The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Kunfeng Chen - One of the best experts on this subject based on the ideXlab platform.
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room temperature Chemical Transformation route to cuo nanowires toward high performance electrode materials
Journal of Physical Chemistry C, 2013Co-Authors: Kunfeng ChenAbstract:We demonstrated an efficient room-temperature Chemical Transformation route to CuO nanowires (NWs), from irregular particles to NWs coupled with a series of phase changes from CuCl, through Cu2(OH)3Cl, to Cu(OH)2, and finally to CuO. The room-temperature Chemical Transformation of Cu(OH)2 NW can reserve the initial NW morphology and made the synthesized CuO NW more active in electroChemical reactions. As the anode materials for lithium ion battery, these CuO NWs can exhibit a reversible capacity of 696.1 mAh g–1 after 40 cycles at the rate of 100 mA g–1. The high lithium-storage capacity can be ascribed to the unique structure of these CuO NWs with size of ∼10 nm and grain boundaries on the NWs surfaces, which show more active for the initial electroChemical reaction. CuO NWs and intermediate Cu(OH)2 NWs can also be fabricated as pseudocapacitor electrodes; in KOH electrolyte, their specific capacitances are 118 and 114 F g–1 at the current density of 1 A g–1. The present results indicate that the current...
Sunghwan Han - One of the best experts on this subject based on the ideXlab platform.
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a facile room temperature Chemical Transformation approach for binder free thin film formation of ag2te and lithiation delithiation chemistry of the film
Dalton Transactions, 2016Co-Authors: Eunkyung Kim, Dasom Park, Nabeen K Shrestha, Jin Ho Chang, Sunghwan HanAbstract:The present work demonstrates a highly controllable, facile and environmentally friendly aqueous solution based synthetic method for oxide contamination-free Ag2Te thin films on desired substrates at room temperature using ion exchange induced Chemical Transformation of Ag/AgxO thin films. The films before and after Chemical Transformation reaction are characterized using an energy dispersive X-ray analyzer, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, thin film X-ray diffraction technique, high resolution transmission electron microscopy, and the selected area electron diffraction analysis technique. The as-deposited Ag2Te films show a highly crystalline nature even without thermal treatment. Furthermore, the electrochemistry for lithiation/delithiation of the Ag2Te film is studied for exploring its feasibility in the application as an anode material in a Li-ion battery. The experimentally estimated capacity of the Ag2Te electrode for Li storage is found to be about two and half fold larger than the theoretical capacity of the Ag2Te material. This implies that the binder-free Ag2Te film prepared by the current method could find a potential application in the Li-ion or other similar charge storing devices.
Ming Gong - One of the best experts on this subject based on the ideXlab platform.
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a trialkylphosphine driven Chemical Transformation route to ag and bi based chalcogenides
ChemInform, 2015Co-Authors: Shikui Han, Ming GongAbstract:The reaction of trialkylphosphines with a series of nanostructured chalcogenides results in metals and metal-sulfide heterostructures.
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a trialkylphosphine driven Chemical Transformation route to ag and bi based chalcogenides
Journal of the American Chemical Society, 2015Co-Authors: Shikui Han, Ming GongAbstract:From the standpoint of chemistry, the metastable nature of nanocrystals provides us plentiful ground for the research of new nanoscale structural Transformations. Herein, we report a new phenomenon that trialkylphosphine (TAP) can extract the Ag+ and Bi3+ from their nanostructural chalcogenides and reduce them to the zerovalent state. Based on this principle, a trialkylphosphine-driven Chemical Transformation route has been developed for the synthesis of a series of metals and metal-sulfide heterostructures with multiple sulfides as the precursors. Using this reaction principle, Ag, Bi, Ag-Ni3S2, Ag-ZnS, Ag-AgInS2, Ag-Bi, and Bi-Cu7S4 nanostructures can be successively synthesized. These Ag- or Bi-based metal chalcogenide heteronanostructures with interesting optical properties or multifunctionalities could be of special interest for a variety of applications, including high-performance catalysis, biological and biomedical sensing, photovoltaic devices, and a new generation of optoelectronic devices.
Zongqing Bai - One of the best experts on this subject based on the ideXlab platform.
