the improvement of extrinsic pseudocapacitance. This work offers a new perspective for future structure design for high-rate and long-life anode materials of lithium-ion batteries.

Designing low-cost and highly efficient electrocatalysts has become a critical aspect to achieve sustainable energy production. Herein, we report the preparation strategy of MoS2 on Co-oxide nanoparticles embedded nitrogen-doped carbon nanosheets (Co-NC) those derived by ZIF-L anchored on a carbon cloth as an electrode for hydrogen evolution reaction (HER). The hybrid electrode denoted as MoS2/Co-NC/CC was synthesized in sequence of the growth of the leaf-like zeolitic imidazolate framework (Co-ZIF-L) on a carbon cloth (CC), the carbonization of the Co-ZIF-L and deposition of MoS2 by metal organic chemical deposition (MOCVD). The hierarchical porous catalyst presented remarkable electrochemical activity towards the HER in acidic solution, exhibiting great stability and fast kinetics with a small Tafel slope of 51 mV dec−1. Moreover, to produce a current density of 10 mA cm−2 (η10), MoS2/Co-NC/CC required a low overpotential of 111 mV, which is comparable with Pt.

We compute the temperature dependent relaxation time (τ) of charge carriers in LiScX (X = C, Si, Ge) half-Heusler (hH) alloys using the deformation potential theory. This temperature dependent τ of charge carriers is used to investigate its effect on the thermoelectric properties of these hH alloys. It is shown that there is a significant effect of temperature dependent τ of charge carriers on the thermoelectric properties of these hH alloys.

Control of Eu valence is one of the main issues to obtain mixed−valent Eu2+/3+ co−doped phosphor with flexible−tunable emission spectra. In this study, for the first time, we report a simple single cation substitution strategy for controlling Eu valence. The structure of Sr1−xBaxAl2Si2O8 host was tailored by Ba2+ substitution for Sr2+ ions. The lattice parameters show a linear evolution with increase in Ba2+ amount. Correspondingly, the Eu3+ emission intensity also increases over Ba2+ amount. The spectral variation was considered to be attributed to the suppression of Eu3+ reduction by the lattice stress, which is introduced by ion substitution. Finally, valence control of Eu and spectral tuning of Eu3+/2+ co−doped Sr1−xBaxAl2Si2O8 phosphor were realized by the proposed strategy. This study will open a novel avenue for Eu valence control and spectral tuning of mixed–valent Eu doped phosphors.

By using nanoindentation techniques combined with atomic force microscopy, a pronounced creep behavior at ambient temperature as demonstrated by small creeping stress exponents was observed in (Co0·7Fe0.3)0.68B0·219Si0·051Nb0.05 metallic glass with 0.5 at.% Cu addition. Such obvious creep deformation is due to the precipitation of Co(Fe)-rich clusters induced by the chemical effect of Cu. It promotes the formation of the weakly bonded structure and thereby the generation of plenty of excess free volume during the nucleation and propagation of multiple shear bands in the process of deformation, which contributes to a steady creep behavior and large plasticity. Our work provides a microscopic understanding of creep behaviors in Cu-doped metallic glasses, which might also guide for improving the plasticity of these alloys.