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Ti-6Al-3Nb-2Zr-1Mo (Ti6321) alloy, as a new type of marine metal, has excellent corrosion resistance and mechanical properties, but its application is restricted by the traditional manufacturing processes. Wire-arc directed energy deposition (DED) has some incomparable advantages in the efficient and customized fabrication of large/extra-large components, which makes it become a potential manufacturing process for the fabrication of Ti6321 alloy components. However, the formability and corresponding performance evaluation of wire-arc DEDed Ti6321 alloy remains unknown. Here, for the first time, the microstructure, mechanical properties and corrosion resistance of wire-arc DEDed Ti6321 alloy was characterized and compared with rolling, and the relationship between process-microstructure-properties was established. Results show that the full lamellar α+β structure of the DEDed specimens demonstrated better corrosion resistance than the near equiaxed α p + lamellar α s /β structure of rolled specimens. This is owed to the higher grain boundary density, more content of β phase and slighter element segregation of the DEDed specimens, resulting in a more uniform and stable passivation film on its surface. Meanwhile, the grain morphology and low dislocation density of the DEDed specimens causing in lower tensile strength (decrease by ∼15.6 %) but higher elongation (increase by ∼41.5 %) than the rolled specimens. Due to the presence of coarse prior-β grains, the DEDed specimens show expected anisotropy in building direction and traveling direction, but overall exhibits sufficient mechanical properties, which exceed the execution standard. This study verified the feasibility of fabricating Ti6321 alloy with idea properties by wire-arc DED, and provides a potential strategy for the production and practical application of large-size Ti6321 alloy components. [Display omitted] • The fabrication of Ti6321 alloy by wire-arc DED was conducted in-depth and systematic research for the first time. • Comparison between the mechanical properties and corrosion resistance of rolled and DEDed Ti6321 alloy was conducted. • Relationship between the process, microstructure and properties of DEDed Ti6321 alloy were studied. [ABSTRACT FROM AUTHOR]

Abstract Fabrication of transparent TIG (Tb 3 Fe 5 O 12) ceramics promising for 1.3–1.5 μm optical isolator was successful for the first time by a solid-state reaction between Tb 4 O 7 and Fe 2 O 3. The obtained TIG ceramics was free from grain boundary phases and inclusions but some residual pores were observed in the depth direction. Its in-line transmittance reached ca. 50% in infrared region of 1.1–2.0 μm. Faraday rotation angle of the TIG ceramics was 350deg./cm for 1300 nm, which is about 1.5 times larger than that of the YIG (Y 3 Fe 5 O 12) single crystal. Removal of those residual pores can significantly improve optical properties. Highlights • Succeeded to produce transparent TIG (Tb 3 Fe 5 O 12) ceramics by a simple solid-state reaction of Tb 4 O 7 and Fe 2 O 3 powders. • No wavelength dependency of the in-line transmittance. • Faraday rotation characteristics of the polycrystalline TIG ceramics as same as its single crystal counterpart (350 deg./cm). [ABSTRACT FROM AUTHOR]

Abstract In this research, we designed a rod-like shaped MnO 2 /Fe binary composite by loading magnetic Fe nanoparticles on MnO 2 rods. The co-existence of MnO 2 and Fe shows balanced impedance match and dual magnetic-dielectric loss ability. When MnO 2 /Fe sample presenting rod-like shape, the dielectric loss ability can be further boosted, owing to the formation of conductive network. After tuning weight ratio of Fe in a suitable value, the minimum reflection loss value (RL min) can up to 35.0 dB with a matched thickness of 1.5 mm. Meanwhile, the effective frequency absorption region (f E) covers 5.6 GHz. To better understand the electromagnetic attenuation mechanism, the effects of components, microstructure as well as weight ratios on the electromagnetic absorption properties have been discussed in depth. Highlights • Magnetic Fe nanoparticles are applied to decorate MnO 2 rods. • The weight ratio of Fe and MnO2 is tunable. • f E value can up to 5.6 GHz with a thickness of 1.5 mm. • The electromagnetic absorption mechanism is well discussed. [ABSTRACT FROM AUTHOR]

Abstract This paper mainly describes a sacrificial template synthetic approach for the fabrication of the Ag-nanosheet-assembled hollow tubular array by using an electrochemical deposition in the mixed solution of silver nitrate and citric acid on gold layer pre-coated ZnO nanorods. The tubular array is formed by an outer shell of Ag-nanosheet blocks and corresponding an inner hollow structure, this internal hollow structure is attributed to the completely corroded ZnO nanorods. Such Ag-nanosheet-assembled hollow tubular array exhibits excellent surface-enhanced Raman scattering (SERS) performance including rich surface activity, good selectivity and high sensitivity. Using this array as sensitive SERS substrate with good signal uniformity and reproducibility, it has been revealed that the detecting limit of R6G solution can be to10−12 M, presenting the potential applications of the SERS substrate materials in rapid detection of environmental organic pollutants. Graphical abstract Image 1 Highlights • A sacrificial template approach for the synthesis of the Ag hollow tubular array. • The synthesis of Ag hollow tubular array was two-step electrodeposition method. • The hollow tubular array was form of an outer shell of Ag-nanosheet blocks. • The Ag array was used as SERS substrate with surface activity and sensitivity. • The substrate detecting limit was 10−12 M, using detection of organic pollutants. [ABSTRACT FROM AUTHOR]

Abstract We have tailored a photovoltaic-photoelectrochemical (PV-PEC) cell by integrating p-n Cu 2 O thin films and ZnO nanorods (NRs) on conductive oxide substrates for water splitting. The combined PV-PEC cell can benefit not only from the high oxidation potential of ZnO NRs but also from the visible range light absorption of Cu 2 O photovoltaics. Differently from previous methods to fabricate p-n Cu 2 O junctions, we employed the type transition from p-to n-Cu 2 O by a simple solution treatment and then p-Cu 2 O was coated on n-Cu 2 O to smoothen the p-n junction interface. We for the first time produced p-n homojunction Cu 2 O layers using the identical electrodeposition process. After Au thin film coating on n-Cu 2 O and p-n Cu 2 O layers by sputtering high-density ZnO NRs were grown by the hydrothermal method to construct the Z-scheme band structures. By comparing the photoresponses of ZnO NRs/Au/n-Cu 2 O and ZnO NRs/Au/p-n Cu 2 O, we could elucidate the effect of the built-in potential on PEC properties by p-n Cu 2 O. ZnO NRs/Au/p-n Cu 2 O showed the onset potential of −0.330 V which is more cathodic by 0.167 V than ZnO NRs/Au/n-Cu 2 O. Also, its photocurrent was 0.206 mA/cm2 under 0.2 V vs SCE which is 237% higher than that of ZnO NRs/Au/n-Cu 2 O. These enhancements are attributed to the internal electric field by the p-n junction and the efficient charge separation and migration by utilizing both the p-n junction and the Z-scheme. Graphical abstract Image 1 Highlights • PV-PEC cells have been prepared by integrating p-n Cu 2 O films and ZnO nanorods. • The type transition from p-to n-Cu 2 O was employed by a simple solution treatment. • The Z-scheme structure and the buried p-n junction work effectively for the system. • The photocurrent of ZnO NRs/Au/p-n Cu 2 O is 237% higher than that of ZnO NRs/Au/n-Cu 2 O. [ABSTRACT FROM AUTHOR]

Abstract A two-step cryorolling and aging process was developed to fabricate high strength and high electrical conductivity CuCrZr alloys. The microstructural evolution, mechanical and electrical properties of Cu-1Cr-0.1Zr (wt.%) alloys subjected to the two-step cryorolling and aging process were investigated. The results showed that this two-step process reduced the width of the deformation bands from 113 nm to 80 nm. The introduction of precipitates in the matrix during intermediate aging was responsible for the narrowing of the deformation bands. Even though the cryorolled sample underwent detwinning, its ultimate tensile strength improved by ∼35 MPa. Ordered face-centered cubic (fcc) Cr precipitates ∼5 nm in size were observed in the Cu matrix, and these precipitates had a pinning effect on the motion of boundaries. A desired balance between the ultimate tensile strength (648 MPa) and electrical conductivity (79.80% IACS) was achieved by the coexistence of refined deformation bands, nanoscale deformation twins and nanoprecipitates. Highlights • The two-step cryorolling and aging can reduce the deformation band width. • Despite undergoing detwinning, the strength of cryorolled sample is still enhanced. • The refined deformation bands, nano-twins and nano-precipitates co-exist. • A desired integration of tensile strength and electrical conductivity was achieved. [ABSTRACT FROM AUTHOR]

