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991.
Alkali‐Metal‐Ion‐Functionalized Graphene Oxide as a Superior Anode Material for Sodium‐Ion Batteries
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Fang Wan Yu‐Han Li Dai‐Huo Liu Jin‐Zhi Guo Prof. Hai‐Zhu Sun Prof. Jing‐Ping Zhang Prof. Xing‐Long Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8152-8157
Although graphene oxide (GO) has large interlayer spacing, it is still inappropriate to use it as an anode for sodium‐ion batteries (SIBs) because of the existence of H‐bonding between the layers and ultralow electrical conductivity which impedes the Na+ and e? transformation. To solve these issues, chemical, thermal, and electrochemical procedures are traditionally employed to reduce GO nanosheets. However, these strategies are still unscalable, consume high amounts of energy, and are expensive for practical application. Here, for the first time, we describe the superior Na storage of unreduced GO by a simple and scalable alkali‐metal‐ion (Li+, Na+, K+)‐functionalized process. The various alkali metals ions, connecting with the oxygen on GO, have played different effects on morphology, porosity, degree of disorder, and electrical conductivity, which are crucial for Na‐storage capabilities. Electrochemical tests demonstrated that sodium‐ion‐functionalized GO (GNa) has shown outstanding Na‐storage performance in terms of excellent rate capability and long‐term cycle life (110 mAh g?1 after 600 cycles at 1 A g?1) owing to its high BET area, appropriate mesopore, high degree of disorder, and improved electrical conductivity. Theoretical calculations were performed using the generalized gradient approximation (GGA) to further study the Na‐storage capabilities of functionalized GO. These calculations have indicated that the Na?O bond has the lowest binding energy, which is beneficial to insertion/extraction of the sodium ion, hence the GNa has shown the best Na‐storage properties among all comparatives functionalized by other alkali metal ions. 相似文献
992.
993.
A novel fluorinated triblock copolymer incorporating 2-ethylhexyl methacrylate (EHMA),tert-butyl methacrylate (tBMA) and 1H,1H,2H,2H-perfluorodecyl acrylate (FA) (PEHMA-b-PtBMA-b-PFA) was first synthesized using three successive reversible addition fragmentation chain transfer (RAFT) polymerization and the subsequent hydrolyzing at acidic condition.The as-fabricated triblock copolymer exhibited an interesting morphology evolution from the multi-compartment rod-like structure to spherical structure along with the addition of a selective solution.At the same time,a visible phase separation domain could be seen in the core area due to the existence of fluorocarbon segments.Furthermore,the selfassembly behavior of the triphilic copolymer at different pH was also verified by transmission electron microscopy,as well as the dynamic light scattering.These stimuli-responsive multi-compartment nanostructures may have potential applications in drug delivery. 相似文献
994.
Ferrocene-based phosphine oxides with various substituents at phosphorous atoms were synthesized by Cu-catalyzed reductive coupling of ferrocenyl ketone-derived tosylhydrazones and H-phosphorus oxides. Followed by the reduction of ferrocene-based phosphine oxides, 1-substituted ferrocene-based phosphine ligand 7 and 1,1′-disubstituted ferrocene-based phosphine ligand 9 were obtained. Josiphos type ligand 8 were produced after ortho-lithiation of 7 and trapping with chlorodiphenyl phosphine or chlorodicyclohexylphosphine. 相似文献
995.
Li Huan Sun Li-Ping Feng Qingmao Huo Li-Hua Zhao Hui Bassat Jean-Marc Rougier Aline Fourcade Sébastien Grenier Jean-Claude 《Journal of Solid State Electrochemistry》2017,21(1):273-280
Journal of Solid State Electrochemistry - The electrochemical performance of Pr2NiMnO6 (PNMO)-xCe0.9Gd0.1O1.95 (CGO) (x = 0–40 wt%) composite oxides as... 相似文献
996.
Yuxin Liu Prof. Ping Liu Prof. Dongqing Wu Yanshan Huang Yanping Tang Prof. Yuezeng Su Prof. Fan Zhang Prof. Xinliang Feng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5617-5622
Heteroatom doping is an effective method to adjust the electrochemical behavior of carbonaceous materials. In this work, boron‐doped, carbon‐coated SnO2/graphene hybrids (BCTGs) were fabricated by hydrothermal carbonization of sucrose in the presence of SnO2/graphene nanosheets and phenylboronic acid or boric acid as dopant source and subsequent thermal treatment. Owing to their unique 2D core–shell architecture and B‐doped carbon shells, BCTGs have enhanced conductivity and extra active sites for lithium storage. With phenylboronic acid as B source, the resulting hybrid shows outstanding electrochemical performance as the anode in lithium‐ion batteries with a highly stable capacity of 1165 mA h g?1 at 0.1 A g?1 after 360 cycles and an excellent rate capability of 600 mA h g?1 at 3.2 A g?1, and thus outperforms most of the previously reported SnO2‐based anode materials. 相似文献
997.
998.
Mei Xiao Na Lei Yongliang Zhang Zhenni Huo Dahai Ding Jian Gao 《Journal of carbohydrate chemistry》2013,32(6):370-382
AbstractPer-O-benzylated ethyl 5-N-acetyl-α-thiosialoside 1 was synthesized and its reactivity as a sialyl donor was investigated. It was demonstrated that the reactions of 1 with various primary and secondary alcohol acceptors, including monosaccharides, gave good to excellent yields (53-92%) and acceptable to excellent α-selectivity (α:β?=?2?~?10:1) , showing its promise for application to sialoglycan synthesis. 相似文献
999.
Yanping Chen Claude Marceau Francis Théberge Jacques Dubois 《Optics Communications》2009,282(21):4283-2209
We diagnosed the polarization characteristics of Terahertz emission from a two-color femtosecond laser filament when the polarizations of ω and 2ω beams are orthogonal. We discovered that the THz pulse is elliptically polarized. The generation mechanism could be through four-wave optical rectification inside the filament zone where the inversion symmetry of air is broken. 相似文献
1000.
TieZhang Yan-pingLin R.J.Tait 《计算数学(英文版)》2004,22(1):113-122
A derivative patch interpolating recovery technique is analyzed for the finite element approximation to the second order elliptic boundary value problems in two dimensional case.It is shown that the convergence rate of the recovered gradient admits superc onvergence on the recovered subdomain, and is two order higher than the optimal global convergence rate (ultracovergence) at an internal node point when even order finite element spaces and local uniform meshes are used. 相似文献