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Regulating morphology and composition of catalysts is of grand importance to enhance their electrocatalytic activity in energy-related fields. Herein, an electrocatalyst of ruthenium-cobalt oxide (Ru-CoO) heterojunctions decorated with atomically dispersed Ru atoms is constructed with a simple and effective salt fractionation approach. The morphology and structure of the resulting Ru-CoO were analyzed using scanning electron microscopy, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, powder X-ray diffraction, N 2 sorption, and X-ray photoelectron spectroscopy, respectively. Owing to the synergistic contributions of heterostructured Ru-CoO with abundant interfaces and single atomic Ru at doping level, the resulted Ru-CoO exhibits excellent bifunctional electrocatalytic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performances along with long-term durability under alkaline electrolytes. To attain a current density of 10 mA cm−2, the hybrid needs overpotentials of 340 and 359 mV for the OER and HER, respectively, excelling many reported catalysts to date. Importantly, this work paves a new route toward the development of efficient catalysts for the future of hydrogen economy. [Display omitted] • The Ru-particles-incorporated cobalt oxide (Ru-CoO) hybrid decorated with well-dispersed Ru atoms is synthesized. • The 3D nanosheet structure can offer rich pores, numerous accessible catalytic sites, and high conductivity. • The nanocomposite shows efficient catalytic performance with long-term stability for the OER and HER under alkaline media. [ABSTRACT FROM AUTHOR]

Novel Pr 3+ , Ho 3+ , and Er 3+ single-doped Ca X Sr Y Ba 1−X−Y WO 4 phosphors were successfully prepared via a facile hydrothermal method. The hydrothermal process was conducted in aqueous condition without the use of any organic solvent, surfactant, or catalyst. The effects of doping-host composition and RE 3+ doping concentration on the emission intensity were investigated to optimize the luminescent properties of Ca X Sr Y Ba 1−X−Y WO 4 :RE 3+ phosphors. Experimental results demonstrate that the morphologies of the products vary gradually and regularly with the change of the host composition, in which the anisotropic growth played a key role. Moreover, the down-conversion emissions of Pr 3+ , Ho 3+ , and Er 3+ in Ca X Sr Y Ba 1−X−Y WO 4 host were successfully realized. After optimizing the luminescent properties, Ca 0.4 Sr 0.6 WO 4 :0.01Pr 3+ , Ca 0.8 Sr 0.2 WO 4 :0.01Ho 3+ , and Ca 0.6 Sr 0.4 WO 4 :0.005Er 3+ exhibited optimal luminescent property, with orange, yellowish-green, and green emissions, respectively. [ABSTRACT FROM AUTHOR]

Highlights: [•] The reaction pathway of nanostructure clad particles with Ni/Al=3:1 is from NiAl to Ni3Al compound. [•] The size of Ni/Al clad particles plays a key role in the presence of NiAl precipitate. [•] The rate of reaction of system under thermal loading on local region is more rapid compared to that of system under thermal loading on whole system. [•] The propagation of reaction front is limited by mass transfer for 3Ni+Al clad particles. [ABSTRACT FROM AUTHOR]

Abstract: Zn/Co/Fe composite oxide nanotubes were successfully synthesized using a 1:2:1 molar precursor solution of Zn(NO3)2, Co(NO3)2 and Fe(NO3)3 and anodic aluminum oxide as the substrate. To obtain the arrays of Zn/Co/Fe oxide nanotubes inside the anodic aluminum oxide templates, the precursor with template was treated in a muffle at 500°C for 1h. Characterization of the nanotubes using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) indicated that they are about 10μm in length, with an outer diameter of about 200nm and a wall thickness of about 30nm. The grains that formed the nanotubes were about 10–20nm in diameter. The products were also characterised by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Magnetization measurement was carried out using a vibrating sample magnetometer (VSM) at room temperature and showed that the coercivity of Zn/Co/Fe oxide nanotubes was small, ∼30Oe. Therefore, Zn/Co/Fe oxide nanotubes could be easily prepared using this method and might be applied as catalysts, magnetic materials and microwave absorbers. [Copyright &y& Elsevier]

