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Multicomponent heterogeneous nanomaterials generally have the potential to exhibit excellent electrochemical performance. Herein, Mn-doped Ni(OH) 2 , NiO and C heterogeneous composites are designed and synthesized by using metal-organic frameworks (MOFs) as self-sacrificial templates. The synergistic effect brought by the multicomponent heterogeneous composition effectively improves the charge storage capacity, the two-dimensional nanosheet structure provides a large specific surface area, and the graphitic carbon enhances the electrical conductivity. The Mn-Ni(OH) 2 /NiO@C composite as an electrode material exhibits a specific capacity of 732.1 C g−1 at 1 A g−1. Furthermore, the assembled Mn-Ni(OH) 2 /NiO@C//AC HSC device can output 38.0 Wh kg−1 at a power density of 849.2 W Kg−1, with 82.9% retention after 5000 cycles. This study provides a novel strategy for MOFs as templates to obtain multicomponent energy storage materials. [Display omitted] • Mn-Ni(OH) 2 /NiO@C heterogeneous composites obtained by Ni-MOF as self-sacrificial template. • Mn-Ni(OH) 2 /NiO@C heterogeneous composites exhibits a unique porous nanosheet structure. • The Mn-Ni(OH) 2 /NiO@C electrode possess high specific capacity. • The assembled Mn-Ni(OH) 2 /NiO@C//AC hybrid supercapacitor exhibit excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

Grain boundary engineering (GBE) was carried out on Hastelloy N alloy which is an important structural material used for molten salt reactor. The proportion of low Σ coincidence site lattice (CSL) grain boundaries of the Hastelloy N alloy can be enhanced to more than 70% with the formation of large-size highly-twinned grain-cluster microstructure which was formed through extensive multiple twinning events during recrystallization. The effects of cold deformation amounts and subsequent annealing on the grain boundary character distribution (GBCD) were investigated. The effects of initial grain size and the primary carbide distribution which was affected by the content of silicon on the grain boundary network evolution were discussed. It was determined that the initial grain size and primary carbide distribution will affect the recrystallization kinetics and hence influence the formation of highly twinned grain-cluster microstructure and the GBCD. The particle stimulated nucleation (PSN) caused by the primary carbides has a detrimental effect on the promotion of low Σ CSL grain boundaries. [ABSTRACT FROM AUTHOR]

• Ultra-fast electrochemical in-situ growth of NiCo-based hydroxides on nickel foams. • The in-situ grown NiCo-LDHs comprise rough and porous hierarchical nanosheets. • The Ni 1 Co 2 /NF electrode has a high specific capacity of 3.01 C cm−2 at 1 mA cm−2. • The assembled HSC device has a high energy density of 97.4 μWh cm−2 at 800.5 μW cm−2. • The assembled HSC device retains 85.0% of its initial capacity after 5000 cycles. [Display omitted] Development of electrode materials with high electrochemical charge storage capabilities through cost-effective methods has attracted intensive attention from researchers. Herein, a low-cost and scaled-up method for electrochemical synthesis of monolithic electrodes is presented. Nickel foam (NF) was chemically etched using the transition metal (NiCo-based) nitrate solutions with different ratios of Ni and Co. After being rinsed and dried, the etched NF was used as anode in an alkaline solution and a Pt mesh was utilized as cathode. Shortly after a constant voltage was applied to the two-electrode system, NiCo-based layered double hydroxides (NiCo-LDHs) were found to be self-grown on the NF with an ultra-fast rate. The in situ grown NiCo-LDHs were composed of hierarchical nanosheets with rough and porous surfaces, and had a high specific area. The monolithic Ni 1 Co 2 /NF electrode exhibited the best electrochemical performance with a high specific capacity of 3.01 C cm−2 at 1 mA cm−2. A hybrid supercapacitor was assembled using the Ni 1 Co 2 /NF as positive electrode and activated carbon as negative electrode. It exhibited a high energy density of 97.4 μWh cm−2 at a power density of 800.5 μW cm−2, and retained 85.0% of initial capacity after 5000 cycles. [ABSTRACT FROM AUTHOR]

