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11.
Developing low-cost but efficient hydrogen evolution reaction(HER)electrocatalysts over whole pH values is a significant but daunting task for the large-scale application of electrochemical hydrogen production.Herein,we develop,for the first time,a scalable MOF-assisted strategy for the fabrication and microstructural optimization of multi-shelled hollow N-doped carbon nanosheet arrays with confined Co/CoP heterostructures on carbon cloth(Co/CoP@NC/CC)for boosting HER performances.The key to this strategy is the step-by-step epitaxial growth of unprecedented multilayer ZIF-L arrays on carbon cloth,which are subsequently pyrolyzed and controllably phosphorized to achieve the precise control over the shell number and nanoarchitectures of the Co/CoP@NC/CC.Impressively,the HER performances can be significantly enhanced by increasing hollow shell number,and the optimal triple-shelled hollow Co/CoP@NC/CC exhibits low overpotentials of 86,78 and 145 mV in acidic,alkaline and neutral media to deliver a current density of 10 mA cm-2,respectively,ranking as one of the best Co-based HER electrocatalysts over whole pH values.Further DFT calculations suggest that the Co/CoP heterostructures can effectively boost the cleavage of H–OH to generate protons and optimize the adsorption energy of hydrogen(ΔGH*),which,together with the large electrode/electrolyte interface and accelerated charge/mass transfer of multi-shelled hollow array structure as well as the good conductivity and dispersity,are responsible for the remarkably improved HER performances.This study not only provides a new toolbox for enriching the family of multi-shelled nanoarchitecture materials,but also points out a general and effective route to develop highly efficient self-supported electrode materials for energy-related applications and beyond. 相似文献
12.
《中国化学快报》2019,30(9):1659-1662
The development of efficient methods for the detection of hazardous and toxic elements is extremely important for environmental security and public health. In this work, we developed a facile colorimetric assaying system for Ag+ detection in aqueous solution. Chitosan-stabilized platinum nanoparticles (Ch-PtNPs) were synthesized and severed as an artificial oxidase to catalyze the oxidation of the substrate 3,3′,5,5′-tetramethylbenzidine (TMB) and generate color signal. In the presence of Ag+, due to the strong metallophilic interactions between Ag+ and Pt2+ on the surface of Ch-PtNPs, Ag+ can weaken the affinity to the substrates and inactivate the catalytic activity of Ch-PtNPs, leading to decreased absorbance signal to varying degrees depending on Ag+ amount. Combing the specific binding between Ch-PtNPs and Ag+ with signal amplification procedure based on the Ch-PtNPs-catalyzed TMB oxidation, a sensitive, selective, simple, cost-effective, and rapid detection method for Ag+ can be realized. Ag+ ions in tap and lake waters have been successfully detected. We ensured that the proposed method can be a potential alternative for Ag+ determination in environmental samples. 相似文献
13.
《European Polymer Journal》2006,42(11):2977-2986
Novel organic/inorganic interpenetrating networks composed of polyurethane (PU), poly(methyl methacrylate) (PMMA) and silica generated from tetraethoxysilane (TEOS), were prepared by in situ bulk polymerization. Optically transparent films were successfully synthesized using 3-(trimethoxysilyl)propyl methacrylate (TMSPM) and isocyanatopropyl triethoxysilane (IPTES) as dual coupling agents. An experimental protocol was established to minimize undesirable side-reactions. According to infrared spectroscopic analysis and thermogravimetric studies of the hybrid materials, the degree of silica condensation was unfavorably affected by the presence of the organic components. Consequently, storage modulus (E′) at 25 °C, and hardness of the films decreased with increasing silica content. 相似文献
14.
15.
