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We used selective laser melting (SLM) to produce a three-dimensional specimen of pure Ti and found that an equiaxed grain structure and weak crystallographic texture could be achieved simultaneously via subsequent heat treatment. These traits have never been attained simultaneously in pure Ti prepared by traditional methods such as casting and rolling. This remarkable achievement was possible because recrystallization occurred during heat treatment without plastic deformation; such deformation introduces stored energy that drives recrystallization but inevitably causes a strong texture to develop. The occurrence of recrystallization was attributed to unique features of the SLM process including a very high cooling rate and repetitive layer stacking. These features generated considerable stored energy by affecting solidification and the β → α phase transformation. Steep in-grain orientation gradients and a fine lath structure also contributed to the activation of recrystallization by facilitating recrystallization nucleation. The heat-treated specimen showed tensile properties with significantly reduced anisotropy. This finding will provide new strategies for developing isotropic metallic materials and may introduce new applications of SLM. • A three-dimensional specimen of pure Ti was produced using selective laser melting. • Both equiaxed structure and weak texture were achieved by subsequent heat treatment. • These traits cannot be attained simultaneously by traditional manufacturing methods. • This desirable ability of SLM originates from unique features of SLM process. • The heat-treated sample had significantly reduced anisotropy in tensile properties. [ABSTRACT FROM AUTHOR]

Abstract Bimodal grain structures are often produced in a metal by employing severe plastic deformation followed by low-homologous-temperature annealing (≤0.4 T m , where T m is melting temperature). Here, a bimodal grain structure was achieved in a Co–20Cr–15W–10Ni–C superalloy via moderate cold rolling (strain ≈0.3) and ultrahigh-homologous-temperature annealing (≥0.8 T m). During annealing, carbide-assisted heterogeneous static-recrystallization played a key role in forming the bimodal grain structure. A 40% increase in combined strength and ductility was observed. Graphical abstract Image 1 Highlights • A bimodal grain structure was achieved in a superalloy without severe deformation. • Cold rolling and ultrahigh-homologous-temperature annealing were carried out. • Carbide-assisted heterogeneous static recrystallization occurred during annealing. • The bimodal grain structure provided 40% higher σ × ε values than uniform grains. [ABSTRACT FROM AUTHOR]

Abstract Four morphology-dependent ZnCo 2 O 4 nanoarchitectures on Ni-foam with the aid of auxiliary reagent ammonium fluoride (NH 4 F) were facilely synthesized via a simple hydrothermal method and a consequent annealing process. With the gradual increase of NH 4 F, there was a morphological transformation from nanoflake, through nanowire@nanoflake and hetero-nanowire, to hierarchical leaf-like. The BET surface area and the specific capacitance at 1 A g−1 were both gradually improved, from 63.9 to 89.3 m2 g−1 and from 600 to 1700 F g−1, respectively, during the process of morphological change. The hierarchical leaf-like ZnCo 2 O 4 had the lowest charge transfer resistance and the highest capacitive behavior, as well as considerable cycling performance (110% after 8000 cycles at 2 A g−1). A full button cell combining both anode material (AC) and cathode material (leaf-like ZnCo 2 O 4) displayed satisfying energy density (63 Wh kg−1) and power density (795.5 W kg−1) as well as firm cycling performance (98% retention after 4000 cycles). The successful illumination of LEDs by the constructed full cell implied the promising practicability for future industrial green energy-storage devices usage of the ZnCo 2 O 4 nanomaterials. Graphical abstract Image 1 Highlights • Four ZnCo 2 O 4 nanostructures on Ni foam with disparate morphologies are fabricated. • Among the four electrodes, the leaf-like ZnCo 2 O 4 exerts the highest specific capacitance, excellent cycling ability. • A full cell device based on AC anode and the leaf-like ZnCo 2 O 4 cathode has been successfully fabricated. • The full cell device delivers a high energy density of 63 Wh kg−1 at the power density of 795.5 W kg−1 [ABSTRACT FROM AUTHOR]