The high cost and unfavorable catalytic performance for oxygen reduction reaction (ORR) is one of the crucial obstacles that impede widely commercialization of proton-exchange membrane fuel cells (PEMFCs). Herein, we provide a novel, mass-producible ORR catalyst made of low-loading (10 wt%) Pt nanoparticles bound to patchy nitrogen-doped carbon (PNC) with uniformly dispersed FeN 4 sites (Pt/FeN 4 -PNC). The derived catalyst exhibits significantly improved catalytic activity and stability, obtaining a promising mass activity (MA) of 0.94 A mg pt −1 at 0.9 V (vs. RHE) with a negligible decay after 30,000 cycles accelerated durability test (ADT). In the fuel-cell assessment (under H 2 -Air conditions at 80 ℃), the Pt/FeN 4 -PNC and Pt/FeN 4 -PNC-10 g (scaled-up production) achieved peak power densities of 1.13 W cm−2 and 1.14 W cm−2, respectively, and retained 88.5 % and 88.1 % of the initial values after 30,000 voltage cycles (0.60–0.95 V). The patchy structure of PNC substrate guarantees fast electron routes and resistance to corrosion. With the FeN 4 active sites in the PNC substrate, the oxygen molecules are concurrently reduced on the surfaces of the carbon substrate and Pt nanoparticles, thereby causing the ORR reaction zone on the catalyst layer to expand. [Display omitted] ● The patchy structure of the substrate guarantees fast electron routes and resistance to corrosion. ● The FeN 4 active sites in the PNC substrate significantly enhance the intrinsic ORR activity of the catalyst. ● This effective strategy for the rational design of Pt-integrated catalysts can meet the need of industrialization. [ABSTRACT FROM AUTHOR]

Adiabatic foam has been successfully prepared through sintering sodium silicate which is modified by boric acid. The effect of the sintering temperature, boric acid content and modulus of sodium silicate on the thermal conductivity, density, compression strength and microstructure of the adiabatic foam was studied in detail. In the sintering process, B 3+ ion can take the place of the Si 4+ ion by incorporating into the Si–O–Si structure via Si–O–B bridges, increasing the chemical stability of the adiabatic foam. High temperature, low boric acid content and low modulus of sodium silicate can reduce the thermal conductivity, density and compression strength. In order to meet the application of exterior wall thermal insulation, 450–500 °C of the sintering temperature, 18–24 g boric acid per 600 g sodium silicate solution, and 2.5–2.8 modulus of sodium silicate are chosen. The samples with thermal conductivity less than 0.044 W/m·K, density less than 100 kg/m 3 and compression strength more than 0.7 MPa are obtained. [ABSTRACT FROM AUTHOR]

To obtain ideal implant materials, we hot extruded Mg-2.0Zn-0.5Zr-3.0Gd solid-solution alloys, and studied extrusion temperature impacts on materials properties. Fine dynamic recrystallized (DRXed) grains (∼5 μm) and elongated coarse un-dynamic recrystallized (unDRXed) deformed grains turned out at the range of 470–490 °C, but changed to bigger ones (∼8 μm) and abnormal growth (30–40 μm) at 490–510 °C. Precipitated phases consist of rod-like (Mg, Zn) 3 Gd particles and newly precipitated Mg 2 Zn 11 rectangles. The alloy extruded at 490 °C meets all mechanical and anticorrosive requirements for biomaterials, thanks to evenly distributed second phases via the solid solution, and the grain refinements through the hot extrusion. [ABSTRACT FROM AUTHOR]