• AlSi10Mg components were fabricated by SLM under different VED ranges, i.e. conduction, transitional, and keyhole modes. • The KDP was consisted of α-Al, with less than 15 μm grain size, and enclosed by ~200 nm eutectic Si cellular networks. • No preferential crystallographic orientation could be observed within the KDP. • The high-stress exponents indicate that the creep behavior is controlled by dislocation-particle interactions. • The SLM AlSi10Mg fabricated in the transition mode exhibits a high tensile strength combined with reasonable ductility. The effect of the volumetric energy density (VED) on the keyhole formation, microstructural evolution and associated mechanical properties of AlSi10Mg fabricated by selective laser melting (SLM) has been systematically investigated. The results indicated that three melting modes could be distinguished during the laser melting process, corresponding to different VED ranges, i.e. conduction mode (<50 J mm-3), transitional mode (~50–65 J mm-3), and keyhole mode (>65 J mm-3). A high VED not only produced keyhole defects and hydrogen pores, but also generated two types of molten pool, i.e. a general shallow molten pool (GSP) and a keyhole-induced deep molten pool (KDP). The GSP was mainly consisted of an α-Al matrix, with ~30 µm grains size, and enclosed by a ~500 nm eutectic Si cellular network. The grain size of the KDP was less than 15 µm, and it has both a finer Si network (~200 nm) and nano-scale Si particles. No preferential crystallographic orientation could be observed within the KDP, while a strong texture along<111>orientation was exhibited in the GSP. These were responsible for the different mechanical properties of the SLM parts under different melting modes. The related mechanisms of the GSP and the KDP formation are comprehensively discussed and a correlation between the microstructure and the mechanical properties is also outlined. [ABSTRACT FROM AUTHOR]

Stress has a strong impact on the magnetization and magnetostriction of magnetic materials due to the magneto-elastic coupling. It offers a clue to understand the 2–5 times enhancement on the magnetostriction of Fe–Ga alloys with rare-earth elements doping. In this article, the stress states of melt-quenched and melt-spun (Fe 0.83 Ga 0.17) 100- x Tb x (x = 0–0.47) alloys were measured by high energy X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) technique. The macroscopic residual and microscopic stress of different Tb doped alloys were deduced from the shift and broadening of diffraction peaks and the deviation of the identified 1st Fe–Fe and 2nd Ga–Ga bond length. Rietveld refinement confirmed that the dissolved Tb atoms can replace the Fe/Ga site while small-angle neutron scattering (SANS) showed the presence of Tb-rich nanoscale precipitates. The effect of external stress loading and Tb doping on magnetization and magnetostriction of the modified Fe–Ga alloys was compared and discussed. We propose that the magnetization and magnetostriction of Fe–Ga alloys can be controlled through stress engineering by manipulating the magnetic domain structure through chemical doping or mechanical loading. Image 1 • Stress engineering can effectively enhance magnetostriction and tune magnetization. • Atomic-scale Ga–Ga pairs, Tb-rich nano-precipitates and spin-misalignment coexist. • Sizeable local atomic and macroscopic residual stress varies with Tb concentration. • Element doping and stress loading has similar effect on modifying domain structure. [ABSTRACT FROM AUTHOR]

Titanium alloys produced by additive manufacturing show excellent mechanical properties at room temperature. However, their deformation behavior at low temperature is still not fully understood. In this study, the microstructural evolution and tensile behavior of the near-α titanium alloy Ti-6.5Al-2Zr-Mo-V (TA15), fabricated via laser powder bed fusion (LPBF), were determined at both 25 °C and −196 °C. The LPBFed TA15 alloy shows the microstructure of α laths and acicular α′ martensite due to the rapid cooling rate during LPBF processing. Pyramidal slip and numerous twins, including nano-twins and triple twins, were activated at cryogenic temperature, leading to the high ultimate tensile strength (UTS) up to 1750±8 MPa and yield strength (YS) up to 1548±25 MPa, which is higher than the strength at room temperature (YS∼1103 MPa, UTS∼1281 MPa). The dominant deformation mechanism changes from dislocation slip to twinning with decreasing temperature, leading to uniform deformation with an elongation of 5.2±0.1 %. The results can guide the control of the microstructure of LPBFed near-α titanium alloys at cryogenic temperature. • The LPBFed TA15 showed excellent tensile strength (YS∼1548 MPa, UTS∼ 1750 MPa, elongation∼5.2±0.1 %) at −196 °C. • A large number of 10 1 ̅ 1 < 10 1 ̅ 2 > nano-twins, including the nanotwins and triple twins, were activated at cryogenic temperature. • The dominant strengthening mechanism varies from dislocation strengthening to twin boundary strengthening. [ABSTRACT FROM AUTHOR]