《Electrochemistry communications》2007,9(4):801-806
This study demonstrates that proper SEI layer on graphite anode is essential in LiNi0.5Mn1.5O4(LNMO)/graphite 5 V lithium-ion batteries. Succinic anhydride (SA) and 1,3-propane sultone (PS) were found to greatly extend cycle life and suppress swelling behavior of LNMO/graphite cells. The benefits of SA and PS were ascribed not only to the stable SEI layer they form on graphite but also to their stability toward the oxidation at high voltage. Using 1 M LiPF6 EC/EMC (1/2, v/v) solutions with SA and PS, LNMO/graphite Al-laminated pouch cell with nominal capacity of 600 mA h exhibited about 80% capacity retention after 100 cycles. This is the first report on the successful LNMO/graphite 5 V LIB to our best knowledge. 相似文献
16.
With the advent of the big data era, information storage and security are becoming increasingly important. However, high capacity information storage and multilevel anti-counterfeiting are typically difficult to achieve simultaneously. To address this challenge, herein, two electrochromic and electrofluorochromic dual-functional polymers with aggregation-induced emission (AIE) characteristics were rationally designed and facilely prepared. Upon applying voltages, the absorption and fluorescence spectra of the AIE polymers can undergo reversible changes, accompanied by variation of their color and emission. By utilizing the controllable characteristics of the polymers, dual-mode display devices were fabricated via a simple spraying technique. More interestingly, a four-dimensional color code device was constructed by adding color change multiplexing to the two-dimensional space, thereby achieving high capacity information storage. Moreover, the color code device can also be applied in the multilevel anti-counterfeiting area. The encrypted information can be dynamically converted under different voltages. Thus, the AIE polymers show great promise for applications in multidimensional information storage and dynamic anti-counterfeiting, and the design strategy may provide a new avenue for advanced information storage and high security technology.By using electrical stimuli-responsive AIE polymers, dual-mode display devices, multidimensional information storage and anti-counterfeiting devices were constructed. 相似文献
17.
Numerical Algorithms - This paper deals with the blow-up behavior of numerical solutions to nonlinear fractional ordinary differential equations with a dissipative term. Based on the positivity... 相似文献
18.
水热法制备高纯超细CeO2-ZrO2复合氧化物 总被引:9,自引:0,他引:9
Superfine composite powders of CeO2-ZrO2 (CZ) and CeO2-ZrO2-La2O3 (CZL) were prepared by hydrothermal method. The effects of pH、temperature and time for hydrothermal process on the performance of the resulting powders were studied. The optimized reaction parameters were on follows: the precursor′s pH≈9.0, hydrothermal temperature of 200 ℃ holding for 2 h. Thermal stable powders with average particle size smaller than 10 nm and specific surface area of 171 m2·g-1 were obtained. A BET specific surface area was still at 44 m2·g-1 after calcination at 1 000 ℃ for 6 hours. 相似文献
19.
挥发性有机物(VOCs)影响车内空气质量和驾乘者的身心健康。自主研发的在线挥发性有机物质谱仪(SPI-MS 2000),实现了有机物分子的单光子电离,产生无碎片的分子离子,可实现秒级响应,仪器的质量分辨率优于800 FWHM,质量精度优于0.02 amu,对甲苯的测定限优于3μg/m^3,且在3~8000μg/m^3范围内有良好的线性关系。将该仪器应用于某客车车内空气的在线检测:在5 s内检测到20多种微克~毫克每立方米量级的有机物。该仪器在车内VOCs现场快速监测方面有广泛的应用前景。 相似文献
20.
Hong-Bing Ji Ting Ting Wang Le-Fu Wang Yan-Xiong Fang 《Reaction Kinetics and Catalysis Letters》2007,90(2):259-266
A reusable solid catalyst, MnFe1.8Cu0.15Ru0.05O4, has been developed as an effective catalyst for the aerobic oxidation of sulfides and sulfoxides to sulfones. The ruthenium
modified spinel catalyst is the first example reported for such reaction under mild condition with molecular oxygen as the
only oxidant. The oxidation reaction proceeded via an electrophilic attack of the oxygen atom of the catalyst on the electron-rich
sulfur atom of the substrate. 相似文献