共查询到20条相似文献,搜索用时 140 毫秒
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用一种简单的化学还原方法制备了银纳米粒子包覆的氧化亚铜(Cu2O)纳米复合物。扫描电子显微镜显示Cu2O 为八面体型的纳米粒子,表面光滑,结构对称。包覆的Ag部分占据Cu2O粒子表面。通过比较Ag/Cu2O纳米复合物、Ag溶胶及Cu纳米粒子表面吸附的4-巯基吡啶(4-Mpy)分子表面增强拉曼光谱(SERS)发现,利用此方法得到了Cu2O粒子表面吸附分子的拉曼光谱。银纳米粒子所产生的电磁场增强又增强了吸附在Cu2O上的4-Mpy拉曼信号。这种方法为初步研究Cu2O表面吸附分子性质提供了依据,扩宽了SERS的使用范围,使SERS应用在纳米半导体材料上成为可能。 相似文献
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罗丹明6G(Rhodamine 6G,R6G)是单分子表面增强拉曼光谱(SM-SERS)研究中最常用的探针分子之一,对R6G分子在表面吸附行为的研究有助于了解R6G分子和表面的相互作用. 本文应用电化学和电化学表面增强拉曼光谱技术,研究不同电位下R6G的银电极表面的吸附行为. 结果表明,随着电位负移罗丹明6G在银表面上从垂直吸附转为倾斜吸附,该变化和碱性条件下吸附于金纳米粒子上R6G的吸附构象一致. 这说明,在部分单分子实验中所发现的R6G反常光谱其来源是单个R6G分子在表面吸附取向变化. 本研究对后续详细分析SM-SERS研究中单分子SERS谱峰变化的机制有一定的参考价值. 相似文献
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研究了银溶胶体系表面增强拉曼散射光谱的溶剂效应,发现在不同的溶剂中,银溶胶的聚集状态不同,当胶粒带电荷时,溶剂还能影响分子在胶粒表面的吸附,溶剂通过改变胶粒的聚集状态及分子在胶粒上的吸附这两个因素影响银溶胶体系的SERS光谱。 相似文献
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Effect of silver deposition on tio for photocatalytic oxidation of benzene in the gas phase 总被引:1,自引:0,他引:1
Hisahiro Einaga 《Reaction Kinetics and Catalysis Letters》2006,88(2):357-362
Summary Deposition of Ag on TiO2 surface by photodeposition method improved the photooxidation rate of benzene in air by inhibiting the build-up of intermediate
compounds on the catalyst surface. Although the reaction rate decreased with the increase in benzene concentration, the decrement
of reaction rate became smaller by Ag deposition. The selectivities to CO2 and CO were 95 and 5%, respectively, which were almost independent of Ag loading and benzene conversion. 相似文献
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Gas-Phase Deposited Plasmonic Nanoparticles Supported on 3D-Graphene/Nickel Foam for Highly SERS Detection 下载免费PDF全文
In this work, we proposed a novel three-dimensional (3D) plasmonic nanostructure based on porous graphene/nickel foam (GNF) and gas-phase deposited Ag nanoparticles (NPs).Ag NPs with high density were directly deposited on the surface of 3D GNF by performing a novel cluster beam deposition approach. In comparison with traditional Ag substrate(SiO2/Ag), such hot-spots enriched 3D nanostructure showed extremely high electromag-netic field enhancement under incident light irradiation which could be used as a sensitive chemical sensor based on surface enhanced Raman scattering (SERS). The experimental results demonstrated that the proposed nanostructure showed superior SERS performance in terms of Raman signal reproducibility and sensitivity for the probe molecules. 3D full-wave simulation showed that the enhanced SERS performance in this 3D hierarchical plasmonic nanostructure was mainly obtained from the hot-spots between Ag NPs and the near-field coupling between Ag NPs and GNF sca olds. This work can provide a novel assembled SERS substrate as a SERS-based chemical sensor in practical applications. 相似文献
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Silver nanoparticles supported on ionic‐tagged magnetic hydroxyapatite as a highly efficient and reusable nanocatalyst for hydrogenation of nitroarenes in water 下载免费PDF全文
A novel chemically modified magnetic hydroxyapatite (MHAp) was prepared and used as support and stabilizer for the synthesis of silver nanoparticles. First, 1,4‐diazabicyclo[2.2.2]octane (DABCO) was successfully grafted onto the surface of MHAp, and then silver nanoparticles were homogeneously loaded on mesoporous MHAp‐DABCO (ionic‐tagged MHAp) nanocomposite by in situ chemical reduction of silver nitrate using sodium borohydride. The structure and properties of the resulting MHAp‐DABCO‐Ag nanocomposite were confirmed using various techniques. The catalytic activity of ionic‐tagged MHAp‐Ag nanocatalyst was investigated for the hydrogenation reaction of nitroarenes in aqueous media. The results reveal that the Ag‐containing inorganic–organic nanocomposite is highly efficient for the reduction of a wide range of aromatic nitro compounds under green conditions. The superparamagnetic nature of the nanocatalyst leads to its being readily removed from solution via application of a magnetic field, and it can be easily stored and reused. 相似文献