The unique transport properties make CuInTe 2 emerge as a promising thermoelectric material. However, the intrinsically low carrier concentration and high lattice thermal conductivity of CuInTe 2 limit its thermoelectric performance. In this work, firstly, we investigate the influence of excess Te on the electrical and thermal transport properties of CuInTe 2. The results suggest that excess Te can act as both electron acceptors and phonon scattering centers, which simultaneously optimizes the carrier concentration and impedes the propagation of high-frequency phonons. Furthermore, the substitutional Ag/Cu defects integrated with excess Te lead to a further reduction in lattice thermal conductivity. DFT calculations indicate that the substitution of Ag for Cu can reduce phonon group velocity and intensify the acoustic phonon scattering, which agrees well with our experimental data. Finally, a high zT value of 1.03 is obtained @840 K for sample Cu 0.8 Ag 0.2 InTe 2.2. This study demonstrates a facile but effective approach to boost the thermoelectric performance of chalcopyrite compounds. [Display omitted] • Excess Te optimizes the carrier concentration and impedes the propagation of high-frequency phonons. • The introduction of Ag on Cu sites results in a further reduction in lattice thermal conductivity. [ABSTRACT FROM AUTHOR]

Abstract: Angle-dependent Raman scattering is performed on an m-plane AlN bulk crystal. The angular dependence of A 1(TO) phonon mode shows strongly anisotropic behavior that the Raman intensity in xx polarization is 6.5 times larger than that in zz polarization. Both anisotropy ratio and phase difference between the independent Raman tensor elements Rxx and Rzz of the A 1(TO) mode are derived from the Raman spectra. It is found that the |Rxx |/|Rzz | ratio is up to 2.54, which is noticeably higher than that of wurtzite GaN (1.30) and ZnO (1.02). [Copyright &y& Elsevier]

Preventing anisotropy in materials produced by laser powder bed fusion (LPBF) has become a major challenge. In this work, we achieved good mechanical properties in LPBF-produced titanium by promoting the columnar to equiaxed transition (CET) though alloying with copper to produce a Ti-5 wt% Cu alloy. Horizontal specimens at different build heights all consisted of mainly equiaxed prior-β grains (∼ 13 µm) with ultrafine α lamellae (∼ 0.19 µm width) that exhibited weak textures. Thermal cycling along the build direction (BD) not only promoted the segregation of Cu from top to bottom, but also converted the compressive residual stress (−109.0 ± 22.2 MPa) to tensile residual stress (10.4 ± 9.7 MPa). The friction coefficient, hardness, and wear resistance found in different sections of the build were all very similar. The wear mechanism of the specimens was a combination of abrasive and delamination wear. The yield strength, ultimate strength, and elongation of specimens from the top section of the build were 993 ± 18 MPa, 1145 ± 60 MPa, and 8.6 ± 0.2%, respectively. While the strength of the middle and bottom specimens remains at the same level as that of the top specimen, a reduction in elongation was observed due to the segregation of Cu. Additionally, the strength of vertical specimens was about 50–70 MPa higher than that of horizontal specimens, which is thought to be caused by residual stress gradient along the BD. • Cu alloying promoted the columnar to equiaxed transition (CET) in the Ti-5Cu alloy produced by laser powder bed fusion. • The microstructures consist of mainly equiaxed prior-β grains with ultrafine α lamellae that exhibited weak textures. • Due to the promotion of CET, the hardness and wear resistance in different sections of the build were all very similar. • Cu segregation and residual stresses are the main reason for the lower elongation and higher strength in vertical specimens. [ABSTRACT FROM AUTHOR]