Mg 2 TiO 4 ceramics were prepared with MgO and TiO 2 by high energy ball milling method. Highly reactive nanosized Mg 2 TiO 4 powders were successfully synthesized at 1000 °C in oxygen atmosphere for milled 30 h, about 200 °C lower than that by a conventional solid-state reaction process. The pure Mg 2 TiO 4 nanopowders average particle size were reduced to about 163 nm. Mg 2 TiO 4 ceramics at 1175 °C had the excellent microwave dielectric properties ɛ γ = 13.9, Q × f = 98,600 GHz, τ f = −50.9 ppm/°C. [ABSTRACT FROM AUTHOR]

Highlights: [•] The AWO4 nanopowders with a single phase were synthesized by HEBM for 30min. [•] The average particle size of the milled powders is reduced to 120–180nm for 30h. [•] AWO4 ceramics were well sintered at relatively low temperatures of 900–1000°C. [•] Samples have dense microstructures and excellent microwave dielectric properties. [ABSTRACT FROM AUTHOR]

Laser-powder bed fusion (L -PBF) is being increasingly employed in the fabrication of commercially pure titanium (CP-Ti) components for biomedical applications. However, L -PBF-manufactured CP-Ti parts typically exhibit high strength and reduced ductility owing to the formation of acicular α′ martensite. It is essential to decompose the acicular α′ martensite into the equilibrium α phase through post-heat treatments to achieve superior mechanical properties. In this study, post-heat treatments were applied to L -PBF-fabricated CP-Ti Gr. 1−Gr. 4 samples. The microstructures of the as-fabricated CP-Ti samples were dominated by acicular α′ martensite, which exhibited high strength (>800 MPa) but low ductility (<20%). Full annealing resulted in the formation of equiaxed grains and the disappearance of the columnar structures in the CP-Ti samples. The equiaxed grains contributed to high ductility (>30%) in the Gr. 1 and Gr. 2 samples, but low ductility (<20%) in the Gr. 3 and Gr. 4 samples. This low ductility is associated with the formation of grain-boundary β layers. Well-designed partial annealing led to the formation of bimodal structures consisting of both equiaxed and fine lamellar grains. This specific structure provides both a high strength (>700 MPa for Gr. 2 and,>850 MPa for Gr. 4) and high ductility (>35% for Gr. 2 and Gr. 4), which are superior to those of the samples processed under full annealing conditions. Therefore, tailoring the bimodal structure in the L -PBF-manufactured CP-Ti for both high strength and ductility is promising for biomedical applications. • Bulk CP-Ti Gr. 1−Gr. 4 were produced using selective laser melting. • As-fabricated CP-Ti exhibited high strength and low ductility. • Equiaxed and bimodal structure were achieved by post-heat treatment. • The bimodal structures provided higher σ × ε values than equiaxed grains. [ABSTRACT FROM AUTHOR]

• Novel Z-scheme Bi 2 WO 6 /Ni-MOF heterojunction was prepared. • Bi 2 WO 6 were evenly covered on the outside of 2D Ni-MOF with intimate interface. • Formed Z-scheme structure facilitated the separation of photoexcited charges. • The heterojunction exhibited enhanced photocatalytic activity for MB degradation. • The mechanism for photocatalytic degradation of MB was proposed. [Display omitted] Constructing Z-scheme heterojunction is considered to be a promising strategy to isolate photogenerated carriers and boost the activity of the photocatalysts. Here in, a novel Z-scheme Bi 2 WO 6 /Ni-MOF heterojunction with intimate interface was constructed via wrapping flowerlike Bi 2 WO 6 on 2D Ni-MOF sheets. The resultant Bi 2 WO 6 /Ni-MOF heterojunction displayed superior photocatalytic performance with respect to methylene blue degradation under visible light illumination. When the content of Ni-MOF was 20 wt%, the Bi 2 WO 6 /Ni-MOF heterojunction achieved the highest activity, which was 24.0 and 6.4 folds that of the pristine Ni-MOF and Bi 2 WO 6 , respectively. The superior degradation performance was caused by the formation of a direct Z-scheme heterostructure between Ni-MOF and Bi 2 WO 6 , which boosted the separation of photoinduced carriers. The principal active species and possible photocatalytic mechanism were also explored. This study provides a pathway to design and fabricate efficient Z-scheme photocatalysts for environmental remediation. [ABSTRACT FROM AUTHOR]

