The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Chuanqi Feng - One of the best experts on this subject based on the ideXlab platform.
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synthesis of molybdenum disulfide mos2 for lithium ion battery applications
Materials Research Bulletin, 2009Co-Authors: Chuanqi Feng, Hua Li, Rong ZengAbstract:This paper reports the use of a rheological phase reaction method for preparing MoS2 Nanoflakes. The characterization by powder X-ray diffraction indicated that MoS2 had been formed. High resolution electron microscopy observation revealed that the as-prepared MoS2 Nanoflakes had started to curve and partly form MoS2 nanotubes. The lithium intercalation/de-intercalation behavior of as-prepared MoS2 Nanoflake electrode was also investigated. It was found that the MoS2 Nanoflake electrode exhibited higher specific capacity, with very high cycling stability, compared to MoS2 nanoparticle electrode. The possible reasons for the high electrochemical performance of the Nanoflakes electrodes are also discussed. The outstanding electrochemical properties of MoS2 Nanoflakes obtained by this method make it possible for MoS2 to be used as a promising anode material.
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synthesis of tungsten disulfide ws2 Nanoflakes for lithium ion battery application
Electrochemistry Communications, 2007Co-Authors: Chuanqi Feng, Lunfeng Huang, Zaiping Guo, Huakun LiuAbstract:Abstract A novel method (a rheological phase reaction) was used to synthesize WS2 Nanoflakes by adding oxalic acid as a reducing reagent. High resolution electron microscopy observations revealed that the as-prepared WS2 Nanoflakes had started to curve and that WS2 nanotubes were partly formed. The lithium intercalation/deintercalation behavior of as-prepared WS2 electrode was also investigated. It was found that the WS2 Nanoflake electrode exhibited higher specific capacity with very good cycling stability compared to WS2 nanotube or nanoparticle electrodes. The reasons for the improved electrochemical performance of the Nanoflake electrodes are also discussed.
Liping Liang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of porous nis Nanoflake arrays by ion exchange reaction from nio and their high performance supercapacitor properties
Materials Letters, 2014Co-Authors: Xiaoyan Yan, Xili Tong, Changwei Gong, Mingang Zhang, Yuming Tian, Yuesheng Cai, Liping LiangAbstract:Abstract Metal sulfides have emerged as a new class of promising active material for supercapacitors. Porous NiS Nanoflake arrays are successfully synthesized by a facile solution-based ion exchange reaction (IER) method based on preformed chemical bath deposition (CBD) derived NiO Nanoflake arrays. NiS Nanoflake arrays preserve the morphology of precursor-NiO Nanoflake arrays and grow vertically to the substrates. As cathode of supercapacitors, NiS Nanoflake arrays exhibit outstanding electrochemical performances with a high specific capacitance of 718 F g −1 at 2 A g −1 and good cycle performance and capacity retention (593 F g −1 after 3000 cycles at 2 A g −1 ).
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synthesis of mesoporous nio Nanoflake array and its enhanced electrochemical performance for supercapacitor application
Journal of Alloys and Compounds, 2014Co-Authors: Xiaoyan Yan, Xili Tong, Jian Wang, Changwei Gong, Mingang Zhang, Liping LiangAbstract:Abstract Highly porous metal oxide Nanoflake arrays are important for developing high-performance electrochemical devices. Herein, mesoporous NiO Nanoflake arrays have been successfully prepared by a facile hydrothermal synthesis method. Except for the mesoporous walls, the NiO Nanoflakes are interconnected with each other to form macroporous structure. This porous structured NiO Nanoflake arrays possess a high specific surface area of ∼185 m 2 g −1 . The supercapacitor performance of the mesoporous NiO Nanoflake arrays is fully characterized. The mesoporous NiO Nanoflake arrays exhibit weaker polarization, higher specific capacitance and better rate capability than the common NiO Nanoflake arrays. The mesoporous NiO Nanoflake arrays deliver a specific capacitance of 400 F g −1 at 2 A g −1 and 339 F g −1 at 40 A g −1 , respectively, higher than those of the common NiO Nanoflake arrays (287 F g −1 at 2 A g −1 and 179 F g −1 at 40 A g −1 ). The enhanced performance is mainly due to the hierarchical pore system in the mesoporous NiO Nanoflake arrays.
Yujin Chen - One of the best experts on this subject based on the ideXlab platform.
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saturable absorption and the changeover from saturable absorption to reverse saturable absorption of mos2 Nanoflake array films
Journal of Materials Chemistry C, 2014Co-Authors: Qiuyun Ouyang, Kai Zhang, Yujin ChenAbstract:MoS2 Nanoflake array films on different glass substrates were fabricated by an in situ growth method. The nonlinear absorption (NLA) properties of the MoS2 Nanoflake array films were investigated by an open-aperture Z-scan technique. The MoS2 Nanoflake array films exhibited different NLA properties dependent on the input energy. In the case of lower input energy, the films exhibited saturable absorption (SA); however, if the input energy was increased, a changeover from SA to reverse saturable absorption (RSA) was observed. The interesting NLA properties of the films could be attributed to the competition between the ground-state absorption and the excited-state absorption in terms of the energy-level model of MoS2.