High strength Al-Cu alloys are of great interest for processing using additive manufacturing for aerospace applications. In this study, a Ti-modified Al-Cu alloy was successfully processed by in - situ alloying laser powder bed fusion (LPBF). The relationship between the volumetric energy density (VED) and the densification of a Ti-modified and unmodified Al-Cu alloy was investigated. The results showed that a high-density, crack-free Al-Cu alloy can be achieved with the addition of Ti. Hot cracks occurred along the coarse columnar grains in the unmodified Al-Cu alloy due to the severe stress concentrations arising during the LPBF process. The elimination of hot cracks was attributed to the decrease of grain size and the change of grain morphology from columnar to equiaxed with the Ti addition. The tensile properties of the Ti-modified Al-Cu alloy were significantly improved with a yield strength of 200 MPa, an ultimate strength of 289 MPa, and an elongation to failure of 8 %. The strengthening mechanisms including grain refinement strengthening, solid solution strengthening and second phase strengthening were quantified and the fracture mechanism was discussed. The tribological results showed that a low wear rate of 3.03 × 10−4 mm3 N−1 m−1 was achieved in the alloy with Ti modification, while unmodified alloy showed a poor wear resistance. The study demonstrates a novel method to develop advanced Al-Cu alloy with high density, strength and tribological resistance by in - situ alloying LPBF. • Al-Cu alloy and Ti-modified Al-Cu alloy was processed by laser powder bed fusion. • The Ti-modified Al-Cu alloy with crack-free structure was obtained. • The Ti-modified specimen showed better wear resistance and mechanical properties. [ABSTRACT FROM AUTHOR]

Iron nitrides have a wide spectrum of applications in wear resistance coatings, catalysis, biomedical fields and spintronics due to their diverse phase structures. Thus it is important to fundamentally understand and precisely control the phase structures of iron nitrides. However, there is no work showing structural relationships among the phases. Here a structural commonality of iron nitride is proposed. All iron nitrides are alternately composed of close packed Fe atomic layers and interstitial N atomic layers, where the Fe layers have ideal or quasi two dimensional hexagonal configurations. Based on this commonality, successive phase evolution of iron nitride epitaxial films on MgO(111) substrate was realized. And a nitrogen flow rate-substrate temperature phase diagram was constructed. Moreover, the structural commonality is also found in other transition metal nitrides. Therefore, these results not only offer new insights into the phase evolution of iron nitrides but also provide a good choice for the fabrication of the heterostructures of transition metal nitrides with different crystal structures. • Iron nitrides have a structural commonality consisting of Fe and N atomic layers. • The commonality was verified by phase evolution of iron nitride epitaxial films. • This commonality provides new insights into the structure of metal nitrides. • These results would facilitate the application of nitrides in heterostructures. [ABSTRACT FROM AUTHOR]

Abstract In practice, the poor formability and high degradation rate of Mg-based alloys are perceived as two major limitations for their more extensive applications in the biomedical field. Selective laser melting (SLM), as one of the advanced additive manufacturing techniques, is potential for the manufacturing of customized Mg-based implants with improved formability and corrosion resistance. Moreover, the integration of bioactive glass (BG) into Mg-based alloys could endow the materials with further enhanced corrosion resistance and favorable biological performance. In the current work, biomedical Mg-based biodegradable composites (ZK30/xBG, x = 0, 5, 10, 15 wt%) with ZK30 alloy as the matrix and BG (45S5) as the reinforcement were fabricated by SLM. The results showed that the BG particles homogeneously distributed in the matrices of SLM-fabricated ZK30/xBG composites. Meanwhile, the introduction of the BG particles led to improved microhardness of the composites. When immersed in simulated body fluid (SBF), more precipitations (primary Ca–P compounds and partial Mg(OH) 2) formed on ZK30/10BG and ZK30/15BG surfaces compared to ZK30 and ZK30/5BG group. The hydrogen evolution and electrochemical polarization tests showed that corrosion resistance of various specimens was in the following order: ZK30/10BG > ZK30/5BG > ZK30/15BG > ZK30. In addition, the in vitro cell viability results showed that ZK30/10BG and ZK30/15BG were more cytocompatible than ZK30 and ZK30/5BG. Overall, these results indicate that the combination of SLM technique and BG integration could be used to manufacture ZK30/xBG composites with enhanced corrosion resistance and favorable formability. Moreover, the ZK30/10BG composite is promising for orthopedic applications considering its combination of favorable bioactivity, corrosion resistance and cytocompatibility. Highlights • Selective laser melting was applied to fabricate ZK30/Bioactive Glass composites. • Degradation rate of ZK30 matrix obviously decreased with the introduction of BG. • Cytocompatibility was improved as the addition of BG. [ABSTRACT FROM AUTHOR]