Abstract Hybrid (SiC+TiC)p/AZ91 nanocomposites were successfully fabricated by the combination of semisolid stirring and ultrasonic vibration. Then the nanocomposites were extruded at a low temperature of 270 °C with slow extrusion speeds of 1, 0.5 and 0.1 mm/s, respectively. The result showed that the distribution of hybrid nanoparticles was uniform both in the as-cast and as-extruded conditions. With decreasing the extrusion speed from 1 mm/s to 0.1 mm/s, the grain sizes of the nanocomposites were gradually decreased. The volume fraction of precipitated Mg 17 Al 12 phases was gradually increased while the average diameter was decreased. The externally applied hybrid nanoparticles and dynamic precipitated Mg 17 Al 12 phase could hinder the movement of grain boundary, contributing to the grain refinement. The yield strength of ∼345.6 MPa, ultimate tensile strength of ∼397.2 MPa and elongation of ∼5.2% was obtained in case of the nanocomposite extruded at 0.1 mm/s. The increment in the strength could be attributed to the addition of hybrid (SiC+TiC) nanoparticles, ultra-fine matrix grains and large amount of precipitated Mg 17 Al 12 phases. For the stage Ⅲ on the work hardening rate curve for the (SiC+TiC)p/AZ91 nanocomposite, the hybrid nanoparticles and dynamic precipitated Mg 17 Al 12 could impede the annihilation of dislocation while the refined matrix grains had the opposite effects. Graphical abstract Image 1 Highlights • Hybrid (SiC+TiC) nanoparticles were successfully added to the AZ91 matrix alloy. • Dynamic precipitated Mg 17 Al 12 were obtained during hot extrusion. • Hybrid nanoparticles and dynamic precipitates lead to superior tensile strength. [ABSTRACT FROM AUTHOR]

Abstract Developing of high efficient electrode materials for CO 2 reduction is very important in CO 2 conversion and recycling utilization. In this work, we have fabricated ZnS/Zn electrode using sulphur infiltration method. This method is a well-developed technology in surface treatment. ZnS/Zn electrode fabricated via sulphur infiltration method has a crucial advantage: because sulfur atomic is infiltrated into Zn substrate, a translation layer is formed and sandwiches between ZnS layer and Zn substrate. As a result, ZnS connects with Zn substrate firmly, and the exfoliation of ZnS layer from Zn substrate is avoided. The ZnS/Zn has been investigated as the cathode for CO 2 electro-reduction in propylene carbonate/tetrabutylammonium perchlorate (PC/TBAP) in membrane electrolysis cell. The current density of potentiostatic electrolysis remains stable at 6.72 mA/cm2 at voltage −2.4 V and the faradaic efficiency of CO formation reaches to 92%. Comparing with Zn electrode, ZnS/Zn exhibits higher catalytic activity. Highlights • Demonstrating that S-Infiltration is a feasible method for electrode preparation. • Avoiding that the exfoliation of electrode modification layer from the substrate. • ZnS/Zn electrode has large surface roughness that result high current density. • ZnS/Zn electrode shows high CO selectivity and catalytic activity. [ABSTRACT FROM AUTHOR]

Abstract In this work, 3D honeycomb-like carbon-coated Na 7 Fe 4.5 (P 2 O 7) 4 nanocomposites are fabricated by a simple sol-gel method and used as cathode materials for the sodium-ion batteries. The electrochemical results reveal that the 3D hierarchically porous Na 7 Fe 4.5 (P 2 O 7) 4 /C nanocomposites provide a high reversible capacity of 106 mA h g−1 at 0.5 C and a good rate performance (83 mA h g−1 at 2 C). After even 100 cycles at 1 C, 85% of the capacity retentions can be maintained in half batteries. The remarking electrode performance was attributed to the combination of 3D hierarchically porous structure, which facilitates electrolyte penetration into every corner and carbon coating can promote rapid electron transfer. Highlights • Na 7 Fe 4.5 (P 2 O 7) 4 /C composites were synthesized by sol-gel method firstly. • It possesses loosely honeycomb-like structure. • It was assembled sodium-ion full batteries firstly. • It exhibits brilliant electrochemical performance. [ABSTRACT FROM AUTHOR]

Abstract The large temperature dependence of electro-strain for Bi 0.5 Na 0.5 TiO 3 (BNT)-based ceramics limits their practical applications. In this work, Li-doped BNT-based lead-free multi-layer piezoelectric ceramic actuators are prepared by solid-state reaction synthesis method. The multi-layer actuator structure is fabricated by gradient doping, in which each layer corresponds to different compositions, with enhanced temperature stability compared to the single-layer one. For specific composition, it could achieve maximum electro-strain value at a certain temperature. Therefore, the electro-strain of each layer in this BNT-based multi-layer actuator could compensate each other at different temperatures with improved temperature stability. Consequently, the electro-strain of the five-layer structure varies less than ∼12% when the temperature changes from 50 °C to 130 °C, and a large electro-strain of 600 pm/V could be obtained at 70 °C. This work provides an effective approach by gradient doping to broaden the use temperature range for BNT-based actuators with improved temperature stability. Highlights • The BNT-based gradient doping multi-layer structure actuator is prepared. • The temperature stability of the multi-layer ceramics is greatly improved. • The strain of the five-layer ceramics varies less than ∼12% from 50 °C to 130 °C. • A large electro-strain of 600 pm/V could be obtained for the five-layer ceramics. [ABSTRACT FROM AUTHOR]

Abstract Oxide semiconductor Schottky barrier diodes (SBDs) were fabricated by using amorphous In-Ga-Zn-O (IGZO) semiconducting thin films with different atomic ratios. Higher rectification ratios and Schottky barrier heights (SBHs) were obtained when the oxygen partial pressure was high during the sputtering deposition of the IGZO films. The increase in Ga composition effectively enhanced the device characteristics, including the rectification ratio and the SBH of the SBDs. These properties were closely related to the control of oxygen vacancy concentration within the IGZO and the resulting conduction behaviors owing to Fermi-level pinning and tunneling current through the Schottky barrier. The fabricated SBD using IGZO with a higher Ga composition (In:Ga:Zn = 1.0:0.8:0.3) exhibited a rectification ratio of 8.3 × 106 and an SBH of 0.79 eV. Highlights • We fabricated Schottky barrier diodes using In-Ga-Zn-O oxide semiconductors. • Effects of oxygen partial pressures (PO 2) and film compositions were investigated. • PO 2 conditions during the sputtering has marked impacts on device characteristics. • Increase in Ga composition is effective for enhancing the diode performance. • Less amount of oxygen vacancies within the IGZO is preferred for the diodes. [ABSTRACT FROM AUTHOR]

Abstract In this work, we present our research on the fabrication of high power terahertz quantum cascade laser (THz QCL) with frequency at 4.4 THz and its demonstration in digital holographic imaging. The lasers described in this work are based upon the resonant-phonon active region design and semi-insulating surface-plasmon waveguide. The peak power varies with the size of the ridge and the maximum output power of 95 mW at 10 K in pulsed mode is obtained. The maximum working temperature is 80 K. Interestingly, by changing the injection current, the transverse mode of the laser can be switched between TM 00 mode and TM 01 mode. With such THz QCL as the light source, the lateral resolution of a home-built digital holographic imaging system can reach 80 μm. Highlights • Fabrication of high power 4.4 THz quantum cascade lasers. • The peak power reaches 95mW at 10K and the maximum working temperature is 80K. • Transverse mode of the laser is switched by changing the injection current. • The lateral resolution of a home-built digital holographic imaging system reaches 80μm. [ABSTRACT FROM AUTHOR]