• The thickness-dependent thermoelectric transporting is studied for few-layered SnSe with thickness from 1 L to 4 L. • The relaxation time and the carrier mobility are derived by extensive calculations using EPW. • As the thickness increases, the carrier mobility increases while the thermal conductivity decreases. • The thermoelectric performance is significantly enhanced as the thickness increases from 1 L to 4 L. • Bulk SnSe of n-type has larger figure of merit along the out-of-plane direction than the in-plane directions. Recently, SnSe of orthorhombic phase has attracted much attention due to its excellent performance in thermoelectricity, yet the thickness-dependent thermoelectric properties were poorly studied. We have investigated the thermoelectric transporting properties of few-layered (from 1 L to 4 L) and bulk SnSe by using density functional theory plus Boltzmann transport theory. We employed the electron-phonon Wannier method to obtain the accurate transporting parameters, i.e., carrier mobility as well as relaxation time, in contrast to those derived from deformation potential theory. Our results reveal that the band gap decreases from 0.91 eV (1 L) to 0.59 eV (bulk) as the thickness increases, and meanwhile the effective charge mass increases slightly. As bulk SnSe is thinned to the monolayer, the high frequency modes are stiffened while the low frequency modes are softened, and meanwhile the acoustic velocities become larger. At 300 K, the thermal conductivity of bulk SnSe takes 1.52, 0.80 and 0.41 W m−1 K−1 for κ a , κ b and κ c respectively, in good agreement with the experimental values. Thermal conductivity of few-layered SnSe decreases slightly from 2.45 to 1.61 W m−1 K−1 for κ a , and from 1.81 to 1.02 W m−1 K−1 for κ b as the layer number increases from 1 L to 4 L. The EPW calculations reveal that the electron mobility of n -type films increases rapidly from 24.4 cm2/V s (1 L) to 179.6 cm2/V s (4 L) and the hole mobility of p -type films increases from 47.2 cm2/V s (1 L) to 1211.1 cm2/V s (4 L) at 300 K as the thickness increases. Compared with the monolayer, thicker film of SnSe has larger carrier mobility as well as lower thermal conductivity, which leads to better thermoelectric performance. At 700 K, the figure of merit is enhanced from 0.22 (1 L) to 0.58 (4 L) for n -type films in electron density of −0.55 × 1013/cm2. Our research casts some light on the future thermoelectric applications based on few-layered SnSe. [ABSTRACT FROM AUTHOR]

Abstract: A study on the microstructural characteristics and tensile properties of a new high strength Ti–6Cr–5Mo–5V–4Al alloy were investigated. Both the α/β and β solution treatment and subsequent aging at temperatures ranging from 460°C to 560°C were introduced to investigate the microstructural characteristics and microstructure–property relationships. The results show that the primary α phase formed during the α/β solution treatment can increase the stability of the β matrix and then restrain the size of secondary α phase during subsequent aging. In the α/β solution plus aging condition, the secondary α phase with the size of about 1μm results in a high strength above 1500MPa with −6% of elongation. The β solution treatment leads to the least stable β matrix and the greatest driving force for secondary α phase, so coarser α phases tend to form during aging. The β solution plus aging does not lead to attractive high strength because of the coarser and non-uniform α phase. And it also leads to a poorer combination of strength and ductility than the α/β solution plus aging. Direct aging exhibits the best strengthening. The ultimate strength of the alloy is about 1600MPa with acceptable elongations of 6.5–7.5% when direct aged at 500°C for 2–8h. It benefits from the mixed microstructure with nano-scale and micron-scale α phases. However, more detailed investigations are needed to improve the ductility. As a whole, the alloy can be heat treatable to obtain an excellent balance of strength and ductility, and provide abundant stress levels with optional ductility (900–1600MPa in ultimate strength and 6–20% in elongation). [Copyright &y& Elsevier]

Abstract: Mg2SiO4 nanopowders were prepared from MgO and SiO2 mixtures by using a high energy ball milling method, combined with subsequent calcination at low temperatures. After milling for 30h, pure phase Mg2SiO4 nanopowders with an average grain size of 147.4nm were obtained at 850°C, 300°C lower than that required by a conventional solid state reaction process. Mg2SiO4 ceramics sintered at a low temperature of 1075°C showed almost full density and excellent microwave dielectric properties (ɛ r =7.2, Q × f =193,800GHz, τ f =−58ppm/°C). [Copyright &y& Elsevier]

