排序方式: 共有130条查询结果,搜索用时 328 毫秒
51.
Tongbao Wang Lin Liang Runwei Wang Yanqiu Jiang Kaifeng Lin Jianmin Sun 《Adsorption》2012,18(5-6):439-444
Carbon materials such as activated carbons have been used in the field of water and wastewater treatments. However, the lack of mesopore and, particularly, the difficulty in recovering the spent carbon limited their applications. In this work, magnetic mesoporous carbon microspheres were synthesized by impregnating iron oxide precursors in the mesoporous carbon followed by the in situ conversion of the precursors into magnetite nanoparticles. The as-synthesized carbon microspheres with a high surface area of 742?m2/g and large mesopores of ~4.4?nm exhibited an excellent adsorption capacity for aqueous organic pollutants. The superparamagnetic microspheres with a saturation magnetization of 7.15 emu/g can be easily separated from the treated solution by external magnetic field. 相似文献
52.
Xi Fan Junhui Wang Kaifeng Wu Lei Zhang Jian Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1334-1337
Phase isomerism is a common and important phenomenon in inorganic materials, but the molecular isomerism of their nanocluster models is still rare. In this work, we report the first pair of isomeric titanium‐oxo clusters. Through combining pentagonal {Ti(Ti5)} building units in corner‐sharing or edge‐sharing forms, the two obtained Ti20‐oxo clusters take vertical and horizontal core configurations, respectively, which are both functionalized by the same organic ligands. More interestingly, the vertical type Ti20‐oxo core contains an identical {Ti8O14} moiety as anatase, making it the first molecular model of anatase TiO2. As a result, the vertical type cluster exhibits better photocatalytic H2 evolution activity, higher photocurrent response and faster charge transfer to external acceptors than its horizontal isomer. Thus, this work provides a cluster isomer method to understand the structure–property relationship of import titanium oxide materials. 相似文献
53.
Pengfei Wang Yueshuang Mao Lina Li Zhurui Shen Xiao Luo Kaifeng Wu Pengfei An Haitao Wang Lina Su Yi Li Sihui Zhan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11451-11456
A highly efficient Z‐scheme photocatalytic system constructed with 1D CdS and 2D CoS2 exhibited high photocatalytic hydrogen‐evolution activity of 5.54 mmol h?1 g?1 with an apparent quantum efficiency of 10.2 % at 420 nm. More importantly, its interfacial charge migration pathway was unraveled: The electrons are efficiently transferred from CdS to CoS2 through a transition atomic layer connected by Co–S5.8 coordination, thus resulting in more photogenerated carriers participating in surface reactions. Furthermore, the charge‐trapping and charge‐transfer processes were investigated by transient absorption spectroscopy, which gave an estimated charge‐separation yield of approximately 91.5 % and a charge‐separated‐state lifetime of approximately (5.2±0.5) ns in CdS/CoS2. This study elucidates the key role of interfacial atomic layers in heterojunctions and will facilitate the development of more efficient Z‐scheme photocatalytic systems. 相似文献
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55.
XU HongTao WANG XinShou TAO LeiMing & WU SiXin Key Laboratory for Special Functional Materials of Ministry of Education Henan University Kaifeng China 《中国科学:化学》2010,(3)
MCM-41-type mesoporous silica nanospheres(MSN) have been prepared using n-cetyltrimethylammonium bromide(CTAB) as a soft template.The pseudo-moire' rotational pattern inside the MSN results in many interior defects.Hollow mesoporous silica(HMS) spheres were synthesized by solvent extraction of the template from MSN.The morphology and structure of MSN and HMS were studied by TEM,XRD and nitrogen sorption techniques.A model drug,bromocresol green dye,was packed inside different regions of HMS through impregna... 相似文献
56.
合成了含Cd和Zn的离子液,使其提供金属离子,与Na2S反应制备离子液包裹的半导体纳米材料.X射线衍射和透射电子显微镜分析结果显示:在Cd离子液与Na2S反应中,得到的是尺寸在5~6nm、离子液包裹CdS纳米晶,而在Zn的体系中,最终产物为尺寸在1μm左右六方盘形貌的ZnO颗粒.用热力学和结晶动力学详细讨论了造成Cd和Zn体系在反应条件相同时,产物的形貌和结构差别的原因.荧光性质的测试结果表明:该方法制备的ZnO和CdS纳米粒子具有很好的荧光性能. 相似文献
57.
Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO)2CO3) is one of commonly used antibacterial agents against Helicobacter pylori (H. pylori). Different (BiO)2CO3 nanostructures such as cube-like nanoparticles, nanobars and nanoplates, were fabricated from bismuth nitrate via a simple solvothermal method. The nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the solvents and precursors have an influence on the morphologies of (BiO)2CO3 nanostructures. The possible formation mechanism of different (BiO)2CO3 nanostructures fabricated under different conditions was also discussed. 相似文献
58.
Guo Qiang Hu Zhong Quan Zhanga Song Qiang Xiea Wen Long Huangb a Institute of Chemistry & Biology Henan University Kaifeng China b China Pharmaceutical University Nanjing China 《中国化学快报》2010,(6)
<正>Five C3/C3 fluoroquinolone dimers tethered with a fused heterocyclic ring of s-triazolo[2,1-b][1,3,4]thiadiazole derived from antibacterial quinoiones were synthesized and characterized,and their in vitro antitumor activity against L1210,CHO cell lines was evaluated via the respective IC_(50) values. 相似文献
59.
<正>TiO_2 colloid was prepared by the sol-gel method and was bladed on transparent conduction glass to made nanoporous electrode. The impedance performance of TiO_2 electrode was studied at various bias potential.A simplified equivalent circuit was proposed to investigate the charge transport impedance of TiO_2 film and good fitting results were obtained. 相似文献
60.
Jinchang Zhang Min Liu Anfeng Zhang Kaifeng Lin Chunshan Song Xinwen Guo 《Solid State Sciences》2010,12(2):267-273
Mesoporous silica nanoparticles with controlled morphologies including nanococoons, nanorods and nanospheres have been synthesized in water–acetone media at room temperature using cetyltrimethylammonium bromide (CTAB) as the template. The obtained nanoparticles generally show hexagonal-like mesoporous structures with average pore size ranging from 2.7 to 3.3 nm and surface area from 806 to 1055 m2/g, respectively. It was found that the changes in water-to-acetone molar ratios have a dramatic impact on the morphologies of the mesoporous silica with different surface roughness, probably due to the solvent influence on the rate of the hydrolysis of tetraethoxy silane (TEOS) and the polymerization of inorganic species. Interestingly, the morphology of the mesoporous silica products can be controlled in shape from nanococoons to nanorods to nanospheres just by decreasing the water-to-acetone molar ratio from 75 to 30 to 15, respectively. From transmission electron microscopy (TEM) images, it was observed that mesoporous parallel channels run along the short axis in some areas in the nanorods, whereas the radially arranged mesopore channels are present in the nanospheres. Additionally, hydrothermal treatment leads to rougher surfaces while retaining the morphologies and nanostructures of these mesoporous silicas. 相似文献