Abstract Development of high-performance supercapacitors with high energy density is urgently required for energy storage device but remains challenging. In this work, novel NiCo 2 O 4 @Ni(OH) 2 (denoted as NCO-NH) core-shell nanoarrays were synthesized. Benefiting from the structural and compositional advantages, the NCO-NH core-shell nanoarrays exhibited high specific capacitances (2218.0 and 1796.0 F g−1 at current densities of 1 and 10 A g−1, respectively) and outstanding cycling stability (96.4% retention of the initial specific capacitance at 10 A g−1 after 5000 cycles). Using such NCO-NH nanoarrays as cathode and activated carbon as anode, an asymmetric supercapacitor (ASC) is further fabricated. This ASC device achieves a high energy density of 98.5 W h kg−1 at a power density of 800 W kg−1 (at current densities of 1 A g−1) and an energy density of 61.5 W h kg−1 at a high power density of 8000 W kg−1 (at current densities of 10 A g−1). This work highlights that construction of core-shell nanoarrays by coupling of bimetallic oxide with hydroxide could be a feasible way to obtain advanced electrode materials for high-performance supercapacitors. Graphical abstract Image 1 Highlights • NiCo 2 O 4 @Ni(OH) 2 core-shell nanoarrays have been successfully fabricated. • The core-shell nanoarrays electrodes showed high specific capacitance. • The core-shell nanoarrays electrodes exhibited outstanding cycling stability. • The ASC device based on core-shell nanoarrays can deliver high energy density. [ABSTRACT FROM AUTHOR]

Abstract Silver doped indium sulphide thin films (In 2 S 3 :Ag) were deposited by spray pyrolysis technique on glass substrates at temperature 350 °C. The films were prepared by varying the Ag:In ratio from 0% to 8%. The effect of silver concentration on structural and optical properties of In 2 S 3 :Ag thin films have been studied in detail using X-ray diffraction (XRD) and ultra violet, visible and near infra red (UV–Vis–NIR) transmittance spectroscopy. The X-ray diffraction analysis showed that the prepared layers are polycrystalline and crystallize in a β-In 2 S 3 cubic structure and the size of the crystallites varies between 16 and 20 nm. UV–Vis–NIR spectroscopy measurements revealed that the optical transmittance of the films exceeds 90% in the visible and near infrared region and also the direct band gap energy of the fabricated thin film samples increases with doping from 2.63 to 2.97 eV. The roughness values evaluated are almost constant for different doping concentration. Highlights • In 2 S 3 :Ag thin films was prepared by spray pyrolysis technique. • β-In 2 S 3 :Ag were polycrystalline in nature exhibiting cubic structure. • Crystallite size varies in the range 16–20 nm. • Band gap energy increases with Ag doping from 2.63 to 2.97 eV. • The roughness surface was evaluated from optical measurements. [ABSTRACT FROM AUTHOR]

Abstract Bulk anisotropic RT 7 /α-Fe(Co)+Nd 2 Fe 14 B/α-Fe (RT 7 denotes Sm(CoFeCuZr) 7 phase) multiphase nanohybrid magnets have been designed and prepared by High-Pressure Thermal Compression (HPTC), using a blend of Nd 9 Fe 85.5 Cu 1.5 B 4 amorphous and SmCo-based amorphous-nanocrytalline powders as precursors. The resulting HPTC magnet is composed of alternating RT 7 /α-Fe(Co) and Nd 2 Fe 14 B/α-Fe nanocomposite layers along the pressure direction. A (00 l) crystallographic texture for the RT 7 and Nd 2 Fe 14 B nanocrystals has been achieved in the RT 7 /α-Fe(Co) and Nd 2 Fe 14 B/α-Fe layers, respectively. The RT 7 /α-Fe(Co) layer comprises elongated RT 7 nanocrystals (8–13 nm in thickness and 13–20 nm in length) and approximately equiaxed α-Fe(Co) nanograins with an average size of ∼13 nm. The Nd 2 Fe 14 B/α-Fe layer consists of lath-shaped Nd 2 Fe 14 B nanograins (15–30 nm in thickness and 30–55 nm in length) and approximately equiaxed α-Fe nanograins with an average size of ∼19 nm. The HPTC magnet exhibits a maximum energy product of 25 MGOe, with a high soft-magnetic fraction of ∼30 wt%, and a low coercivity temperature coefficient of β (RT-250 °C) = −0.28% oC−1. Our work provides an alternative approach to yielding high-performance bulk multiphase nanohybrid magnets. Highlights • Bulk anisotropic multiphase nanohybrid magnets have been fabricated. • The nanohybrid magnet has high soft phase content (∼30 wt%) and fine grain size. • The magnet comprises alternating RT 7 /α-Fe(Co) and Nd 2 Fe 14 B/α-Fe layers. • A (00 l) texture for the RT 7 and Nd 2 Fe 14 B nanocrystals is simultaneously achieved. • The magnet displays a large (BH) max = 25 MGOe and a low β (RT-250 °C) = −0.28% oC−1. [ABSTRACT FROM AUTHOR]

Abstract We report dielectric behavior of uniformly dispersed α-Fe 2 O 3 @SiO 2 core-shell nanospheres prepared by employing solvothermal technique. The α-Fe 2 O 3 @SiO 2 core-shell nanospheres were subjected to Fourier transform infrared spectroscopy, which substantiates the presence of metal iron and silicon functional groups. Powder X-ray diffraction analysis establishes the phase purity and composition. X-ray photoelectron spectroscopy analysis demonstrates the formation of α-Fe 2 O 3 @SiO 2 core-shell nanospheres which is further corroborated by scanning electron microscopy images that authenticates the thickness of the shell is sufficiently larger than the core. A relatively high dielectric permittivity (1100) and low loss factor (1.51) is obtained at 1 KHz (at 40 °C). The material follows positive temperature coefficient of resistance type behavior as evidenced in the impedance analysis. Graphical abstract Image 1 Highlights • Monodispersed α-Fe 2 O 3 @SiO 2 core-shell nanospheres are prepared by solvothermal technique. • Powder X-ray diffraction analysis reveals the phase purity and composition. • XPS analysis demonstrates the formation of α-Fe 2 O 3 @SiO 2 core-shell nanospheres. • SEM images visualize α-Fe 2 O 3 @SiO 2 core-shell structure with dense white core and clear grey shell. • Impedance analysis suggests the positive temperature coefficient of resistance type behavior. [ABSTRACT FROM AUTHOR]

Abstract LiZn 1-x M x NbO 4 (M = Co, Ni) (x = 0–0.06) systems were fabricated by a facile solid-state reaction method. Structure and property relationships of spinel structured LiZn 1-x M x NbO 4 were investigated systematically. Appropriate amount of Co2+ and Ni2+ greatly improved the dielectric loss of LiZnNbO 4 ceramics. While, the dielectric loss deteriorated seriously when the doping content exceeded x = 0.02. The origin of dielectric loss in LiZn 1-x M x NbO 4 ceramics was investigated systematically. Moreover, the theoretical dielectric constant and linear expansion coefficient were calculated on the bases of the crystallographic parameters from XRD refinement. The temperature coefficient of resonant frequency calculated by the P-V theory agreed well with the test values. Due to the small doping content, the change in chemical bonds was negligible. Density became the major factor determining the variation of dielectric constant in LiZnNbO 4 ceramics. At last, excellent microwave dielectric properties were obtained: Ts = 1010 °C, ε r = 15.25, Q f = 107,000 GHz, τ f = −63.3 ppm/°C for LiZn 0.98 Co 0.02 NbO 4 and Ts = 995 °C, ε r = 14.85, Q f = 104,000 GHz, τ f = −61.7 ppm/°C for LiZn 0.98 Ni 0.02 NbO 4. Highlights • Structure and property of spinel structured LiZn 1-x M x NbO 4 are investigated. • The origin of dielectric loss in LiZn 1-x M x NbO 4 ceramics is clarified. • Dielectric constant and linear expansion coefficient are obtained by the P-V theory. • Excellent microwave performance make it a promising candidate for LTCC applications. [ABSTRACT FROM AUTHOR]