• 2D/2D heterojunction of ultrathin NiMOF/Ti 3 C 2 nanosheets was fabricated. • Ti 3 C 2 as a cocatalyst promoted the separation of photogenerated charge carriers. • The hybrids exhibited enhanced photocatalytic activity for MB degradation. • The mechanism for photocatalytic degradation of MB was proposed. ga1 Two-dimensional (2D) nanomaterials, especially 2D ultrathin layered nanomaterials, have been under increasing demand for solar energy usage and conversion owing to their unique characteristics such as large surface area, easily accessible catalytic sites and high electron transfer efficiency. In this work, layered Ti 3 C 2 was used as the noble-metal-free cocatalyst to design 2D/2D composite by a simple electrostatic self-assembly process, which was based on the ultrathin nickel metal organic framework (UNiMOF) nanosheets. Thanks to the similar layered structures, a conductive and intimate interface formed between Ti 3 C 2 and UNiMOF, which could promote the charge transfer and accelerate the separation of photoexcited electrons and holes. Thus, the obtained 2D/2D UNiMOF/Ti 3 C 2 hybrids exhibited higher activity for photocatalytic degradation of methylene blue (MB) than bare UNiMOF under UV–vis light irradiation, and the activity was boosted by almost 4.0 times when loaded with 1.5 wt% Ti 3 C 2. Moreover, the as-synthesized UNiMOF/Ti 3 C 2 composites showed excellent stability. The possible mechanism for photocatalytic degradation of MB was also explored. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs), have been widely applied as templates/precursors to synthesize porous materials for various applications. However, the MOF-derived solid solutions were scarcely reported. In this work, uniform monodisperse Cd 0.5 Zn 0.5 S nanospheres were fabricated via a facile solvothermal route using Cd–Zn–Fe Prussian blue analogs (Cd–Zn–Fe PBA) as the precursor. Compared with the Cd 0.5 Zn 0.5 S nanoparticles prepared by the conventional method, the Cd 0.5 Zn 0.5 S nanospheres exhibited higher specific surface area, better charge transfer rate and stronger light absorption capacity, which led to higher photocatalytic activity. The H 2 evolution rate of the resultant Cd 0.5 Zn 0.5 S nanospheres was 4341.6 μmol h−1 g−1 under visible light irradiation, with a quantum efficiency of 4.5% at 420 nm. Besides, the Cd 0.5 Zn 0.5 S nanospheres also exhibited good stability during the photocatalytic reactions. The present work provides an idea for the preparation of uniform-sized solid solutions using MOFs as templates. Image 1 • Uniform monodisperse Cd 0.5 Zn 0.5 S nanospheres were prepared by a MOF-derived method. • The obtained Cd 0.5 Zn 0.5 S nanospheres exhibited excellent photocatalytic activity. • A H 2 -evolution rate of 4341.6 μmol h−1 g−1 (QE of 4.5% at 420 nm) was obtained. • The Cd 0.5 Zn 0.5 S nanospheres also exhibited good stability. [ABSTRACT FROM AUTHOR]

Bimetal oxides have superior supercapacitive properties because of synergistic effect, but their applications are usually limited because of low conductivity. Metal cations doping has been a promising method to break the restriction. Here, we first selected CuCo 2 O 4 nanowire arrays with high electrochemical activity as mother bimetal oxides and Al3+ with high electric conductivity as the dopant to investigate the influence of doped amounts on the electrochemical behaviors. With the increase of doped Al3+, the specific capacitance increased at first and then decreased, in accord with the analysis results of the conductivity, capacitive and diffusion-controlled contribution. The sample with the optimal doping amount had the highest capacitive behavior (1871 F g−1 at 1 A g−1) and considerable cycling performance (93% after 8000 cycles at 2 A g−1). A full button cell consisting of anode material (AC) and cathode material (the optimal Al-doping CuCo 2 O 4) exhibited satisfied energy density (65 Wh kg−1) and power density (735 W kg−1) as well as favorable cycling performance (95% retention after 4000 cycles). A LED was successfully powered by the constructed full cell suggested the promising application in future industrial green energy-storage devices of the Al-doping CuCo 2 O 4 nanomaterials. Image 1 • Al3+ was doped into CuCo 2 O 4 nanowires to investigate the influence of doped amounts on the electrochemical behaviors. • With the increase of doped Al3+, the specific capacitance increased at first and then decreased. • A full cell device based on AC anode and the optimal Al-doping CuCo 2 O 4 cathode has been constructed. • The full cell device exhibited a high energy density of 65 Wh kg-1 at the power density of 735 W kg-1. [ABSTRACT FROM AUTHOR]

