排序方式: 共有32条查询结果,搜索用时 593 毫秒
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部分还原氧化石墨烯/二氧化钛复合材料的水热合成及其光催化活性 总被引:3,自引:0,他引:3
采用水热法以Hummers氧化法制备的氧化石墨和钛酸四丁酯为原料制备了部分还原的氧化石墨烯/二氧化钛(RGO/TiO2)复合光催化剂, 并研究了该复合材料在可见光以及紫外光下对亚甲基蓝的光催化降解活性.结果表明, 通过改变反应温度和氧化石墨加入量可以调控TiO2的晶相组成及其在复合材料中的分散性; 在水热反应过程中氧化石墨烯发生了部分还原; 所制备的RGO/TiO2复合材料的可见光和紫外光催化活性均高于纯TiO2; 部分还原的氧化石墨烯在复合材料中担当载体和电子受体, 同时可以使TiO2的初始吸收边向可见光区域红移, 增强了TiO2在可见光区域的吸收, 能有效提高对目标污染物的吸附性和光催化降解活性. 相似文献
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Fabrication of protective tantalum carbide coatings on carbon fibers using a molten salt method 总被引:1,自引:0,他引:1
Protective tantalum carbide (TaC) coatings were fabricated successfully on carbon fibers in the temperature range of 950-1100 °C using a molten salt method. A salt mixture composed of LiCl-KCl-KF was used as a reaction medium in which the tantalum and the carbon fiber substrates reacted to form the TaC coatings. The structure and morphology of the TaC coatings were characterized by XRD, SEM and EDX analyses. The results show that the reaction temperature and time have significant influence on the thickness, integrity and surface morphology of the TaC coatings. A uniform, adherent and crack-free TaC coating can be obtained by controlling the reaction temperature and time. Thermo-gravimetric analysis indicated that the oxidation resistance of the carbon fibers was improved remarkably by coating them with a high-quality TaC layer. 相似文献
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《Tetrahedron》2019,75(44):130621
An efficient regioselective and operationally simple urea bromination method utilizing PIDA and potassium bromide is reported. This protocol proved to be effective on a broad range of substituted ureas in acetone at room temperature, forming the p-brominated compounds in 44–86% yields. 相似文献
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Wang Zhiming Xu Zhangwei Guan Yunfeng Zhu Hui Yuan Guanming Dong Zhijun Li Xuanke Zhang Qin Cong Ye 《Research on Chemical Intermediates》2022,48(4):1733-1746
Research on Chemical Intermediates - Activated carbon fibers (ACFs), as the third generation of activated carbon materials, are promising adsorbents due to their rich surface functional groups,... 相似文献
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为满足储能领域对于材料兼具高能量密度和高功率密度的需求, 本文旨在将具有特殊孔隙结构的碳化物衍生碳与具有高导电性和高能量存储密度的石墨化碳(球形天然石墨)相复合, 制备得到一种多孔碳化硅衍生碳/球形天然石墨(SiC-CDCs@NG)复合材料. 采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱、N2吸/脱附等方法对材料的组成、结构、形貌、孔结构和比表面积等进行了表征. 结果表明,SiC-CDCs@NG材料具有较大的且可调节的比表面积和微孔体积, 微孔孔径集中在0.5-0.7 nm范围内; 通过改变NG/Si 摩尔比, 可以有效调控CDCs壳和NG核在复合材料中的组成分布、CDCs微孔的体积、孔径分布和比表面积. 相似文献
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《Physica D: Nonlinear Phenomena》1997,107(1):1-16
We introduce a variation of the statistical method archetypal analysis (Cutler and Breiman, 1994) that tracks moving structures, such as traveling waves or solitons, in a data set. By using this method the traveling part of the motion is separated from the stationary (or semi-stationary) pattern. 相似文献
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以450℃低温炭化的各向异性中间相沥青基炭纤维为原料,先通过KOH化学活化方法制备出活性炭纤维(ACFs),再对ACFs进行炭化改性,以提高ACFs的导电率,系统地研究了炭化温度对ACFs微观形貌、结晶度、孔结构和超级电容器性能的影响。结果显示:经过1 200℃炭化处理的ACFs(ACFs~(-1)200)电极具有优异的电化学性能,在0.1 A·g~(-1)电流密度下比容量高达204 F·g~(-1),1 000次循环后电容保持率达到97.0%;且电流增至20 A·g~(-1)时依然具有高比容量(149 F·g~(-1)),表明ACFs~(-1)200电极相比于未炭化的ACFs,其导电率、大电流密度下的比容量、循环保持率均显著提高。 相似文献
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《中国化学快报》2020,31(4):984-987
In this study,two-dimensional V_2CT_x MXene has been prepared by selectively etching Al layers from V_2 AlC MAX phase by NaF+HCl etching at 90℃ for 72 h and its performance as supercapacitor(SC)electrode were tested using simulating seawater as electrolyte.V_2CT_x MXene-based electrodes shows a good capacitance of 181.1 F/g,which is in accordance with the volumetric specific capacitance of 317.8 F/cm3,and with 89.1% capacitance retention even after 5000 cycle.Compared with other MXenes,V_2CT_x have better electrochemical performance as SC electrode.This work provides an innovative strategy to apply V_2CT_x MXene as SC electrode in safety and effective seawater electrolyte. 相似文献