Abstract The large volume expansion-contraction and low conductivity of Co 3 O 4 leads to electrode pulverisation, capacity loss and poor cycling stability in the application of a capacitor. Herein, an effective and low cost strategy for microwave plasma chemical vapour deposition (CVD) equipment with a modified household microwave oven was implemented to handle micro-porous Co 3 O 4 powder and get high O vacancy electrode active materials. The results show that the morphology, crystal structure and elemental composition of the sample are strongly affected by H 2 plasma. The capacity of the etched micro-porous Co 3 O 4 powder is about 128 Fg-1 after 4000 cycles, which is 3.5 times larger than that of the origin powder. The performance improvement mechanism of the plasma etch was also confirmed. The results show that microwave plasma etching can effectively improve the performance of Co 3 O 4 capacitor materials due to O vacancy increasing and the ratio of Co2+/Co3+ changing, which will benefit other kinds of oxide semiconductor electrode materials. Graphical abstract Image 1 Highlights • Co 3 O 4 powder was treated by microwave plasma etching. • The effect of treated time on the samples were investigated. • The excellent performance samples can be obtained by microwave plasma etching. • Through sample analysis, the cause of performance improvement was obtained. • Proving the microwave plasma technology is a potential material processing treatment. [ABSTRACT FROM AUTHOR]

Abstract To fabricate white-light-emitting diodes (white LEDs) with high color-rendering index or full light spectrum emission, the discovery of more efficient deep-red emitting phosphor materials is essential. In this paper, we have synthesized a series of Sr 2-2x Eu 2x Si 5 N 8 (0 ≤ x ≤ 1) solid-solution compounds, and have systemically investigated effects of full-range Eu concentration on their luminescence. Their emission band maximum can be largely tuned from 610 to 725 nm by increasing Eu content. Reabsorption at low Eu2+ concentration while both the energy transfer and Stocks shift at high Eu2+ concentration account for this large spectral red-shift. Luminescent thermal quenching performance gets worse with Eu2+ concentration increasing. The compound with x = 0.15 possesses the best crystallinity and the highest luminescence intensity with the peak position around 660 nm, and still maintains 88.5% room-temperature intensity at 400 K, indicating that great potential for the application as a deep-red phosphor. Highlights • A full-range Sr 2-2x Eu 2x Si 5 N 8 (0 ≤ x ≤ 1) solid solution was synthesized. • Largely tunable red emission band from 610 to 725 nm by adjusting Eu content. • High quenching concentration and high thermal quenching temperature for Eu2+ emission. [ABSTRACT FROM AUTHOR]

Abstract Ammonia nitrogen contaminated wastewater poses a great threat on the safety of water resources. In this work, a series of hollow tubular structure TiO 2 /hemp stem biochar carbon (HSC) and TiO 2 -CuO/HSC were successfully fabricated under different calcination temperature and were used as catalysts for the degradation of ammonia nitrogen from aqueous solution. The morphologies and structures of the catalysts were characterized by X-ray diffraction (XRD), the Brunauer-Emmett-Teller (BET) method and UV–vis−DRS spectroscopy (DRS) technique. The effects of the different calcination temperature, the dosage of catalyst, the pH on the ammonia solution, and contact time on the degradation process were investigated. In addition, the comparison of ammonia removal efficiency under sunlight and UV-light were studied, and the degradation mechanism was also discussed. The result indicates that those of as-prepared TiO 2 /HSC and TiO 2 -CuO/HSC show excellent photocatalytic activity. The enhanced photocatalytic activity of the nanocomposites can be attributed to the high specific surface area and the reduction of electron-hole pair recombination because of the introduction of HSC and copper oxide. In addition, the removal efficiency of ammonia reached 99.7% under UV light while degraded about of 60.7% under sunlight with TiO 2 -CuO/HSC. The reusing capability and stability of catalysts were studied, and the results demonstrated that the as-prepared composites showed high stability and excellent recycling performance in aqueous reaction systems. The prepared catalysts are promising for the degradation of ammonia nitrogen from wastewater. Graphical abstract Image 1 Highlights • A novel material was synthesized as hollow tubular structure catalysts. • The catalysts have excellent and fast degradation of ammonia nitrogen in water. • The catalysts still remain a high stability and good repeatability after cycles. [ABSTRACT FROM AUTHOR]

Abstract A dual functional sensor for detecting both UV light and H 2 S gas was fabricated using the hexagonal phase porous In 2 O 3 nanoparticles, which were prepared using the hydrothermal and calcination process. The porous In 2 O 3 nanoparticles with large surface areas and pore volumes could provide plenty of active sites to produce much active oxygen species, which were beneficial for the UV light and H 2 S gas sensing reactions, thus resulting in a good sensing performance. At room temperature, the dual functional sensor based on porous In 2 O 3 nanoparticles exhibited ultra-high responses for sensing both UV light (with a wavelength of 365 nm) and H 2 S gas. As a UV sensor, its response was 12886.0 for a UV power intensity of 1.287 mW/cm2 and its detection limit was 0.013 mW/cm2. As a H 2 S gas sensor, the sensor exhibited an ultra-high response (26268.5–1 ppm H 2 S) and a very low detection limit (1 ppb of H 2 S), and it also have excellent selectivity, reversibility and stability. Graphical abstract Image 1 Highlights • Porous In 2 O 3 nanoparticles with large surface areas and pore volume were prepared. • Dual-function sensor was fabricated using these porous In 2 O 3 to detect UV and H 2 S. • The UV and H 2 S dual-function sensor was operated at room temperature. • The sensor showed ultra-high sensitivity to both UV light and H 2 S gas. • The sensor exhibited super detection limit to both UV light and H 2 S gas. [ABSTRACT FROM AUTHOR]

Abstract Free-standing and translucent nanocomposite films with good flexibility were fabricated using a spin-coating process. BaTiO 3 nanoparticles with an average size of about 50 nm and P(VDF-CTFE) 91/9 mol.% copolymer were used as ceramic fillers and polymer matrix, respectively. Dense and uniform microstructure was obtained due to the good compatibility and homogeneous distribution of BaTiO 3 nanoparticles in P(VDF-CTFE) matrix. It was experimentally found that the dielectric constant increased but the breakdown strength decreased with increasing volume fraction of BaTiO 3. A dielectric constant of about 53 was obtained in the nanocomposite film with 40 vol.% of BaTiO 3 , which was about 4.4 times higher than that of the pure P(VDF-CTFE) film. A discharged energy-storage density of 4.9 J/cm3 was obtained in the nanocomposite film with 35 vol.% of BaTiO 3 under 2000 kV/cm, which was about 2 times higher than that of the pure P(VDF-CTFE) film under the same electric field. Highlights • BaTiO 3 -P(VDF-CTFE) nanocomposite films were fabricated using a simple process. • The nanocomposite films were free-standing, flexible and translucent. • Dense and uniform microstructure of the nanocomposite films was obtained. • The dielectric properties and energy-storage performances were investigated. [ABSTRACT FROM AUTHOR]

Abstract Mesoporous silica (mSiO 2) particles are emerging as one of potential abrasives in high-efficiency and damage-free chemical mechanical planarization (CMP) due to their special mechanical and/or chemical characteristics. In this work, the dendritic meso-silica (D-mSiO 2) shells with tunable pore sizes were uniformly deposited on the solid silica (sSiO 2) core surfaces via a modified biphase stratification approach. As confirmed by FESEM, HRTEM, TEM, and N 2 adsorption-desorption measurements, the obtained spherical sSiO 2 /D-mSiO 2 composites with well-defined core/shell structures presented uniform diameter (ca. 340 nm), high surface area (∼210 m2/g), and large pore volume (∼0.3 cm3/g). The average pore size (3.6–11.6 nm) and shell thickness of D-mSiO 2 could be adjusted by varying hydrophobic solvents in the upper oil phases (1-octadecene, decahydronaphthalene, and n-hexane) and amount of silica source. Furthermore, the influence of the pore size of the sSiO 2 /D-mSiO 2 composites on oxide-CMP performance was investigated in terms of surface quality and material removal rate. In our experiments, the lowest average surface roughness was obtained for the composites with the largest pore size, which might result from their lowest overall hardness and elastic modulus determined by their largest porosity. In addition, the highest removal rate was achieved when the pore size of the composites was smallest. The enlarged surface area might contribute to enhancing the chemical corrosion, and further promoting the tribo-chemical reactivity between abrasive particles and substrate surfaces. Overall, the presented results are expected to provide experimental and theoretical basis for the structure optimization of mSiO 2 -based abrasive particles. Graphical abstract Image 1 Highlights • The dendritic meso-silica composite particles with tunable pore sizes were obtained. • The pore size can be adjusted by varying hydrophobic solvents in the upper oil phases. • The dependency of pore size and CMP performance of composite abrasives was explored. • The composite abrasives with the largest pore size reveal the lowest surface finish. • The composite abrasives with the smallest pore size achieve the highest removal rate. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the self-made MoS 2 nanosheets were attempted to be modified with oleic diethanolamide borate (ODAB) through a simple one-step route. The as-modified MoS 2 nanosheets were confirmed by a series of characterizations. The results showed that the MoS 2 nanosheets could be chemically well capped by ODAB to form C-S bonds. Furthermore, the tribological experimental results indicated that the ODAB-MoS 2 nanosheets as lubricant additives could improve the friction properties of base oil. At the optimal adding content of 0.06 wt%, the average friction coefficient, average wear scar diameter and extreme pressure performance of the ODAB-MoS 2 -based oil were decreased by about 27.9%, 22.9% and 17.4% as compared to base oil, respectively. Finally, the friction mechanism was discussed and proposed. Highlights • The MoS 2 nanosheets were chemically well capped by oleic diethanolamide borate molecules. • The ODAB-MoS 2 nanosheets possessed the better dispersibility and stability. • The ODAB-MoS 2 nanosheets showed better tribological properties. [ABSTRACT FROM AUTHOR]