The impacts of various tensile strains on both DC and RF performance of AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) on a silicon-on-insulator (SOI) substrate were investigated using pulsed-IV and pulsed-S-parameter tests. The sensitivity of MIS-HEMTs to various tensile strains was observed via pulse measurements because of the improved self-heating effect. The DC and RF performance of MIS-HEMTs on a SOI substrate were found to be enhanced with the pulse width decreasing under small tensile strain. A significant hot phonon effect was observed for MIS-HEMTs under larger tensile strain, particularly for shorter pulse widths. Additionally, an obvious reduction of f max was observed under larger tensile strain because the channel resistance increased via the hot phonon effect, despite the increase in f t. The results indicated that tensile strain in the ultra-thin thinned substrate of AlGaN/GaN HEMTs should be carefully monitored in compact packages for high-power and high-frequency applications. • GaN MIS-HEMTs on SOI under external mechanical tensile strain were studied. • DC and RF characteristics of GaN MIS-HEMTs were investigated using pulse measurement. • Hot phonon effect was observed for larger tensile strain device at shorter pulse width. • Tensile strain on thinner substrates should be considered in GaN-based RF power devices. [ABSTRACT FROM AUTHOR]

Type II heterojunction photocatalysts possessed excellent redox properties and had great potential for environmental remediation applications. In this paper, a novel Bi source of Bi-MOF was created by using NaBiO 3. Additionally, KCl was incorporated to contest Bi-MOF for the Bi source, with the objective of generating floral BiOCl. Subsequently, heterostructures based on metal-organic skeletons (MOFs) were constructed with Bi-MOF and BiOCl, with the aim of exposing the (002) crystal faces of BiBDC. The modification of the (002) crystal surface was employed to create holes or generate more photogenerated electrons, resulting in efficient degradation of rhodamine B (RhB) and simultaneous reduction of hexavalent chromium. The heterogeneous structure demonstrated a degradation rate of 97 % for rhodamine B (RhB) after reaching adsorption equilibrium in 30 min of dark reaction and 10 min of visible light irradiation. Furthermore, the reduction rate of hexavalent chromium (Cr (VI)) was 95.5 % after reaching adsorption equilibrium in 30 min of dark reaction and 70 min of visible light irradiation. The results of the cycling experiments demonstrated that both 1:1 BBOC and 1:3 BBOC retained their structural integrity following four cycles. The active species trapping results indicated that the hole radicals (h+) and electrons were responsible for the degradation of RhB and the reduction of hexavalent chromium, respectively. This study also revealed the degradation pathways and mechanisms of heterojunctions, providing new ideas for the preparation of photocatalysts for environmental remediation. [Display omitted] • Photocatalytic activity of (002) crystalline facets for novel Bi-sourced Bi-MOF nanoparticles enhanced. • The catalysts in question are multifunctional and are capable of photocatalytic degradation of RhB and reduction of Cr(IV). • The special structure improves the efficiency of rhodamine B degradation and Cr(IV) reduction. [ABSTRACT FROM AUTHOR]

Nickel-based enzymeless glucose sensors have been extensively explored. However, poor conductivity and severe aggregation of nickel-base nanocomposites often reduce the performance of its practical applications. Herein, free-standing TiO 2 /C core-shell nanofiber arrays (TiO 2 /C NFAs) were fabricated directly on a titanium foil to serve as the one-dimensional (1D) conductive substrate. Nickel-cobalt binary nanoparticles were then deposited on the nanofibers to form the NiCo/TiO 2 /C NFAs for enzymeless glucose sensing. The NiCo/TiO 2 /C NFAs exhibit much improved sensitivity and excellent stability towards glucose determination, with a wide linear range from 1 μM to 7658 μM, and a high sensitivity of 975.3 μA mM−1 cm−2. The detection limit is calculated to be 0.6 μM (S/N = 3). The NiCo/TiO 2 /C NFAs also show excellent selectivity with minimal interference from the coexistent species. The superior analytical performance should be attributed to the large specific surface area of the 1D nanostructure, direct electron transfer pathway via the free standing TiO 2 /C NFAs, and high activity of the binary Ni–Co electrocatalyst. Image 1 • Free standing enzymeless sensor was fabricated with Nickel–Cobalt binary catalyst. • Core-shell TiO 2 /C nanofiber arrays serve as the substrate to load the catalyst. • The sensor exhibits high sensitivity and selectivity toward glucose determination. [ABSTRACT FROM AUTHOR]