In this article, we report on a controllable synthesis of superhydrophobic Sb 2 O 3 microcrystals via a solvothermal method assisted with the soluble inorganic Na 2 WO 4 salt. Morphologies of the final products depend on the amount of the OH − ions adsorbed on Sb 2 O 3 nanoplates. By varying the amount of NaOH, the octahedral Sb 2 O 3 can be switched to microcrystals or microspindles. Reaction and formation mechanisms of Sb 2 O 3 were also proposed, which may also benefit synthesis of other metal oxides with controllable morphology. Additionally, after modified by (Heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane, the as-synthesized octahedral Sb 2 O 3 microcrystals and Sb 2 O 3 microspindles show superhydrophobic and excellent anticorrosion properties in acidic and basic circumstances. [ABSTRACT FROM AUTHOR]

Titanium-zirconium-molybdenum (TZM) alloy was fabricated by using powder metallurgy and rolling techniques. Electrochemical corrosion behavior of the alloy was studied quantitatively using potentiodynamic polarization and scanning electron microscope. Effect of different chloride ions concentrations on corrosion resistance and electrochemical corrosion mechanism on TZM alloy was investigated. Results show that pitting corrosion and intergranular corrosion of TZM alloy mainly occurs in sodium chloride solution. Corrosion generates firstly in the form of pitting corrosion around second phase particles and increases with corrosive media Cl − concentration increasing, and then the intergranular corrosion occurs along grain boundaries and defects. Cl − corrosion can effectively destroy the passive film formed on the sample surface. As the Cl − concentration of corrosive media increases, the corrosion rate of TZM alloy increases until 1.0 mol/L and then decreases. TZM alloy exhibits good corrosion resistance when the concentration of Cl − in corrosive media is 0.5 mol/L or 1.5 mol/L. [ABSTRACT FROM AUTHOR]

Electrochemical corrosion behavior of platinum coated (Pt-coated) lanthanum doped titanium-zirconium-molybdenum alloy (La-TZM alloy) was studied in this paper. La-TZM alloy plates were fabricated using powder metallurgy and rolling technique, and platinum was coated on their surfaces by using electroplating. Corrosion behavior of Pt-coated La-TZM alloy samples were investigated in neutral and alkaline medium while the Cl − concentrations keep invariant, which was quantitatively analyzed using potentiodynamic polarization, scanning electron microscope and energy spectrum techniques. Results show that the Pt-coating can improve the corrosion resistance of the La-TZM alloy. Pt-coating on La-TZM alloy can effectively hinder the matrix alloy electrochemical corrosion during different corrosion mediums. In addition, the Pt-coating on La-TZM alloy in a neutral medium is more corrosion resistant than that in an alkaline medium. Pt-coating can effectively hinder the Cl − destroys the corrosion formed on the surface passivation film, OH − and Cl − double erosion promoted La-TZM alloy intergranular corrosion increased during the electrochemical corrosion processes. [ABSTRACT FROM AUTHOR]

Molybdenum powders were high-energy ball milled for 3, 6, 9 and 12 h respectively, using two ball milling methods: (1) dry milled in vacuum and (2) wet milled in mixed solution of ethanol-polyethylene glycol. The effect of high-energy ball milling on relative density of titanium-zirconium-molybdenum (TZM) alloy was investigated. Particle size distribution and calculated proportion in each size range were designed according to the Dinger-Funk model, reaching the dense packing state. The effects of three different kinds of carbon source (graphite, stearic acid (C 18 H 36 O 2 ) and carbon nanotubes (CNTs)) on oxygen content and relative density were analyzed. The effects of carbon source on oxygen content were studied. After high-energy milling, fine molybdenum alloy powder particles and large amounts of dislocations and vacancies are helpful to improve TZM alloy density during solid sintering process. Doping carbon nanotubes (CNTs) into the TZM alloy as carbon source can improve its density and decrease oxygen content, which is more effective than graphite or stearic acid as carbon sources. Higher TZM alloy relative density results in lower oxygen content. [ABSTRACT FROM AUTHOR]