Abstract Additive manufacturing (AM) is an innovative complex shaping technique with unlimited freedom and flexibility in fabrication. Though the majority of AM processes were focused in polymers, it is later extended to metals and very recently to ceramics. Conventional prototyping of ceramics, especially complex parts proceeds through several iterations of design and fabrication of dies, moulds, fixtures etc. which are cost intensive and also time taking to arrive at the final designs. Often the finished parts also needs machining to achieve the micro-features. 3D printing of ceramics with its inherent advantages simplifies above issues especially for fabrication of prototypes leading to the selection of optimum designs in a very short time. Further, as the same infrastructure is based on the printing of ceramic shapes using software generated virtual images it also results in lower cost. In the present study, unlike generally employed UV or visible curable resins to 3D print the green ceramic parts, a new concept of thermally induced gelation of methyl cellulose is used to retain the shape while printing of the parts. In this process, magnesium aluminate spinel paste formulated with 0.25% by weight of methyl cellulose (MC) having optimized rheology was 3D printed simultaneously exposing to the hot air flow close to the MC gelation temperature. Magnesium aluminate spinel test specimens are also shaped using generally practiced slip casting process for the sake of comparison, as slip casting process is not adaptable to fabricate the parts micro-features 3D printed in the present study. The formed parts by both the techniques were pressureless sintered at 1650 °C. 3D printed spinel specimens have shown comparable density, hardness and flexural strength with respect to the slip cast specimens complemented by fractographic analysis. Highlights • 3D printing of spinel ceramics employing thermal gelation property of methyl cellulose. • Comparison of density and mechanical properties of 3D printed specimens with slip casting. • Properties are at par with slip cast specimens due to optimum paste and printing parameters. [ABSTRACT FROM AUTHOR]

Abstract We report on high-responsivity metal-semiconductor-metal (MSM) structure based ultraviolet (UV) GaN photodetectors fabricated on various GaN nanostructures such as porous nanocolumn network (PNCN), nanowall networks (NWNs), and granular and compact thin films. Different GaN nanostructures were hetero-epitaxially grown on c-sapphire using laser molecular beam epitaxy by tuning the AlN buffer layer growth parameters. High resolution x-ray rocking curve measurements indicate that the crystalline quality of GaN critically depends on the selection of AlN buffer layer growth conditions such as type of ablation target and growth temperature. The porous GaN nanostructures revealed a nearly stress-free wurtzite structure as deduced by Raman spectroscopy measurements. Room temperature photoluminescence spectroscopy showed that the GaN films possess a near band emission (NBE) peak at ∼ 3.39 eV along with a broad yellow luminescence (YL) with maxima at 2.25 eV. For GaN PNCN and NWN structures, the NBE-to-YL emission ratio is more than an order higher compared to the GaN films. The fabricated MSM based UV-detector on GaN PNCN and NWN exhibited a high photo-responsivity of ∼27.72 and 24.8 A/W, respectively, under 2 V applied bias at room temperature. The GaN PNCN and NWN nanostructures with excellent photo-responsivity and optical quality prove to be promising candidates for the fabrication of efficient UV photodetectors due to their continuity in lateral direction, high surface area-to-volume ratio and tailored surfaces. Highlights • Laser molecular beam epitaxy of Porous GaN nanostructures on c-sapphire. • Tuning of shape and size of GaN nanostructures with AlN growth parameters. • Formation of GaN porous nanocolumn network (PNCN) and nanowall network (NWN) structures. • Fabrication of metal-semiconductor-metal based GaN UV photodetectors. • Achievement of a high UV responsivity of 27.72 A/W for GaN PNCN photodetectors. [ABSTRACT FROM AUTHOR]

Abstract Maghemite (γ-Fe 2 O 3) is considered more stable than α-Fe 2 O 3 as an anode material for lithium-ion batteries because it has adequate vacancy sites and lower surface energy. However, the facile synthesis of γ-Fe 2 O 3 is still a technological challenge. In this work, a composite based of γ-Fe 2 O 3 and carbon nanotubes (CNTs) is successfully synthesized by a facile one-step direct current arc-discharge approach. Under an atmosphere of low-pressure air, Fe particles act as catalysts for carbon nanotube growth and are subsequently oxidized in situ to γ-Fe 2 O 3 with a mean diameter of about 10 nm deposited on the carbon nanotubes. The as-synthesized γ-Fe 2 O 3 /CNT composite shows a stable cycling capacity of 1186.8 mAh g−1 after 400 cycles at 200 mA g−1. In addition, the γ-Fe 2 O 3 /CNT composite delivers excellent rate performance of 611.8 mAh g−1 at 4000 mA g−1 and a high reversible capacity of 518.5 mAh g−1 remains after 300 cycles at 4000 mA g−1. The highly stable γ-Fe 2 O 3 particles and highly conductive carbon nanotubes are the key factors that provide the extraordinary performance of the composite. Most importantly, γ-Fe 2 O 3 /CNT composite and the arc-discharge fabrication method hold great potential for further industrial applications in energy storage. Graphical abstract Image 1 Highlights • A γ-Fe 2 O 3 /CNT composite is synthesized for Lithium ion batteries. • Fe particles act as catalysts for CNT growth and are oxidized to γ-Fe 2 O 3 on CNTs. • The composite exhibits stable cycling capability and excellent rate performance. • The direct current arc-discharge fabrication method is facile, low-cost and can be scaled up. [ABSTRACT FROM AUTHOR]

Abstract Gallium-diffused lithium niobate (LiNbO 3) channel optical thin-film was fabricated by diffusion of photolithographically patterned gallium-oxide stripes on a Z-cut congruent LiNbO 3 substrate. Composition, optical properties of the channel thin-film and gallium diffusion profiles were characterized. The results show that the thin-film is in congruent composition environment, confines single-mode ordinary and extraordinary waves with a loss <0.5 dB/cm at 1.5 μm wavelength. The confined mode field follows Gaussian/Hermite-Gaussian profile in the width/depth direction of the channel thin-film, and shows definite anisotropy. The diffused gallium ions follow a sum of two error functions in the width and a Gaussian function in the depth direction of the channel optical thin-film. Two-dimensional gallium concentration and refractive index profiles in the channel thin-film are modeled. [ABSTRACT FROM AUTHOR]