Nickel-cobalt layered double hydroxides (LDHs) as electrode materials have recently received intense interests. However, the low conductivity, sluggish charge transfer kinetics and poor electrolyte penetration restrict the capacitive performance and hinder their practical applications. Herein, the Ni-Co-LDH nanosheets were introduced to the core/shell structured TiO 2 /C nanofiber arrays (TiO 2 /C NFAs) to construct a free-standing composite electrode for supercapacitor through a one-step electrodeposition method. The best-performing Ni 1 Co 1 -LDH/TiO 2 /C NFAs electrode exhibits high specific capacitance (1717.8 F g−1 at 1 mA cm−2), remarkable rate capability with 75.1 % retention when the current density increased from 1 mA cm−2 to 75 mA cm−2, and excellent cycling stability (84.1 % of the original capacitance after 5000 cycles at 78.1 A g−1), surpassing most of the Ni-Co-LDH electrodes reported before. This excellent performance owes to the high conductivity of TiO 2 /C NFAs which can endow the low ohmic resistance and high diffusion coefficient of Ni-Co-LDH which may alleviate the structure degradation. Meanwhile, the Ni-Co-LDH with the optimized Ni/Co ratio of 1:1 can provide proper particle size of LDH nanosheets, small charge transfer resistance (R ct), and high stability of Ni-Co-LDH to resist the structure degradation in the long-term cycling process. [Display omitted] • NiCo-LDH/TiO 2 /C NFAs developed as the free standing electrode for supercapacitor for the first time. • NiCo-LDH/TiO 2 /C NFAs possess high specific capacitance. • NiCo-LDH/TiO 2 /C NFAs deliver excellent stability after long charge-discharge cycles under a high current density. [ABSTRACT FROM AUTHOR]

The oxidation behaviors of Fe-3.0 wt%Si non-oriented electrical steel were studied in the high-purity Ar, compressed dry air, Ar-H 2 O mixed, and Air-H 2 O mixed atmosphere when annealed at 1200 °C for 200 min. The oxide layers generation and transformation mechanism of electrical steel during the high-temperature annealed process was characterized and discussed systematically by means of the XRD, SEM, EDS, and XPS analysis methods. Under compressed air conditions, only O 2 participates in the oxidation reaction. And the oxide layer has a typical three-layer structure. The oxidized particle layer only could be observed in the H 2 O-containing atmosphere, and the particle size and morphology of the oxide layer present an obviously evolution process. During the oxidation reactive process between Fe, Si and O, H 2 O and O 2 could play a synergistic effect. In addition, this synergistic effect leads to the cross-wrap structure appearing between the oxidized particle layer and the outermost oxide layer. The oxide layer thickness increases significantly in the Air-H 2 O atmosphere because of above conditions. This research lays the groundwork for a more in-depth investigation of silicon steel oxidation behavior. • Annealed with the hybrid atmosphere was applied to study the oxidation mechanism of Fe-3.0 wt%Si electrical steel. • The synergistic effect of H 2 O and O 2 leads to the cross-wrap structure appearing between the oxidized particle layer and the outermost oxide layer. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide monolayers have shown enormous potential in thermoelectric application in recent years. We now focus on the thermoelectric properties of WS 2 -WSe 2 nanoribbons with superlattice (SL) and Janus (JA) structures using first-principles calculations. The WS 2 , WSe 2 , SL, and JA nanoribbons with the ribbon width from 5 to 7 have high structural stabilities. All nanoribbon electronic structures are semiconductors and the ribbon width will modify bandgaps. It can be also observed that WS 2 , SL, and JA nanoribbons with a ribbon width of 5 have the largest carrier mobilities (up to ~500–1400 cm2 V−1 s−1) and relaxation times (up to ~400–600 fs). We further calculate the electronic transport coefficients and discover that the SL and JA nanoribbons with a ribbon width of 5 exhibit the largest power factors as high as ~80 mW m−1 K−2. Afterwards, the minimum lattice thermal conductivities of SL and JA nanoribbons are 0.53 W m−1 K−1 and 0.61 W m−1 K−1, which are suppressed owing to the declining phonon group velocity and phonon lifetime. The maximum ZT values of SL and JA nanoribbons can reach 5.47 and 4.13. This investigation provides a solid evidence for the application of WS 2 -WSe 2 nanoribbons as promising thermoelectric materials. [Display omitted] • All WS 2 -WSe 2 nanoribbons have stable state and semiconducting properties. • Superlattice and Janus nanoribbons have large carrier mobilities. • The smallest k ph of superlattice and Janus nanoribbons are 0.53 and 0.61 W m−1 K−1. • The high ZT of 5.47 and 4.13 for superlattice and Janus nanoribbons are obtained. [ABSTRACT FROM AUTHOR]

