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991.
《Journal of Energy Chemistry》2014,23(4):513-518
Nano-crystalline FeOOH particles(5~10 nm) have been uniformly mixed with electric matrix of single-walled carbon nanotubes(SWNTs)for forming FeOOH/SWNT composite via a facile ultrasonication method. Directly using the FeOOH/SWNT composite(containing 15 wt%SWNTs) as anode material for lithium battery enhances kinetics of the Li+insertion/extraction processes, thereby effectively improving reversible capacity and cycle performance, which delivers a high reversible capacity of 758 mAh g-1under a current density of 400 mA g-1even after 180 cycles, being comparable with previous reports in terms of electrochemical performance for FeOOH anode. The good electrochemical performance should be ascribed to the small particle size and nano-crystalline of FeOOH, as well as the good electronic conductivity of SWNT matrix. 相似文献
992.
Christian Neis Thomas Kradolfer Kaspar Hegetschweiler 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(6):632-637
Single crystals of (1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)lithium(I) diiodide dihydrate, [Li(C6H16N3O3)(C6H15N3O3)]I2·2H2O or [Li(Htaci)(taci)]I2·2H2O (taci is 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol), (I), bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)sodium(I) iodide, [Na(C6H15N3O3)2]I or [Na(taci)2]I, (II), and bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)potassium(I) iodide, [K(C6H15N3O3)2]I or [K(taci)2]I, (III), were grown by diffusion of MeOH into aqueous solutions of the complexes. The structures of the Na and K complexes are isotypic. In all three complexes, the taci ligands adopt a chair conformation with axial hydroxy groups, and the metal cations exhibit exclusive O‐atom coordination. The six O atoms of the resulting MO6 unit define a centrosymmetric trigonal antiprism with approximate D3d symmetry. The interligand O...O distances increase significantly in the order Li < Na < K. The structure of (I) exhibits a complex three‐dimensional network of R—NH2—H...NH2—R, R—O—H...NH2—R and R—O—H...O(H)—H...NH2—R hydrogen bonds. The structures of the Na and K complexes consist of a stack of layers, in which each taci ligand is bonded to three neighbours via pairwise O—H...NH2 interactions between vicinal HO—CH—CH—NH2 groups. 相似文献
993.
《Journal of Energy Chemistry》2014,23(2):207-212
Ultrathin MoS2nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm–2 μm. As anode material for Li-ion batteries, the as-prepared MoS2nanosheets electrodes exhibited a good initial capacity of 1190 mAh g-1and excellent cyclic stability at constant current density of 50 mA g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh g-1. 相似文献
994.
Chiral monolithic absorbent is successfully constructed for the first time by using optically active helical‐substituted polyacetylene and graphene oxide (GO). The preparative strategy is facile and straightforward, in which chiral‐substituted acetylene monomer (Ma), cross‐linker (Mb), and alkynylated GO (Mc) undergo copolymerization to form the desired monolithic absorbent in quantitative yield. The resulting monoliths are characterized by circular dichroism, UV–vis absorption, scanning electron microscopy (SEM), FT‐IR, Raman, energy‐dispersive spectrometer (EDS), X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), XPS, and thermogravimetric analysis (TGA) techniques. The polymer chains derived from Ma form chiral helical structures and thus provide optical activity to the monoliths, while GO sheets contribute to the formation of porous structures. The porous structure enables the monolithic absorbents to demonstrate a large swelling ratio in organic solvents, and more remarkably, the helical polymer chains provide optical activity and further enantio‐differentiating absorption ability. The present study establishes an efficient and versatile methodology for preparing novel functional materials, in particular monolithic chiral materials based on substituted polyacetylene and GO.
995.
Hussein Awada Leila Mezzasalma Sylvie Blanc Delphine Flahaut Christine Dagron‐Lartigau Joël Lyskawa Patrice Woisel Antoine Bousquet Laurent Billon 《Macromolecular rapid communications》2015,36(16):1486-1491
The functionalization of zinc oxide (ZnO) nanoparticles by poly(3‐hexylthiophene) (P3HT) brush is completed by the combination of a mussel inspired biomimetic anchoring group and Huisgen cyclo‐addition “click chemistry.” Herein, the direct coupling of an azide modified catechol derivative with an alkyne end‐functionalized P3HT is described. This macromolecular binding agent is used to access core@corona ZnO@P3HT with a stable and homogeneous conjugated organic corona. Preliminary photoluminescence measurement proves an efficient electron transfer from the donor P3HT to the acceptor ZnO nanoparticles upon grafting, thus demonstrating the potential of such a combination in organic electronics.
996.
997.