Abstract CNTs/Cu-Ti composites were fabricated successfully by spray pyrolysis, low energy ball milling and subsequent hot pressing (HP). Microstructure and mechanical properties of the composites were characterized by SEM, EDS, HRTEM, XRD, hardness and tensile tests. The results reveal that in situ generated nano-TiC particles, as a transition phase from CNTs to Cu-Ti matrix, which played a "rivet" role in enhancing the interfacial bonding between the CNTs and Cu-Ti matrix is formed in the composites. Consequently, mechanical properties of the CNTs/Cu-Ti composites are enhanced compared with alloy matrix, and an optimal balance between elevated ultimate tensile strength and impressively larger plastic deformation is achieved by adding 0.4 wt% CNTs in the composites. (ultimate tensile strength (UTS) 352 MPa, elongation 28.2%, the UTS is 39% higher than that of the Cu-Ti alloy, and the ductility increased significantly by 62%.) Finally, strengthening and toughening mechanisms are discussed. This study provides new insights into the interface structure and strength-ductility in metal-matrix composites. Highlights • CNTs reinforced Cu-Ti alloy composites were fabricated. • Spray pyrolysis method was used to achieve good dispersion of CNTs. • Dispersed CNTs facilitates the reaction with Ti atoms to form interfacial carbides. • CNTs was mixed in the form of coated nano-sized Cu 2 O particles. • Strength and toughness of the composites were improved simultaneously. [ABSTRACT FROM AUTHOR]

Abstract Graphite flake/Cu composites with Zr element introduced into the matrix were successfully fabricated by vacuum hot pressing. The influence of Zr addition on the phase composition, microstructure and properties were investigated. The results indicate that the bending strength in X-Y plane gradually rises with the Zr content increasing from 0 to 2.0 wt%, nearly doubled from 50 MPa to 95 MPa. The thermal conductivity in X-Y plane initially increases and then decreases, yielding a maximum of 640 W m−1 K−1 at 1.0 wt% Zr. This improvement is ascribed to the formation of carbide interfacial layer at the graphite flake/Cu interface. Due to the simple preparation process and excellent thermal conductivity, the graphite flake/Cu composites with moderate Zr addition can be a highly promising candidate for thermal management materials. Highlights • Graphite flake/Cu composites were fabricated by vacuum hot pressing. • ZrC interfacial layer was formed at the interface. • The bending strength nearly doubled by adding 2 wt% Zr. • A maximum thermal conductivity of 640 W m−1 K−1 was obtained. [ABSTRACT FROM AUTHOR]

Abstract This research employed an in-situ growth method to fabrication of multi-walled nanotubes (MWCNTs)/Fe 3 O 4 electromagnetic absorber. Such a binary material system is featured with good impedance matching behavior and moderate attenuation ability, thus exhibits excellent electromagnetic absorption properties. The results reveal that MWCNTs/Fe 3 O 4 exhibits distinct polarization relaxation phenomenon which inducted by interface polarization. This intensity of interface polarization is tunable by controlling the contact area of Fe 3 O 4 and MWCNTs. Due to the contribution of interface polarization loss behavior, the MWCNTs/Fe 3 O 4 sample achieves a wide band electromagnetic absorption property which the frequency region with RL < −10 dB can covers 5.7 GHz at 1.5 mm. The method of utilizing interface strategy to boost dielectric loss ability has an efficient way to gain wide band electromagnetic absorber. Graphical abstract Image 1 Highlights • MWCNTs/Fe 3 O 4 shows dual magnetic/dielectric loss ability. • The weight ratio of MWCNTs/Fe 3 O 4 is tunable. • The effective frequency of MWCNTs/Fe 3 O 4 was up to 5.7 GHz. [ABSTRACT FROM AUTHOR]

Abstract Copper chemical mechanical planarization (Cu-CMP) is an essential procedure for the fabrication of integrated circuits (IC). The corrosion inhibitors in the Cu-CMP slurry could balance the over etching from the corrosion reagents to facilitate the global planarization of the copper layers. However, the normally used Cu-CMP inhibitor 1-benzotriazole (BTA) was toxic for the long time usage. In this paper, the biocompatible polyvinyl pyrrolidone (PVP) was proposed to substitute the BTA in the Cu-CMP. With an integrated electrochemical test, including the Tafel polarization, electrochemical impedance spectra (EIS), and the electrochemical noise (EN), it was found that the PVP could possess a good inhibition effect comparable to BTA, which opened up a promising way for the design of biocompatible inhibitors in the Cu-CMP. Highlights • An integrated electrochemical method was used to analyze Cu-CMP slurry. • PVP was found to be an alternative inhibitor. • Modified equivalent circuit modes were established for PVP and BTA film on Cu. • Physical absorption mode was specified for PVP inhibitor film. [ABSTRACT FROM AUTHOR]

Abstract Long-striped Laves phases are considered to be crack sources in laser repaired Inconel 718 during stress rupture test. In order to obtain fine Laves phases, Nd:YAG pulse laser is used to fabricate Inconel 718 superalloy on a wrought Inconel 718 substrate in this study. The microstructures and stress rupture properties of pulse laser repaired Inconel 718 superalloy after DA treatment (720 °C × 8 h/furnace cooling at 50 °C/h to 620 °C × 8 h/air cooling) and 900STA treatment (900 °C × 20 min/air cooling+720 °C × 8 h/furnace cooling at 50 °C/h to 620 °C × 8 h/air cooling) are investigated by using SEM and TEM. The results shows that granular Laves phases can be obtained when pulse laser is used. The formation of granular Laves phase is related to high cooling rate (G·R) and low ratio of temperature gradient to growth rate (G/R). The critical values of G·R and G/R are 104 and 107, respectively. After 900STA treatment, δ phase precipitates around the granular Laves phases. But there is no δ phases existing in the DA samples. The surrounding δ phases can induce stress concentration, resulting in that the elongation of the 900STA samples is worse than that of the DA samples. However, the regions denuded in Nb element around the δ phases can delay the formation of the vacancies, which leads to that the stress rupture life of the 900STA samples is better than that of the DA samples. Graphical abstract Image 1 Highlights • The deformation behaviors of Laves phase under different loads have been analyzed. • The selection map of Laves phase morphology has been established. • The effects of granular Laves and the surrounding δ phase have been investigated. [ABSTRACT FROM AUTHOR]

Abstract A study on 0.8BaTi 4 O 9 -0.2BaZn 2 Ti 4 O 11 (BZT) filled and glassfiber (GF) reinforced polytetrafluoroethylene (PTFE) was described. The content of GF was 4 wt. %, and the BZT content varied from 26 wt. % to 66 wt. %. BZT complex phase powder was prepared by one synthetic route and modified using perfluorooctyltriethoxysilane (F8261). The microstructure, thermal properties, dielectric properties and temperature coefficient of dielectric constant of the composites were investigated in detail. The results revealed that BZT/GF/PTFE composites hold outstanding dielectric properties and stable thermal properties. Moreover, the specimens exhibited strong hydrophobicity due to the modification of filler using F8261. The BZT/GF filled PTFE composites exhibited reliable dielectric constant (ε r = 4.4), acceptable dielectric loss (tan δ = 0.001), low water absorption (0.02%) and a near-zero temperature coefficient of dielectric constant (τ ε = 1.57 ppm/°C) at filler with contents of 4 wt. % GF and 46 wt. % BZT. Highlights • 0.8BaTi 4 O 9 -0.2BaZn 2 Ti 4 O 11 ceramics were prepared by one synthetic process. • The surface of BZT was successfully modified by C 14 H 19 F 13 O 3 Si. • Modified BZT is hydrophobic resulting in low water absorption in composite. • Increasing BZT contents will increase the density and ε r of the composites. [ABSTRACT FROM AUTHOR]

Abstract The effect of entropy on the strengths of the disordered and ordered phases was investigated. Cost effective AlCo x CrFeNi (x = 0, 0.25, 0.5, 0.75, and 1) high-entropy alloys were fabricated reducing Co content. The strength was considerably reduced when the Co content was zero. This was attributed to the low hardness of the A2 phase due to reduced configurational entropy compared with quinary system. On the other hand, the ordered B2 phase showed the opposite tendency. This result shows that the configurational entropy causes opposing effects on disordered and ordered phases, and the importance of considering the effect of entropy on each phase when the number of elements changed, and an alloy is composed of two or more phases, in particular, having BCC structure. Highlights • Effect of Entropy on the mechanical properties of each phase was studied. • Considerably lower YS of the AlCrFeNi HEA is due to the low strength of the A2 matrix. • Configurational entropy causes opposing effects on disordered and ordered phases. [ABSTRACT FROM AUTHOR]