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three dimensional hierarchical mos2 Nanoflake array carbon cloth as high performance flexible lithium ion battery anodes
Journal of Materials Chemistry, 2014Co-Authors: Chunling Zhu, Kai Zhang, Yujin Chen, Peng Gao, Piaoping Yang, Qiuyun OuyangAbstract:Flexible lithium-ion batteries are the key to powering a new generation of flexible electronics such as roll-up displays, smart electronics, and wearable devices. Here we report, for the first time, one-step hydrothermal synthesis of a three-dimensional (3D) hierarchical MoS2 Nanoflake array/carbon cloth which shows potential for improving the performance of flexible lithium-ion batteries. Structural characterizations show that the 3D hierarchical MoS2 Nanoflake array/carbon cloth has a similar ordered woven structure to the bare carbon cloth. Each carbon microfiber is covered with many highly ordered 3D MoS2 Nanoflake arrays, and a typical MoS2 Nanoflake, with expanded spacing of the (002) crystal plane, has a uniform width of about 400 nm and a thickness of less than 15 nm. The flexible 3D MoS2 Nanoflake array/carbon cloth as a flexible lithium-ion battery anode has a high reversible capacity of 3.0–3.5 mA h cm−2 at a current density of 0.15 mA cm−2 and outstanding discharging/charging rate stability. Moreover, a fabricated full battery, with commercial LiCoO2 powder and the hierarchical architectures as electrodes, exhibits high flexibility and good electrochemical performance, and can light a commercial red LED even after 50 cycles of bending the full battery.
Jianhong Yi - One of the best experts on this subject based on the ideXlab platform.
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highly anisotropic smco5 Nanoflakes by surfactant assisted ball milling at low temperature
Journal of Magnetism and Magnetic Materials, 2015Co-Authors: Songlin Zhang, Juan Du, Jianhong YiAbstract:Surfactant-assisted ball milling (SABM) has been shown to be a promising method for preparing rare earth-transition metal (RE-TM) Nanoflakes and nanoparticles. In this work, we prepared SmCo5 Nanoflakes by SABM at low temperature, and 2-methyl pentane and trioctylamine were specially selected as solvent and surfactant, respectively, due to their low melting points. The effects of milling temperature on the morphology, microstructure and magnetic performance of SmCo5 Nanoflakes were investigated systematically. Comparing with the samples milled at room temperature, the SmCo5 Nanoflakes prepared at low temperature displayed more homogeneous morphology and lower oxygen content. Remarkably, better crystallinity, better grain alignment and larger remanence ratio were shown in the samples milled at low temperature, which resulted from the distinct microstructure caused by low milling temperature. The differences in structural evolution between the SmCo5 Nanoflakes milled at room temperature and low temperature, including the formation of nanocrystalline, grain boundary sliding, grain rotation, et al., were discussed. It was found that lowering the temperature of SABM was a powerful method for the fabrication of RE-TM Nanoflakes, which showed better hard magnetic properties and lower oxygen content. This was important for the preparation of high-performance sintered magnets, bonded magnets and nanocomposite magnets.
Ying Wang - One of the best experts on this subject based on the ideXlab platform.
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in situ growth moo3 Nanoflake on conjugated polymer an advanced photocatalyst for hydrogen evolution from water solution under solar light
Solar Energy Materials and Solar Cells, 2016Co-Authors: Jun Zhou, Ying WangAbstract:A series of MoO3/PI composite photocatalysts were prepared via a facile in situ solid-thermal approach. Characterization results revealed that the growth of MoO3 Nanoflakes epitaxial (010) face on the surface of PI and introduction of Mo did not change the skeleton structure but enhance the crystallinity of polyimide. The stronger interaction between MoO3 and substrate PI leads to the formation of Mo–N band and Mo5+ species. The measurements for the optical and electronic properties of MoO3/PI composites confirmed that MoO3 Nanoflakes on the surface PI not only induce the absorption of visible light but also suppressed the radiative recombination of charge carriers, which endows the excellent photocatalytic activity of MoO3/PI samples in hydrogen evolution from a CH3OH–H2O solution 9:1 by volume) under solar energy driven. The enhancement of MoO3 Nanoflake for the photocatalytic performance of PI is even more effective than that of Pt at the same loading amount. This work provides a promising choice to substitute noble metal as the cocatalyst on polymer photocatalyst and take a step forward effective utilization of renewable energy.
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synthesis and excellent electromagnetic wave absorption properties of parallel aligned feco c core shell Nanoflake composites
Journal of Materials Chemistry C, 2015Co-Authors: Yongbo Zhang, Peng Wang, Ying Wang, Liang Qiao, Tao WangAbstract:Soft magnetic FeCo@C Nanoflakes were prepared by a simple anoxic annealing technique. The crystalline structure, morphology, and microstructure were systematically characterized. The frequency-dependent electromagnetic and absorbing properties of the Nanoflake paraffin composites were investigated in the 0.1–18 GHz frequency range. The rotational orientation of the composite in an applied magnetic field was performed to make the plane of Nanoflakes parallel to each other. The measurement results showed that both the complex permeability and complex permittivity of the FeCo@C composite were enhanced after orientation. The calculated absorption properties showed that the orientation plays an important role in decreasing the absorber thickness and increasing the absorption performance. For the oriented FeCo@C Nanoflake paraffin composite, the maximum reflection loss of −48.2 dB at 2.1 mm thickness and the effective absorption with RL < −10 dB from 2.5 to 12 GHz at thickness ranging from 1.5 to 4.0 mm were obtained.