近年来,随着社会环保意识的迅速提高以及对可再生能源利用能力的大幅增强,以燃料电池和电解池为代表的电化学技术已经逐渐在能源的存储、转化和利用方面发挥着不可或缺的独特作用.其中,固态氧化物电解池经过多年的发展,在装置成本和工作效率上取得了长足的进步,在储能转化方面具有重要的潜力.与此同时,伴随着《巴黎协定》签订以来各国的“碳中和”路线图逐渐出台,利用相对廉价易得的可再生电能,将二氧化碳(CO2)和甲烷(CH4)等碳-(C1)分子电解转化为高附加值的可再生燃料(如水煤气、乙烯等),对于碳中和目标的实现具有重要的意义.因此,C1分子电化学转化的研究成为了当下重点关注的研究领域,许多重要的研究成果和技术进步在过去几年中不断涌现.固态氧化物电解池作为一种代表性的C1分子电解和转化平台,也日渐引起相关领域研究人员的关注和兴趣.与传统的C1分子催化转化方法相比,基于固态氧化物电解池的电解转化技术具有两个重要优点:高能量转换效率与体系抗中毒能力.这两个特性作为体系稳健性的基石,保障了C1分子转化为可再生燃料的反应过程的长期可持续性.本文首先简要回顾了固态氧化物电解池的前沿技术与发展,并从电解池系统分类、反应体系的特征和反应体系发展的前景与挑战这三个方面,简要介绍了近年来基于固态氧化物电解池体系的C1分子电化学转化的代表性工作.CO2与CH4作为廉价易得的C1分子的代表,其转化因其反应分子惰性及反应过程不可控性而广受研究者关注,本文重点关注了在固态氧化物电解池中CO2,CO2/H2O和CH4三个体系的电化学反应过程和近期研究进展,希望可为相关研究人员未来设计更合适的催化剂和构建更优的电解池结构提供有益的参考.本文还针对目前固态氧化物电解池体系在C1分子转化领域所面临的挑战,提出了未来的一些可能的研究方向,以期助力研究者在不远的将来实现C1分子电解生产可再生燃料的实用化. 相似文献
998.
999.
Kyung Joong Kim 《Surface and interface analysis : SIA》2022,54(4):405-416
Mutual calibration was suggested as a method to determine the absolute thickness of ultrathin oxide films. It was motivated from the large offset values in the reported thicknesses in the Consultative Committee for Amount of Substance (CCQM) pilot study P-38 for the thickness measurement of SiO2 films on Si(100) and Si(111) substrates in 2004. Large offset values from 0.5 to 1.0 nm were reported in the thicknesses by ellipsometry, X-ray reflectometry (XRR), medium-energy ion scattering spectrometry (MEIS), Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), and transmission electron microscopy (TEM). However, the offset value for the thicknesses by X-ray photoelectron spectroscopy (XPS) was close to zero (−0.013 nm). From these results, the mutual calibration method was reported for the thickness measurement of SiO2 films on Si(100) by combination of TEM and XPS. The mutual calibration method has been applied for the thickness measurements of hetero oxide films such as Al2O3 and HfO2. Recently, the effect of surface contamination was reported to be critical to the thickness measurement of HfO2 films by XPS. On the other hand, MEIS was proved to be a powerful zero offset method which is not affected by the surface contamination. As a result, the reference thicknesses in the CCQM pilot study P-190 for the thickness measurement of HfO2 films on Si(100) substrate were determined by mutual calibration method from the average XRR data and MEIS analysis. Conclusively, the thicknesses of ultrathin oxide films can be traceably certified by mutual calibration method and most thickness measurement methods can be calibrated from the certified thicknesses. 相似文献
1000.
锂-氧气电池因其超高的理论比容量而受到科研界的广泛关注, 但其存在较为严重的充放电极化和较差的循环稳定性等问题, 从而极大地限制其商业化进程. 因此设计出有效的正极催化剂是解决锂-氧气电池面临的这些棘手问题的必要手段. 通过对不同充电状态的废旧锂电池正极进行回收制得三种不同锂含量的多元金属氧化物LixMO (x=0.79, 0.30, 0.08; M=Ni/Co/Mn), 并分别用作锂-氧气电池正极催化剂. 系统研究了LixMO材料中锂含量及晶体结构对其电化学性能的影响. 电化学测试结果表明, 与Li0.79MO和Li0.08MO催化剂相比, 基于Li0.30MO为正极催化剂的锂-氧气电池在电流密度100 mA•g–1和限定容量800 mAh•g–1的条件下具有较高的放电比容量(14655.9 mAh•g–1)、较低的充电电压(3.83 V)和较高的能量转换效率(72.2%). 而且该电池体系在充放电循环140圈后充电终止电压仍低于4.3 V. 最终认为制得的Li0.30MO材料具有优异的催化性能归因于其稳定的层状-岩盐相复合结构以及结构中富含的氧化镍相和氧空位之间的协同作用. 这些优点能够促进放电产物的可逆形成与分解, 从而提高锂-氧气电池循环性能. 相似文献