Abstract A forming-free sol-gel derived ZrO x resistive switching random access memory (RRAM) is demonstrated in this paper. The ZrO x layer after annealing at 400 °C in air shows a condensed poly-crystalline structure with a significant reduction in interstitial oxygen content. The ZrO x RRAM exhibits a remarkable memory window of 103 for 500 dc switching cycles. Retention characteristic is examined to confirm the non-volatile property. The carrier conduction and resistive switching mechanisms are explored. The ZrO x RRAMs are detailedly investigated by XRD, XPS, FTIR, and SEM. Highlights • Simplified and low-cost fabrication of a forming-free ZrO x RRAM. • Resistive switching mechanism of sol-gel ZrO x films. • Demonstration of an ZrO x RRAM with an indium ball top electrode. • Effect of post-annealing on sol-gel ZrO x RRAM performance. [ABSTRACT FROM AUTHOR]

Abstract The tungsten alloys reinforced by ZrO 2 were prepared using azeotropic distillation method combined with powder metallurgy method, and then the sintered tungsten alloys were swaged to obtain compact bars. The microstructures of W- x ZrO 2 (x = 0, 0.25, 1.0 and 1.5 wt%) alloys were investigated by means of SEM, XRD and TEM. The results show that ZrO 2 exist as a stable cubic phase in tungsten alloys by adding Y 2 O 3. Fine ZrO 2 particles (500–800 nm) are dispersed in the tungsten matrix, and thus refine the grain size and improve the physical properties and strength of tungsten alloys. With the increase of the ZrO 2 content, the relative density, hardness and compressive strength of tungsten alloys were all increased. The swaged W–1.5 wt%ZrO 2 alloy shows the finest microstructure with an average grain size of 47.18 μm, reducing 34.76% compared with that of pure tungsten. And thus, the swaged W–1.5 wt%ZrO 2 alloy achieves the highest compressive strength (1941.3 MPa) and failure strain (23.1%) at the same time, increasing 23.27% and 22.37%, respectively, compared with that of pure tungsten. Highlights • W-ZrO 2 alloys were prepared by azeotropic distillation and powder metallurgy process. • c-ZrO 2 particles (500–800 nm) were obtained and evenly distributed in W matrix. • ZrO 2 refined tungsten grain and improved strength and plasticity simultaneously. • Compressive strength of W-1.5%ZrO 2 alloys increases 23.27% in comparison with pure W. • Failure strain of W-1.5%ZrO 2 alloys increases 22.37% in comparison with pure W. [ABSTRACT FROM AUTHOR]

Abstract The chromium silicide-based electroconductive composites were fabricated by solid-state sintering of chromium silicide and chromium oxide powders at 1370 °C in argon. The final densified composites were composed of various solid solution and silicide phases (e.g. Cr 3 Si, Cr 5 Si 3) and silica, depending on the starting silicide/oxide volume ratio ranging from 0.67 to 9.0. Major phases were found to be homogeneously distributed within the metastable (cristobalite) and/or amorphous silica grain boundary phase. The controlled oxidation experiments revealed excellent oxidation resistance at 50°-870 °C, where low-level oxidation was observed. The composites all displayed a metallic-type electrical conductivity due to the presence of the Cr 3 Si, Cr 5 Si 3 and CrSi as the major conductive silicide phases. Their electrical conductivities ranged from 42.1 to 213.7 S/cm at 1000 °C. High-temperature annealing of the composites resulted in phase and microstructural changes, which further improved their high-temperature oxidation resistance and electrical transport properties. Highlights • Chromium silicide-based composites were fabricated via solid-state sintering. • Various chromium silicide phases (e.g. Cr 3 Si, Cr 5 Si 3 , Cr 0.91 Si 0.09) were obtained. • Composite and silicide compositions changed with starting silicide/oxide ratio. • Oxidation tests revealed their excellent oxidation resistance at 50°-870 °C. • Their high electrical conductivities ranged from 42.1 to 213.7 S/cm at 1000 °C. [ABSTRACT FROM AUTHOR]

Abstract We report the synthesis of monolayered g-C 3 N 4 from bulk g-C 3 N 4 via ultrasonication where the monolayered g-C 3 N 4 dispersions remained stable for nearly two months due to effective production of ultra-small-sized layered g-C 3 N 4. A g-C 3 N 4 thin film was fabricated with the utilization of as-prepared dispersion. The fabrication method involved spin coating the dispersion followed by drying at low temperatures of ∼150 °C. The photoelectrochemical performance obtained via this research is comparable with those via other methods of deposition, reaching the value of 1.4 μA cm−2 at 1.23 V (vs. RHE). The g-C 3 N 4 maintained its intrinsic n-type properties and was activated under positive applied bias with minimum amount of dark current. The selection of pure methanol as disperser not only yielded excellent spreadability of the dispersion on substrate but also quickened the drying time. The developed method in this research provided an effective framework for a surpassingly facile and quick fabrication of monolayered g-C 3 N 4 photoelectrodes. Highlights • G-C 3 N 4 thin films were fabricated by spin-coating technique. • 2D G-C 3 N 4 was prepared by liquid exfoliation in methanol. • Quenched N H bonds were observed for 2D g-C 3 N 4 compared with bulk g-C 3 N 4. • 2D G-C 3 N 4 resulted in more uniform thin films compared with bulk g-C 3 N 4. • The photocurrent of 1.4 μAcm−2 at 1.23 V (vs. RHE) were achieved for 2D g-C 3 N 4. [ABSTRACT FROM AUTHOR]

Abstract The coral-like bismuth coated iron mesh (BCIM) was fabricated via chemical etching, immersion replacement and anneal. The resulting sample exhibited remarkable superhydrophobic/superoleophilic property with water contact angle of 163° and oil contact angle almost 0°. Visually, the water and hexane droplet could separately roll off and penetrate into the BCIM surface. Various oil-water (hexane, benzene, toluene, kerosene, bean oil, chloroform, tetrachloride, and water) separations were performed to investigate the separating performance. The initial separation efficiency of hexane-water reached 98.7% and it could maintain over 96% after 20 runs. The BCIM could also act as a scavenger to eliminate the floating or underwater oil. Moreover, it exhibited marvel buoyancy, desired stability and wear resistance. Graphical abstract Image 1 Highlights • Bismuth coated superhydrophobic/superoleophilic iron mesh was fabricated. • The as-prepared mesh could work as an efficient oil-water separation filter. • The as-prepared mesh maintains stability in air, water, and oil-water interface. • The as-prepared mesh exhibited excellent recyclability, corrosion and wear resistance. [ABSTRACT FROM AUTHOR]

Abstract Direct evidence for greatly enhanced photocatalytic performance was observed in the photocatalytic purification of organic pollutant by applying tungsten trioxide (WO 3) nanorods on reduced graphene oxide (RGO) sheets. We reported a viable strategy to fabricate WO 3 /RGO composites via an in-situ solvothermal method. In addition, the photocatalytic performance of as-prepared WO 3 and WO 3 /RGO composites were evaluated by monitoring the degradation of methylthionine chloride (MB)-contained wastewater under visible light irradiation, where more than 94.1% photocatalytic degradation efficiency is achieved within 150 min by WG3 under visible light irradiation, being 71.8% higher than that of pure WO 3. The enhanced photocatalytic activity of WO 3 /RGO composite is mainly attributed to the fact that the formation of well-defined WO 3 -RGO interfaces can efficiently restrain the recombination of photogenerated charges. Additionally, the mineralization degree of MB was analyzed by TOC. This work manufactures a promising application of current water-pollution issues owing to its great photocatalytic efficiency and high recyclability. Graphical abstract Image 1 Highlights • One-pot synthesis of WO 3 /RGO composite was presented. • WO 3 /RGO showed 4-fold higher photocatalytic performance than that of pure WO 3. • This improvement was attributed to the well-defined WO 3 -RGO interfaces. • The interface between microstructure and dye is a factor to enhance degradation. [ABSTRACT FROM AUTHOR]