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Willi Auwärter Dr. Alexander Weber‐Bargioni Susan Brink Dr. Andreas Riemann Dr. Agustin Schiffrin Mario Ruben Dr. Johannes V. Barth Prof. Dr. 《Chemphyschem》2007,8(2):250-254
We report a bottom-up approach for the fabrication of metallo-porphyrin compounds and nanoarchitectures in two dimensions. Scanning tunneling microscopy and tunneling spectroscopy observations elucidate the interaction of highly regular porphyrin layers self-assembled on a Ag(111) surface with iron monomers supplied by an atomic beam. The Fe is shown to be incorporated selectively in the porphyrin macrocycle whereby the template structure is strictly preserved. The immobilization of the molecular reactants allows the identification of single metalation events in a novel reaction scheme. Because the template layers provide extended arrays of reaction sites, superlattices of coordinatively unsaturated and magnetically active metal centers are obtained. This approach offers novel pathways to realize metallo-porphyrin compounds, low-dimensional metal-organic architectures and patterned surfaces which cannot be achieved by conventional means. 相似文献
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Surface Ag+ ions forming complexes with the amino (selenoamino) acids compounds have been studied at a silver nitrate-modified carbon paste electrode (AgNO3/CPE). The carboxyl, amidogen and selenium of selenoamino acids could coordinate with Ag+. The coordinating sites of Ag+-SeCys and Ag+-SeMet on electrode surface have been studied in the range of pH value from 1.0 to 12.0. The coordinating sites of Ag+-SeCys and Ag+-SeMet are due to the different configuration and electronegative charge of amino acids in different acidity. Increase of the coordination number of adsorbed species increases the average lifetime of these species on the surface, and hence causes that stronger bonded molecules more effectively prevent the depletion of the surface layer from the Ag+ ions. The voltammetric signals of Ag+-selenoamino acid and Ag+-sulfur-containing amino acid are stronger than those of Ag+-alanine due to the coordinating sites of AgS and AgSe bonds. Moreover, the adsorption of Ag+-selenoamino acid on electrode surface relates to different acidity. 相似文献
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This article represents a systematical examination of the structures of silver(I) sulfonates incorporating neutral ligands. To survey the influence of the properties of neutral ligands on the structures of silver(I) sulfonates, three kinds of sulfonate anions (L1=1-naphthalenesulfonate, L2=p-toluenesulfonate, and L3=1, 3, 6, 8-pyrenetetrasulfonate) and three kinds of neutral ligands (pyrazine, Pyr, a divergent bidentate ligand; hexamethylenetetramine, hmt, a divergent tetradentate ligand; and beta-picoline, Pic, a monodentate ligand) were selected for study, and five novel silver(I) sulfonates containing neutral ligands have been synthesized: [Ag(L1)(Pyr)].H2O, Ag(L2)(Pyr), Ag4(L3)(Pyr)4(H2O)2, [Ag(L1)(hmt)].H2O, and Ag(L1)(Pic)2. The crystal structures have been determined by single-crystal X-ray diffraction, and these compounds show a variety of structures with different dimensionalities. Moreover, the luminescent properties of compounds and are also discussed. 相似文献