Titanium-Zirconium-Molybdenum alloy and Lanthanum-doped Titanium-Zirconium-Molybdenum alloy were fabricated by powder metallurgy method. The effect of lanthanum in arc erosion of titanium-zirconium-molybdenum alloy was investigated by using SEM, arc erosion test system and analytical balance. Results show that lanthanum-doped Titanium-Zirconium-Molybdenum alloy has a higher strength, density and lower electrical resistivity compared to that of Titanium-Zirconium-Molybdenum alloy. The average of arc energy and the arc time decrease 17.9% and 20.9% respectively because doping lanthanum decreases the arc current by forming reverse current between the contacts. The mass loss decreases 32.5% and erosion area reduces 32.6%. The lanthanum in the cathode has a good ability of electron emission. [ABSTRACT FROM AUTHOR]

Pt coating on La-TZM alloys can effectively hinder the matrix alloy oxygen corrosion during high temperature oxidation processes. Doping powder metallurgy was used to prepare La-TZM alloy plates (doped with lanthanum), and electroplating was utilized to deposit a platinum coating on the plate surface. After high temperature treatment of the Pt-coated La-TZM alloy samples at different times and temperatures, scanning electron microscopy and energy dispersive spectra analysis of the sample surface and cross-sections were performed to observe the microstructure and composition changes. Differential thermal analysis of the Pt-coated La-TZM alloy specimens after high temperature treatment was performed to assess the high temperature oxidation resistance of the coated matrix alloy. The results show that the oxidation resistance of the TZM alloy can be enhanced, expanding its temperature application range. [ABSTRACT FROM AUTHOR]

La-doping titanium-zirconium-molybdenum alloys have good arc erosion resistance performances, but there is no research about the changes during the arc erosion. Arc erosion characteristics of La-doping titanium-zirconium-molybdenum alloys after 5000 operations under direct current 20 V, 15 A and resistive load conditions were investigated using a JF04C test system. The results indicated that the probability distribution and change trend of arc energy and arc time during 5000 operations were similar and the relationship between arc time and arc energy followed exponential function. The change of arc energy with test number was consistent to electrical resistance. Oxide particles, crater and cracks defects were discovered on the surface of La-doping titanium-zirconium-molybdenum alloy. The electrical resistance change is mainly concerned with the surface. [ABSTRACT FROM AUTHOR]

Sm2+ and Sm3+ co-doped SrB 4 O 7 could be utilized in several high-level optical devices and fundamental knowledge about the optical behavior of these materials benefits the development of luminescent applications. Herein, we report luminescence and its vacuum ultraviolet (VUV) excitation spectra in samarium doped SrB 4 O 7. Both, Sm2+ and Sm3+ luminescence centers have been examined and distinguished in the emission and the excitation spectra investigated under synchrotron radiation. The contribution of either Sm2+ or Sm3+ emission lines into the emission spectra heavily depended on the excitation energy, and strong f-f transitions of both Sm2+ and Sm3+ were detected. At 10 K, a broad intrinsic luminescence in the UV range was detected and attributed to the radiative transition of either bound or self-trapped exciton in SrB 4 O 7. The optical behavior, including e.g. inter-configurational f-d transitions of Sm(n+) were elucidated with first-principles calculations. Partial density of states well represents the changes of the electronic states that are related to the samarium doping, which in turn explains the emerging features in excitation spectra. In summary, the obtained results clarify the excitation and emission behavior of samarium doped SrB 4 O 7. • Luminescence and VUV excitation spectra of Sm(n+) ions in SrB 4 O 7 are demonstrated. • First principle calculations of Sm2+ and Sm3+ ions in SrB 4 O 7 are performed. • Energy transfer process from SrB 4 O 7 host lattice to Sm(n+) centers are suggested. • Multiplications of electronic excitations region in SrB 4 O 7 is identified. • The excitation spectrum of self-trapped exciton emission in SrB 4 O 7 is obtained. [ABSTRACT FROM AUTHOR]