A novel two-step approach, electrochemical deposition in a cobalt sulfate solution followed by hydrothermal treatment in a nickel sulfate solution, is used to fabricate nanofibrous NiCo 2 O 4 on carbon fibers for binder-free supercapacitor electrodes. The obtained NiCo 2 O 4 consists of nanofibers and nanoflakes which are connected with each other to form open nanopores in the active material. The material exhibits excellent pseudocapacitive performance with a specific capacitance as high as 1807 F g -1  at a current density of 1 A g −1 and a rate capability of 75% at 40 A g −1 . The remarkable electrochemical properties are attributed to the porous structure created by the hydrothermal reaction between oxyhydroxide and Ni 2+ ions. Compared to the conventional method based on hydrothermal decomposition of cobalt and nickel nitrates, this approach is more environment-friendly, and when used for preparation of binder-free electrode, it is more effective in confining nanostructred NiCo 2 O 4 growth to a conductive substrate and ensuring good contact between the active material and the substrate. [ABSTRACT FROM AUTHOR]

3D printing is a fast-emerging technology, and a shape is fabricated using layer-by-layer deposition of a material in a bottom-up manufacturing operation. Here a porous nickel/polyaniline nanocages multiscale supercapacitor synthesized using 3D printing technology is fabricated. The porous structure of iron-nickel and polyaniline nanocages can increase the specific surface area which lead to enhance the specific capacitance. 3D printing technology is presented in energy devices to accurately fabricate the delicate structure. [ABSTRACT FROM AUTHOR]

Mechanically alloyed AlCoCrCuFeNi high-entropy alloy (HEA) powders were used as binder to fabricate WC/HEA composites by spark plasma sintering. The effects of sintering temperature, duration time and binder content on microstructures and mechanical properties were studied. Compared with cobalt binder, the HEA binder has an advantage on the inhibition of WC grain growth due to the sluggish diffusion effect, and the average WC grain size decreases with increasing HEA binder content. Furthermore, the fracture toughness of WC/HEA composites firstly increases with increasing Vickers hardness and then decreases. A good comprehensive mechanical property was obtained after sintering at 1250 °C for 5 min with 10 wt.% HEA binder under a sintering pressure of 30 MPa. The Vickers hardness is 1922 HV 30 and the fracture toughness is 10.41 MPa m 1/2 , which are higher than those of commercial WC/Co composites. Therefore, the AlCoCrCuFeNi high-entropy alloy has a potential to be a binder for WC. [ABSTRACT FROM AUTHOR]

As a powder-bed-based additive manufacturing technology, selective laser melting (SLM) offers high-level flexibility and enables efficient fabrication of complex parts. In connection with complex thermal events occurring during dynamic sequential layer-by-layer deposition, the as-built material is usually hierarchical at different length scales and possesses anisotropy at each level. As a result of a moderate heating temperature of the baseplate and high cooling rates involved in the process, the as-built Ti-6Al-4V alloy has an α′ martensite microstructure. Microstructure evolution occurring during post-SLM heat treatment is strongly affected by the stability of the initial acicular martensite. The present study was aimed at developing an optimum post-SLM heat treatment scheme at a temperature below the β transus temperature, based on the understanding of microstructure evolution occurring during subtransus treatment and the resultant mechanical properties of the alloy. It was observed that the growth of the α and β phases during the heat treatment was inhibited by the initial α′ phase. A higher heating temperature could effectively improve microstructure homogeneity on a micrometer-scale to some extent. Heating temperature affected the strength and fracture strain of the alloy far more than cooling rate. A post-SLM heat treatment at a temperature of 850 °C or higher could lead to an improvement of fracture strain to the level of the forged counterpart, accompanied by the losses in yield strength and ultimate compressive strength from the as-built values. Full annealing (i.e., subtransus treatment at a high temperature) was thus recommended to be an appropriate post-SLM heat treatment for Ti-6Al-4V. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO 2 ) with reversible metal-semiconductor transition is one of the most researched smart materials due to its near room-temperature transition at around 68 °C. Coating VO 2 (M) nanoparticles onto substrate is superior to fabrication of VO 2 (M) thin films owing to its advantages on large-scale preparation and flexible shaping. In this study, freeze-drying has been applied in a convenient precipitating and following annealing process of fabricating VO 2 (M) nanoparticles. More importantly, effects of freeze-drying and pre-freezing temperature on phase composition, size distribution and phase-transition temperature of synthesized particles have been systematically researched by varying the pretreatment conditions. It is observed that the application of freeze-drying is crucial to the formation of pure VO 2 (M), meanwhile, phase-transition temperature and size distribution of VO 2 (M) nanoparticles can be effectively reduced with lowered pre-freezing temperatures. Besides, the influence of different annealing temperatures on nanocrystallite size has been investigated, and it has been found that both the crystallinity and particle size increased as the annealing temperature was increased. Finally, the as-fabricated VO 2 (M) particles were coated onto microscopic glass substrate to characterize mid-infrared modulation performance. The coated film (made from sample pre-frozen at −50 °C) exhibits an excellent mid-infrared transmittance change of 23.3% at a fixed wavelength of 4 μm. This work demonstrates the effect of freeze-drying on the fabrication of VO 2 (M) nanoparticles and provides a facile method for large-scale preparation of VO 2 (M) nanoparticles. [ABSTRACT FROM AUTHOR]

Fe-based amorphous/nanocrystalline coatings were fabricated with industrial FeCoCrMoCBY alloy plate on the mild steel surface by laser cladding. The formation, microstructure were investigated with optical microscope (OM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The results indicate that few pore and just only some cracks are formed in all of the coatings. With increase of heat input, some crystal phases of a-Fe, Fe 3 C and Fe 23 C 6 are precipitated gradually in the coating layers, and the microhardness of the coating layers decreases gradually, while the maximum microhardness is up to 1300 Hv near to 5 times high than that of substrate. Though the passive currents of coating layers increase with increase of heat input, all of coating layers exhibit low corrosion current density, passive current density and wide passive region, which means all of coating layers present excellent corrosion resistance, even more superiors than that of 316L stainless steel in NaCl solution. [ABSTRACT FROM AUTHOR]

Titanium substrate surfaces were rendered superoleophobic by forming hierarchical microhorn/nanopore structures using a facile and cost-effective approach: acid etching and anodization followed by fluorination. The conditions of acid etching and anodization were finely optimized to obtain the best re-entrant structure for the superoleophobic surface. A fluorosilane self-assembled monolayer (SAM) coating on the surface significantly lowered the surface energy, and thereby imparted superoleophobicity, without damaging the hierarchical structure. To evaluate the superoleophobicity, surface contact angles and sliding angles of various liquids with different surface tensions were measured. All the tested liquids, including hexadecane (low surface tension, 27.1 mN/m at 25 °C), exhibited contact angles greater than 150° on the fluorinated hierarchical microhorn/nanoporous surfaces. [ABSTRACT FROM AUTHOR]

We demonstrate the fabrication of core-shell SnO x /carbon nanofiber (CNF) composite mats via single-nozzle one-step electrospinning for use as flexible freestanding electrodes in supercapacitors. The freestanding and flexible nature of the composites is essential for their use in lightweight, portable, and foldable electronic devices and eliminates the need for a separate current collector. We fully characterized the structural and morphological properties of the SnO x /CNF mats and optimized the SnO x to CNF precursor ratio. The optimized SnO x /CNF-based symmetric supercapacitor exhibited a capacitance of 289 F·g −1 at a scan rate of 10 mV·s −1 . Moreover, it retained more than 88% of its initial capacitance after 5000 cycles, highlighting the long-term stability of supercapacitors based on these SnO x /CNF mats. [ABSTRACT FROM AUTHOR]

A novel process for preparing carbon nanotubes (CNTs) reinforced magnesium nanocomposites were developed, which combined friction stir processing (FSP) and ultrasonic assisted extrusion. A very good dispersion of CNTs in AZ91D alloy could be observed. It was demonstrated that the strength of Mg nanocomposites was remarkably enhanced. This was contributed to dislocation strengthening mechanism and stress transfer mechanism, not concerned with the grain refinement. Moreover, the composites maintained good ductility. The interfaces between CNTs and Mg matrix were well bonded, and the interfacial reaction product formation of Al 2 MgC 2 was confirmed. A few edge dislocations were observed at CNTs-matrix boundaries by adding carbon nanotubes. [ABSTRACT FROM AUTHOR]