Abstract The gradient nanograined metals have the unexpected combination of high strength and high ductility. However, the detailed dynamic and continuous process of deformation mechanism at nanoscale need to be further understood. Herein, we report the deformation behavior and microstructure evolution of gradient-nanograined body-centred cubic alloys using molecular dynamics simulations. An analytical model is also established to predict the strength for nanograined alloys. The results show that the alloying can soften the gradient-grained and random-nanograined Fe-based alloys. With the increasing Ni concentration, dislocation density decreases, due to the fact that the Ni solute increases stacking fault energy and the deformation twinning acts as a strong obstacle to suppress dislocation motion. The gradient distributions of strain and stress in gradient-nanograined metals occur due to the plastic incompatibilities, resulting in the inhomogeneous deformation of gradient-nanograined Fe and alloys. In addition, the inverse gradient-nanograined distribution, including large grain in the top surface and small grain in the central region, generates in random-nanograined alloys. It is owing to the grain growth in surface layer, resulting in the gradient strain and stress. Interestingly, the nucleated dislocation network and the deformation twinning considered as a reduction of dislocation mean free path decline rapidly with the increasing grain size for gradient-nanograined structure. The theoretical modeling determines the total strength derived from the individual contributions of different strengthening mechanisms, revealing that the grain boundaries dominate the yield strength and the back stress contributes the most to the straining hardening in nanograined materials. Graphical abstract Image 1 Highlights • Plastic deformation of gradient nanograined metals is studied by MD simulation. • The alloying results in the strengthening-softening trade-off. • Strain-induced strengthening is revealed owing to the gradient strain fields. • Theoretical model predicts straining hardening responses. [ABSTRACT FROM AUTHOR]

Abstract A TiC-Fe surface gradient coating was prepared on the surface of pure titanium by a simple two-step heat-treatment process (1150 °C × 5 min + 1000 °C × 10 h). The phase composition, microstructure, nanoindentation hardness, elastic modulus, fracture toughness, and adhesion strength of the TiC-Fe surface gradient coating were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), nanoindentation testing, and scratch testing. The results reveal that the TiC-Fe surface gradient coating was composed of dense TiC grains and a small amount of α-Fe. The TiC-Fe surface gradient coating was divided into three zones according to the variation in the volume fractions of TiC particulate and α-Fe phase. These zones were labeled as follows: a columnar TiC zone (I zone), a large particle TiC zone (II zone) and a large bulk TiC zone (III zone). The formation process and mechanism of the TiC-Fe surface gradient coating include the nucleation growth of TiC grains, followed by diffusion and in situ reactions between titanium and carbon. The nanoindentation hardness and elastic modulus for cross section of the TiC-Fe surface gradient coating ranged from 19.1 to 31.7 GPa and from 368.1 to 464.3 GPa, respectively. The fracture toughness values of I zone, II zone and III zone are 3.5, 1.6 and 3.1 MPa m1/2, respectively, and these values largely depend on composition and microstructure. Investigations of crack surface morphologies indicate that radial cracks at the corners of the indentation originate from the crossing of slip bands and that the toughening mechanism was mainly crack deflection and bridging. In addition, the scratch testing indicated that the coating exhibited excellent coating/substrate adhesion strength. Highlights • A TiC-Fe coating was fabricated by a simple two-step heat-treatment process. • The grain size and volume fraction of TiC presented a graded distribution. • The formation mechanism of the coating was the in situ solid phase diffusion reaction. • The fracture toughness values of the coating were 1.6–3.5 MPa m1/2 with 76%–99% TiC content. [ABSTRACT FROM AUTHOR]

