The commercialization of proton exchange membrane fuel cells (PEMFCs) relies on highly active and stable electrocatalysts for oxygen reduction reaction (ORR) in acid media. The most successful catalysts for this react...
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In this study, the sedimentation stability and rheology of a new magnetorheological fluid formulation were experimentally investigated before and after being stored for 24 months, as well as after being milled. The re...
In this study, the sedimentation stability and rheology of a new magnetorheological fluid formulation were experimentally investigated before and after being stored for 24 months, as well as after being milled. The results reveal that, after undergoing 24 months of steady storage, the off-state viscosity and field-induced yield stress of the MR fluid remained constant, and that its flowability and redispersibility were maintained. After being subjected to ball milling for 2 hours at 200 rpm and 300 rpm, the field-induced yield stress was also maintained.
Hierarchical assembly of arc-like fractal nanostructures not only has its unique self-similarity feature for stability enhancement but also possesses the structural advantages of highly exposed surface-active sites fo...
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Hierarchical assembly of arc-like fractal nanostructures not only has its unique self-similarity feature for stability enhancement but also possesses the structural advantages of highly exposed surface-active sites for activity enhancement, remaining a great challenge for high-performance metallic nanocatalyst design. Herein, we report a facile strategy to synthesize a novel arc-like hierarchical fractal structure of PtPd bimetallic nanoparticles (h-PtPd) by using pyridinium-type ionic liquids as the structure-directing agent. Growth mechanisms of the arc-like nanostructured PtPd nanoparticles have been fully studied, and precise control of the particle sizes and pore sizes has been achieved. Due to the structural features, such as size control by self-similarity growth of subunits, structural stability by nanofusion of subunits, and increased numbers of exposed active atoms by the curved homoepitaxial growth, h-PtPd displays outstanding electrocatalytic activity toward oxygen reduction reaction and excellent stability during hydrothermal treatment and catalytic process.
The Weyl semimetal WTe2and MoTe2show great potential in generating large spin currents since they possess topologically-protected spin-polarized states and can carry a very large current density. In addition, the intr...
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Aqueous zinc ion batteries (ZIBs) have recently attracted an increasing attention as an environmental friendliness, low cost and highly potential novel energy storage system. Although vanadium-based materials serve as...
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Aqueous zinc ion batteries (ZIBs) have recently attracted an increasing attention as an environmental friendliness, low cost and highly potential novel energy storage system. Although vanadium-based materials serve as a capable of arousing and holding the attention cathode materials for ZIBs, whereas low conductivity and confusing zinc ion storage mechanisms remain an obstacle. Herein, FeVO 4 ⋅nH 2 [email protected] composite is employed to evaluate zinc ion storage capability as a cathode for the first time in 2 M Zn(TFSI) 2 electrolyte. Benefiting from the large lattice spacing, dual electrochemical activity and fast electron transfer, the composite delivers excellent rate performance and long life cycle (the capacity retained ∼100 mAh g −1 at 1.0 A g −1 after 1000 cycle). In addition, the electrochemical performance of graphene-modified FeVO 4 ⋅nH 2 O is superior to other precursors for comparison. Furthermore, the intercalated/de-intercalated mechanism of zinc ion is distinct from the traditional conversion reaction, which is confirmed by in-situ X-ray diffraction and various ex-situ techniques.
Multilayered TiO2/ATO thin films were prepared by the spin-coating method to evaluate the electronic interactions and the effect of the experimental conditions on optical transparency, electric resistivity and carrier...
Multilayered TiO2/ATO thin films were prepared by the spin-coating method to evaluate the electronic interactions and the effect of the experimental conditions on optical transparency, electric resistivity and carrier density. ATO chemical composition, number of layers and annealing temperature were modified to study their effect on the global properties of the TiO2/ATO system. TiO2/ATO films exhibited an optical transparency as high as 81 % in the visible wavelength and a strong absorption within the UV spectra. Electric resistivity as low as 3.4 × 10−1 Ωcm was measured for TiO2/ATO films. Optical properties were influenced mainly by the presence of upper TiO2 layer and ATO film thickness. The effect of ATO film thickness, composition and annealing temperature on TiO2/ATO transparency and resistivity are discussed.
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