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Chemical Transformation of sodium species during direct liquefaction of a sodium rich zhundong coal under different atmospheres and co 2 gasification of the direct coal liquefaction residue
Fuel, 2018Co-Authors: Zongqing BaiAbstract:Abstract The attractive Zhundong coalfields located in the Northwestern PR China are featured by many high qualities, such as low contents of mineral matters and total sulfur. However, a significant amount of sodium species are also embedded in the Zhundong coals (ZDC), which has been a barrier for efficient utilization of them. In this work, to better understand the detailed behaviors of sodium species and the Transformation mechanisms during direct coal liquefaction (DCL), Chemical Transformation of sodium species in a ZDC under different liquefaction atmospheres was investigated. As gasification of the direct coal liquefaction residue (DCLR) is commonly used to produce syngas that compensates for the cost of DCL, CO 2 gasification reactivity of sodium-rich DCLR was examined as well. The results show that both H 2 and hydrogen-donor solvents are essential for direct liquefaction of ZDC. Under H 2 atmosphere, retention ratios of sodium species in DCLR were all slightly lower than those under N 2 atmosphere. In the meantime, more CO 2 were produced under H 2 atmosphere. As for Transformation of sodium species during DCL, it is suggested to be closely related with the atmosphere, since more exchangeable sodium species were converted under H 2 atmosphere. Additionally, sodium nitrate was found as one of the water-soluble sodium species in ZDC and sodium-containing silicates could be formed at high temperatures. More importantly, the water-soluble sodium species in DCLR are proved to have catalytic effects on CO 2 gasification reactivity of DCLR. Through careful calculations, a quantitative linear equation has been established between the water-soluble sodium species content and the reactivity index, which can be used to finely predict gasification reactivity of DCLR derived from ZDC.
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Chemical Transformation of inherent sodium and calcium species during direct liquefaction of two typical lignites rich in alkali and alkaline earth metals
Fuel, 2017Co-Authors: Jingpei Cao, Xianliang Meng, Ruizhi Chu, Zongqing BaiAbstract:Abstract Lignite, a suitable feedstock for direct coal liquefaction (DCL), is usually rich in sodium and calcium species. To better understand Chemical Transformation of inherent sodium and calcium species during DCL, two lignites rich in sodium and calcium species were liquefied in this work. The results show that both Australia lignite (AU) and Hami lignite (HM) are preferred raw materials for DCL. After DCL, mineral matters were obviously enriched in residues (DCLR). Under all the temperatures, retention ratios of sodium species were lower than those of calcium species. One obvious Transformation of calcium species was reflected in changes of organic-bound calcium species (AS-Ca) and hydrochloric acid-insoluble calcium species (HIS-Ca) in HM. During direct liquefaction of HM, the amount of AS-Ca decreased significantly and the amount of HIS-Ca increased sharply. XRD analyses of low temperature ashes of DCLR confirmed that when temperatures reached above 400 °C, kaoline in HM gradually decomposed and came to react with AS-Ca, which resulted in formation of HIS-Ca. Due to the low ash content, Transformation of calcium species in AU showed unobvious tendency and only CaCO 3 was detected in DCLR.
Ronald T Raines - One of the best experts on this subject based on the ideXlab platform.
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simple Chemical Transformation of lignocellulosic biomass into furans for fuels and Chemicals
Journal of the American Chemical Society, 2009Co-Authors: Joseph B Binder, Ronald T RainesAbstract:Lignocellulosic biomass is a plentiful and renewable resource for fuels and Chemicals. Despite this potential, nearly all renewable fuels and Chemicals are now produced from edible resources, such as starch, sugars, and oils; the challenges imposed by notoriously recalcitrant and heterogeneous lignocellulosic feedstocks have made their production from nonfood biomass inefficient and uneconomical. Here, we report that N,N-dimethylacetamide (DMA) containing lithium chloride (LiCl) is a privileged solvent that enables the synthesis of the renewable platform Chemical 5-hydroxymethylfurfural (HMF) in a single step and unprecedented yield from untreated lignocellulosic biomass, as well as from purified cellulose, glucose, and fructose. The conversion of cellulose into HMF is unabated by the presence of other biomass components, such as lignin and protein. Mechanistic analyses reveal that loosely ion-paired halide ions in DMA-LiCl are critical for the remarkable rapidity (1-5 h) and yield (up to 92%) of this low-temperature (
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simple Chemical Transformation of lignocellulosic biomass into furans for fuels and Chemicals
Journal of the American Chemical Society, 2009Co-Authors: Joseph B Binder, Ronald T RainesAbstract:Lignocellulosic biomass is a plentiful and renewable resource for fuels and Chemicals. Despite this potential, nearly all renewable fuels and Chemicals are now produced from edible resources, such as starch, sugars, and oils; the challenges imposed by notoriously recalcitrant and heterogeneous lignocellulosic feedstocks have made their production from nonfood biomass inefficient and uneconomical. Here, we report that N,N-dimethylacetamide (DMA) containing lithium chloride (LiCl) is a privileged solvent that enables the synthesis of the renewable platform Chemical 5-hydroxymethylfurfural (HMF) in a single step and unprecedented yield from untreated lignocellulosic biomass, as well as from purified cellulose, glucose, and fructose. The conversion of cellulose into HMF is unabated by the presence of other biomass components, such as lignin and protein. Mechanistic analyses reveal that loosely ion-paired halide ions in DMA−LiCl are critical for the remarkable rapidity (1−5 h) and yield (up to 92%) of this low...