Abstract Tantalum-tantalum carbide (Ta-TaC) core–shell rod-reinforced iron-based composites were designed and fabricated by in situ solid-phase diffusion reaction at 1150 °C for 5, 10, 15, 20, and 80 min, respectively. Phase composition, microstructure, impact toughness, micro-hardness, and elastic modulus of the composite, morphologies and grain sizes of TaCs were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, impact test, and nano-indentation test. Furthermore, formation kinetics of TaC-Fe shell layer was analyzed by measuring the thickness of pure TaC layer as a function of heat treatment time and temperature. Results indicated the generation of dense and compact TaC layer around the Ta rod by in situ solid-phase diffusion reaction, and together they were designated as the Ta-TaC core–shell rod. Predominant features of the Ta-TaC core–shell rod included a gradient nanostructured TaC-Fe shell layer and a Ta core. Predominant phases of the Ta-TaC core–shell rod-reinforced iron-based composite were Ta, TaC, and α-Fe phases. Kinetic results of TaC-Fe shell layer exhibited parabolic relationship between the thickness of pure TaC layer and annealing time, and growth rate constant for pure TaC layer was estimated to be 6.25 × 10−8 cm2 s−1. TaC particles in TaC-Fe shell layer preferred a perfect cube morphology enclosed by {100} facets with minimized total surface free energy. Grain size of TaC increased gradually from about 150 to 500 nm with the increasing distance from the interface of Ta core/TaC-Fe shell layer to the substrate. The Ta-TaC core–shell rods play an important role in improving the mechanical properties of the composite. Micro-hardness of the TaC-Fe shell layer was in the range of 10.4–24.8 GPa, which is 3–8 times than that of the substrate due to the dense and compact TaC. Impact toughness of the composite was 100.6 J cm−2, which is markedly higher than that of the gray cast iron (7.8 J cm−2). Excellent impact toughness of the composite is mainly attributed to Ta core of Ta-TaC core–shell rod, which undergoes a large plastic deformation under external forces. Moreover, the compact TaC distributed around Ta rod reduced split action to the matrix, and the matrix absorbed large amount of crack propagation energy. Highlights • Ta-TaC core–shell rod was in situ synthesized by solid-phase diffusion reaction. • The Ta-TaC core–shell rod includes a gradient TaC-Fe shell layer and a Ta core. • The maximum hardness was 24.8 GPa attributed the dense and hard TaCs. • The impact toughness was about 12 times higher than that of the gray cast iron. • High impact toughness of the composite was due to the Ta core with high toughness. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have been used as sacrificial templates to fabricate porous metallic oxides. However, its usage is limited in preparing rare earth perovskite-type oxides, which are usually synthesized by sol-gel method. Herein, sol-gel route was employed to construct the uniform La/Fe MOFs, completed in several seconds at room temperature. The fabricated LaFeO 3 /La 2 O 3 , LaFeO 3 and LaFeO 3 /Fe 2 O 3 have porous structure, and the LaFeO 3 possesses the largest specific surface area of 18.16 m2/g. Besides, abundant oxygen species exist on the surface of LaFeO 3 /La 2 O 3 and LaFeO 3 , with percentages of 68.13 % and 64.15 % in O 1 s spectra, respectively. Benefit from the morphology structure and elements states, the LaFeO 3 -based sensor exhibits an ultra-high response of 258.4–100 ppm n-propanol, and the LaFeO 3 /La 2 O 3 -based sensor possesses the detection limit of 0.16 ppm, at a quite low working temperature of 100 ℃. This work provided a facile, universal, and adjustable approach to design perovskite metal oxides for ultra-sensitive detection of various gases. • This synthesis of materials with porous is facile, universal, and timesaving. • The obtained LaFeO 3 /La 2 O 3 and LaFeO 3 possess large content of surface oxygen species. • The sensor based on LaFeO 3 displays a response of 258.4–100 ppm n-propanol. • The sensor exhibits low power consumption, with an operating temperature of 100 °C. [ABSTRACT FROM AUTHOR]

Hierarchical nanostructures Sn 1−0.25x Cu x S 2 flower-like photocatalyst with high visible-light photocatalytic activity and absorption capacity was synthesized via a facile one-pot solvothermal method. The morphology, crystal structure, optical and photocatalytic property of the as-prepared samples were thoroughly investigated by various means. XRD results indicated that Cu ions entered into the crystal lattice of SnS 2 without deteriorating the original crystal structure. The adsorbing capacity of obtained Sn 1−0.25x Cu x S 2 photocatalyst was 7.2 times and 2.9 times higher than SnS 2 for the removal of organics pollutants, respectively. Furthermore, Sn 1−0.25x Cu x S 2 photocatalytic exhibited much higher photocatalytic activity than the pure SnS 2 towards the degradation of RhB and DB under visible light (λ ≥ 420 nm), more than 95% DB and RhB molecules could be eliminated within 2 h. The enhanced adsorption capacity of the Sn 1−0.25x Cu x S 2 for organic pollutants was attributed predominantly to its high specific surface areas and appropriate pore size distribution. Superior photocatalytic activity profited from the large light responded region and efficient separation of photo-generated electron-hole pairs. A possible visible light photocatalytic mechanism of Sn 1−0.25x Cu x S 2 was proposed. Therefore, the Sn 1−0.25x Cu x S 2 flower-like photocatalyst could be a potential applications for water splitting, new fuels synthesis and environmental remediation under natural sunlight. [ABSTRACT FROM AUTHOR]

