PdPt bimetallic nanotubes were prepared by the self‐assembly of Pt and Pd on Te nanowires at room temperature. The morphologies of the as‐prepared PdPt nanotubes were investigated by scanning electron microscopy and transmission electron microscopy, and the results display a large amount of PdPt bimetallic nanotubes with a diameter of 10–20 nm and a length of several micrometers. The composition and structure of the nanotubes were characterized by X‐ray diffraction, high‐resolution transmission electron microscopy, scanning transmission electron microscopy, and energy spectrum analysis, and the results display uniform compositional distributions of both elements (Pd and Pt). The mechanism of the formation of the nanotube structure was supposed. The electrocatalytic performance of PdPt nanotubes were studied by cyclic voltammetry and chronoamperometry. Electrochemical results show that the as‐prepared PdPt nanotube catalysts have not only high activity but also good stability for ethanol oxidation in alkaline medium. 相似文献
Four cholate-based pyridinium compounds were synthesized and their binding abilities toward unmodified amino acids were investigated by UV spectroscopy and fluorescence emission spectroscopy. Studies revealed that the recognition process involved hydrogen bonding, electrostatic force, and π–π interaction. The receptor 4a was found to recognize l-tryptophan specifically, and the complex was studied by 1H NMR spectroscopy. The receptors 4b and 4c showed very little recognition ability toward l-tryptophan, indicating the important role of the benzyl group at pyridinium ring. 相似文献
This paper presents a Monte Carlo code to get response spectrum of ions for the Neutron Depth Profiling (NDP) technique called Monte Carlo NDP (MC-NDP) that simulates the behavior of ions transmitted through a sample matrix and generates the energy spectrum for a specified detector. The MC-NDP model is based on the Ziegler–Biersack–Littmark Model, but incorporates the advantages of TRIM and CORTEO. The Impulse Approximation method is used to determine the flight length with the indexical interpolation method rather than the Magic algorithm for the scattering angle between ions and nucleus. This makes MC-NDP more efficient and convenient to simulate entire ion histories by a Monte Carlo approach. MC-NDP’s results agree well with both TRIM results and the experimental data. 相似文献
Two hydrophilic conjugated polymers, PmP‐NOH and PmP36F‐NOH, with polar diethanolamine on the side chains and main chain structures of poly(meta‐phenylene) and poly(meta‐phenylene‐alt‐3,6‐fluorene), respectively, are successfully synthesized. The films of PmP‐NOH and PmP36F‐NOH show absorption edges at 340 and 343 nm, respectively. The calculated optical bandgaps of the two polymers are 3.65 and 3.62 eV, respectively, the largest ones so far reported for hydrophilic conjugated polymers. PmP‐NOH and PmP36F‐NOH also possess deep‐lying highest occupied molecular orbital levels of −6.19 and −6.15 eV, respectively. Inserting PmP‐NOH and PmP36F‐NOH as a cathode interlayer in inverted polymer solar cells with a PTB7/PC71BM blend as the active layer, high power conversion efficiencies of 8.58% and 8.33%, respectively, are achieved, demonstrating that the two hydrophilic polymers are excellent interlayers for efficient inverted polymer solar cells.
Journal of Solid State Electrochemistry - LiFePO4 cathode material is considered as a competitive material for lithium-ion battery, but its poor electronic and ionic conductivity hinder its further... 相似文献
A novel solid-phase microextraction coating of phosphorous-containing titanium oxide composite was developed using titanium fiber as a support and a titanium source by hydrothermal oxidation in a phosphoric acid solution containing hydrogen peroxide. The morphology of the fiber coatings was controlled by the conditions of the hydrothermal oxidation reaction. The oriented nanofiber coating was employed to extract several types of representative aromatic analytes. The experimental results demonstrated that the as-prepared fiber exhibited excellent extraction efficiency toward polycyclic aromatic hydrocarbons. Combined with high-performance liquid chromatography with ultraviolet detection, main extraction conditions were optimized, including pH, ionic strength, extraction temperature, stirring rate, extraction time and desorption time. The established method presented good linearity from 0.05 to 200 μg/L with limit of detection ranging from 0.012 to 0.126 μg/L. This convenient and green procedure was suitable for the selective extraction and determination of typical polycyclic aromatic hydrocarbons in environmental water samples. The relative recoveries of 85.8–112% were obtained for the determination of target polycyclic aromatic hydrocarbons in water samples spiked with 5.0 and 15.0 μg/L. Moreover, the as-prepared fiber showed at least 210 extraction/desorption cycles due to its high mechanical and chemical stability. 相似文献
The redox-mediated electrochemical–chemical process, when it involves the redox-targeting reaction with energy materials, has shown intriguing potential for various energy-related applications. This review starts with a brief discussion on the evolution of redox-targeting reactions for high-energy redox-flow batteries and the critical future studies for large-scale energy storage. Then, with spatially decoupled water electrolysis as an example, the merits of redox-targeting reaction by liberating the catalyst from electrode surface are highlighted, followed by an introduction of redox targeting–based thermal-to-electrical conversion. We have also featured various redox-targeting processes in other fields of study, such as electrochromic window, redox catalysis, and spent battery material recycling. Overall, this review attempts to demonstrate the incredible versatility and prospects of redox-targeting process for energy-related applications. 相似文献
We report a 1.8 μm two-section distributed Bragg reflector laser using butt-jointed In Ga As P bulk material as the waveguide core layer. The threshold current is 17 m A and the output power is 8 m W on average. The threshold current, output power, and emitting wavelength dependences on temperature are measured. The obtained wavelength tuning range is 10 nm. This device has potential applications in simultaneous multiple-gas detection. 相似文献
Materials with hydrophilic–oleophobic properties are of relevance due to their application to different fields such as self-cleaning coatings, liquid–liquid separation membranes and functional textiles for different technical applications. In this work, hydrophilic–oleophobic coatings have been deposited on cellulosic materials (filter paper and bleached cotton) by means of plasma assisted polymerization of acrylic acid solutions in water followed by cationic fluorosurfactant complexation. Chemical composition of the coatings on cellulosic materials was characterized by means of FTIR–ATR and XPS whereas their morphology was studied by SEM. Hydrophilic–oleophobic behavior was characterized by means of contact angle and wetting time. Additionally wetting properties of cationic, anionic and non-ionic surfactant solutions on the hydrophilic–oleophobic coatings were used to characterize the polyelectrolyte electrostatic forces upon the functionalized layer. 相似文献
An efficient method for the enantioselective construction of tertiary vinylglycols through a palladium‐catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with formaldehyde was developed. By using a palladium complex generated in situ from [Pd2(dba)3]?CHCl3 and a phosphoramidite ligand as a catalyst under mild reaction conditions, the process allows conversion of racemic 4‐substituted 4‐vinyl‐1,3‐dioxolan‐2‐ones into the corresponding 1,3‐dioxolanes, as methylene acetal protected tertiary vinylglycols, in high yields with good to excellent enantioselectivities. 相似文献