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Molecular structure and vibrational frequencies of the novel surface enolic species intermediate on Ag/Al2O3 have been investigated by means of density functional theory (DFT) calculations and in situ infrared spectroscopy. The geometrical structures and vibrational frequencies were obtained at the B3P86 levels of DFT and compared with the corresponding experimental values. Theoretical calculations show that the calculated IR spectra are in good agreement with the experimental spectroscopic results. In addition, the adsorption energy of enolic species on the Ag/Al2O3 catalyst surface was also evaluated. The reaction mechanism from C2H5OH to enolic species on Ag/Al2O3 catalyst was proposed. 相似文献
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纳米Ag2O2-PbO2化学修饰电极对大肠杆菌细胞膜壁和DNA损伤的研究 总被引:4,自引:0,他引:4
制备了一种新型纳米AgO2-PbO2修饰电极,在选定的正电位下,电极表面产生羟基自由基(.OH).通过测定产生的脂质过氧化物和漏出蛋白质的量来研究羟基自由基对大肠杆菌细胞膜壁损伤的情况,并运用电泳和DNA测序的方法对大肠杆菌质粒DNA的损伤及其对序列变化进行了研究. 相似文献
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N. A. Rogozhnikov 《Russian Journal of Electrochemistry》2016,52(1):63-70
The interaction of AgCN molecules and Ag(CN)2?, Ag(CN)32?, Ag(CN)43? ions with the silver surface is studied based on the cluster model of the metal surface by quantum chemistry methods. The geometrical and energy parameters of the interaction of these species with the metal surface are assessed. As regards the strength of their chemical bond with the surface, these compounds form the following series: Ag(CN)2? < Ag(CN)32? < AgCN < Ag(CN)43?. The surface activity of silver-containing species is compared with regard to the solvent effect. It is found that Ag(CN)2? and Ag(CN)32? anions exhibit close adsorbabilities on silver. Molecules AgCN are not accumulated on the surface because of their very low content in solution. The adsorption of Ag(CN)43? is hindered due to a considerable value of degradation energy of this three-charged ion. In the adsorbed state, the ions Ag(CN)2? and Ag(CN)32? represent stable compounds displaying no surface dissociation to yield compounds with the smaller coordination numbers. 相似文献
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Yunjia Wang Xihong Zu Guobin Yi Hongsheng Luo Hailiang Huang Xuliang Song 《中国化学》2016,34(12):1321-1328
In this study, we developed an approach to fabricate novel 1D Ag NWs‐Ag NPs hybrid substrate for enhanced fluorescene detection of protoporphyrin IX (PpIX) based on surface plasmon‐enhanced fluorescence. The Ag NWs‐Ag NPs hybrid was synthesized by combining the hydrothermal method and self‐assembly method with the asisstance of polyvinylpyrrolidone (PVP). When the Ag NWs‐Ag NPs hybrid was deposited on the glass substrate and employed as active substrate to detect PpIX, the fluorescence intensity of PpIX was enhanced greatly due to the coupling effect of localized surface plasmon‐localized surface plasmon (LSP‐LSP) and localized surface plasmon‐surface plasmon propagation (LSP‐SPP) which induced great enhancement of the electromagnetic field. Furthermore, the enhancement effect was approximately linear when the concentration of PpIX was ranged from 1×10?7 mol/L to 2×10?5 mol/L, and the photobleaching phenomenon of PpIX was reduced greatly, indicating that the fabricated Ag NWs‐Ag NPs hybrid substrate had well performance for PpIX imaging. This work provides an effective approach to prepare highly sensitive and stable fluorescence enhancement substrate, and has great potential application in fluorescence imaging. 相似文献