Mg is a potentially biomaterial for bone implant due to its biodegradability and biomechanical compatibility. However, the too fast degradation rate limits its clinical application. In the study, both alloying treatment and laser rapid melting were applied to slow down its degradation rate. The microstructure, mechanical properties and degradation behavior of the Mg x Sn ( x = 0–7 wt %) alloys were investigated. With Sn content increasing, the grain sizes decreased, while the new Mg 2 Sn phase increased. The refined grain slowed the degradation rate due to the reduced segregation. While the Mg 2 Sn phase accelerated the degradation rate owing to the couple galvanic corrosion. Thus, the optimal degradation behavior was obtained with a balanced grain size and Mg 2 Sn phase volume fraction. Besides, the compression strength increased firstly (up to 5 wt %) and then decreased with Sn increasing. [ABSTRACT FROM AUTHOR]

Abstract: SnS2 microspheres composed of submicron-sized flakes were successfully prepared via a simple surfactant-free hydrothermal reaction route at 240°C for 12h, using SnCl4 and Na2S as reactants. The powders were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The X-ray diffraction pattern confirmed that the SnS2 microspheres had a single-phase hexagonal structure. The SEM micrographs indicated that these microspheres with the size of ∼30μm in diameter were mainly constructed by self-assembly of submicron-sized SnS2 flakes. The effect of reaction temperature and the amount of mineralizer (urea) on the formation of SnS2 microspheres under hydrothermal conditions were investigated and a possible formation mechanism was preliminarily presented. [Copyright &y& Elsevier]

• Asymmetric supercapacitor based on all-conducting-polymer hydrogel electrodes. • Integrated design of electrode and electrolyte with the same substrate materials. • Strong mechanical flexibility and durability along with high energy density. • Positive and negative electrodes can be used interchangeably. • Available in series without distinguishing between positive and negative. [Display omitted] Flexible supercapacitors are promising flexible energy storage devices. However, manufacturing devices with high energy density, stable energy supply under harsh deformation, and more efficient modular application is still a challenge. Here, an all-gel-state integrated asymmetric flexible supercapacitor based on poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) and polypyrrole (PPy) composite hydrogel electrodes with an interchangeable positive and negative electrode was fabricated. The device has robust flexibility and mechanical durability, with an elongation at break of 286% at a tensile strength of 22.3 MPa and a capacitance retention rate of 98% after 1000 bending cycles, as well as fascinating electrochemical properties, with an energy density of 397.99 μWh cm−3 and a capacitance retention rate of 88.1% for 10,000 charges/discharge cycles. Moreover, the positive and negative electrodes of this asymmetric device can be used interchangeably, and it can power the light-emitting diodes (LEDs) without distinguishing between positive and negative. This design concept will perhaps open a new trend in the design of high-energy-density flexible energy storage devices. [ABSTRACT FROM AUTHOR]

• FeCoCrNiMoSi x (x = 0.5, 1.0, 1.5) HEAs were fabricated by SPS under 1150 °C. • Hardness of FeCoCrNiMoSi 1.5 reached 1186 HV. • High corrosion potential of Si makes FeCoCrNiMoSi 1.5 exhibits great corrosion resistance. • The oxidation properties FeCoCrNiMoSi 0.5 were greater than that of other FeCoCrNiMo HEAs. • Different properties can be obtained through controlling Si content. FeCoCrNiMoSi x (x = 0.5, 1.0, 1.5) high-entropy alloys (HEAs) were successfully fabricated by spark plasma sintering (SPS). The microstructure, tribological properties, oxidation behaviors and corrosion resistance of the HEAs were systematically investigated. The experimental results showed that the microstructure mainly consisted of Fe-rich face-centered-cubic (FCC) phase, Mo-rich FCC phase solid solution and various Si-rich intermetallics, where the elevated Si content coarsened the primary Mo-rich phase into dendritic eventually. These Mo-rich dendrites possessed strong covalent-dominant atomic bonds that enhanced the microhardness (from 725 to 1186 HV) and wear resistance. The FeCoCrNiMoSi 0.5 HEA exhibited an outstanding combination of relatively high wear resistance and the strongest oxidation resistance under 800 °C among the three alloy compositions. The corrosion resistance of HEAs showed an increasing trend with the elevated Si content, and FeCoCrNiMoSi 1.5 presented the best performance. [ABSTRACT FROM AUTHOR]