Zinc ion batteries (ZIBs) are newly emerging and widely attracted energy storage devices owing to its advantages of intrinsic safety and low-cost effectiveness. Herein, we reported a nanorod-like MnO 2 cathode material composited with carbon and pyrrolic nitrogen by in-situ co-precipitation method at room temperature, which was used as ZIB cathode to deliver a high specific capacity of 339 mAh g−1 at 100 mA g−1 and a long cycle stability over 2000 cycles at 1000 mA g−1, resulting in the ultrahigh coulombic efficiencies approximate to 100%. The improved performance was attributed to the enhancement of structural stability and more zinc ion insertion sites after introducing the 2-methylimidazole (2-MI) coating layer. The phase transition of α-MnO 2 @2-methylimidazole (α-MnO 2 @2-MI) and the formation of more porous architecture could be the origin of the continuous capacity increasing in the initial several cycles, which was proved by the results of the ex-situ x-ray diffraction (XRD) and the scanning electronic microscope (SEM). This method can be a more realistic choice for the further commercial applications of low-cost and easily-accessed ZIBs with excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

Abstract: Ternary compound Ti3AlC2 was synthesized through pulse discharge sintering (PDS) the powder mixture of TiH2/Al/C without preliminary dehydrogenation. The synthesis mechanism of Ti3AlC2 was revealed to be completed via the reactions among the intermediate phases of Ti3Al, TiAl3, TiAl, TiC and Ti2AlC, as well as the starting reactants. In comparison with the materials synthesized from TiH2/Al/TiC or Ti/Al/C powder mixtures, more impurity phases were found in the synthesized Ti3AlC2. Analysis of the sintering curves as well as the intermediate phase formation during the reactive sintering process revealed that incomplete dehydrogenation of TiH2 postponed the formation of intermediate phases, which in turn resulted in final products with more impurity phases. [Copyright &y& Elsevier]

The present study describes the influence of β stabilizers (namely Fe and Cr) on the microstructural evolution and mechanical behavior of Ti–6Al–4V alloy fabricated by direct energy deposition. As the β stabilizer content increases from 1 to 4 wt%, the coarse columnar-grained morphology typical of additively manufactured Ti–6Al–4V is significantly refined, with a columnar-to-equiaxed transition. Furthermore, reheating of the deposited layers by the deposition of overlaying layers during fabrication induces an element partitioning effect, resulting in the formation of fine-grained α and isothermal ω. Hence, the heat profile during direct energy deposition resembles conventional solution and aging treatments. In addition, increasing the amount of β stabilizer steadily increases the room temperature strength of the Ti–6Al–4V alloy. The alloy with 4 wt% Fe showed the maximum strength, of ∼1.5 GPa. • The columnar-to-equiaxed transition of microstructure was achieved in the direct energy deposited Ti–6Al–4V alloy with the addition of Fe and Cr. • The maximum room temperature strength of the Ti–6Al–4V with 4 wt% Fe alloy reaches ∼1.5 GPa. • The reheating phenomenon caused by deposition of overlying layers during direct energy deposition resembles conventional solution and aging treatments. • With an increasing amount of β stabilizer, the phase constituents in the Ti–6Al–4V alloy changed from αʹ.→ αʹ+α+ω+β → α+ω+β [ABSTRACT FROM AUTHOR]