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Nanoscience and Nanotechnology

2008

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Articles 1 - 30 of 103

Full-Text Articles in Engineering

Nanoantenna Array-Induced Fluorescence Enhancement And Reduced Lifetimes, Reuben M. Bakker, V. P. Drachev, Zhengtong Liu, Hsiao-Kuan Yuan, Rasmus H. Pedersen, Alexandra Boltasseva, Jiji Chen, Joseph Irudayaraj, Alexander V. Kildishev, V. M. Shalaev Dec 2008

Nanoantenna Array-Induced Fluorescence Enhancement And Reduced Lifetimes, Reuben M. Bakker, V. P. Drachev, Zhengtong Liu, Hsiao-Kuan Yuan, Rasmus H. Pedersen, Alexandra Boltasseva, Jiji Chen, Joseph Irudayaraj, Alexander V. Kildishev, V. M. Shalaev

Birck and NCN Publications

Enhanced fluorescence is observed from dye molecules interacting with optical nanoantenna arrays. Elliptical gold dimers form individual nanoantennae with tunable plasmon resonances depending upon the geometry of the two particles and the size of the gap between them. A fluorescent dye, Rhodamine 800, is uniformly embedded in a dielectric host that coats the nanoantennae. The nanoantennae act to enhance the dye absorption. In turn, emission from the dye drives the plasmon resonance of the antennae; the nanoantennae act to enhance the fluorescence signal and change the angular distribution of emission. These effects depend upon the overlap of the plasmon resonance …


Atomic-Layer-Deposited Al2o3/Gaas Metal-Oxide-Semiconductor Field-Effect Transistor On Si Substrate Using Aspect Ratio Trapping Technique, Y Q. Wu, M Xu, P. D. Ye, Z Cheng, J Li, J Park, J Hydrick, J Bai, M Carroll, J G. Fiorenza, A Lochtefeld Dec 2008

Atomic-Layer-Deposited Al2o3/Gaas Metal-Oxide-Semiconductor Field-Effect Transistor On Si Substrate Using Aspect Ratio Trapping Technique, Y Q. Wu, M Xu, P. D. Ye, Z Cheng, J Li, J Park, J Hydrick, J Bai, M Carroll, J G. Fiorenza, A Lochtefeld

Birck and NCN Publications

High quality GaAs epilayers grown by metal-organic chemical vapor deposition are demonstrated on a SiO2-patterned silicon substrate using aspect ratio trapping technique, whereby threading dislocations from lattice mismatch are largely reduced via trapping in SiO2 trenches during growth. A depletion-mode metal-oxide-semiconductor field-effect transistor (MOSFET) is demonstrated on a n-doped GaAs channel with atomic-layer deposited Al2O3 as the gate oxide. The 10 mu m gate length transistor has a maximum drain current of 88 mA/mm and a transconductance of 19 mS/mm. The surface mobility estimated from the accumulation drain current has a peak value of similar to 500 cm(2)/Vs, which is …


Transport-Based Dopant Metrology In Advanced Finfets, Gabriel P. Lansbergen, Rajib Rahman, Cameron J. Wellard, Jaap Caro, Nadine Collaert, Serge Biesemans, Gerhard Klimeck, Lloyd C. L. Hollenberg, Sven Rogge Dec 2008

Transport-Based Dopant Metrology In Advanced Finfets, Gabriel P. Lansbergen, Rajib Rahman, Cameron J. Wellard, Jaap Caro, Nadine Collaert, Serge Biesemans, Gerhard Klimeck, Lloyd C. L. Hollenberg, Sven Rogge

Other Nanotechnology Publications

Ultra-scaled FinFET transistors bear unique fingerprint-like device-to-device differences attributed to random single impurities. Through correlation of experimental data with multimillion atom simulations in NEMO 3-D, we can identify the impurity’s chemical species and determine their concentration, local electric field and depth below the Si/SiO2 interface. The ability to model the excited states rather than just the ground states is the critical need. We therefore demonstrate a new approach to atomistic impurity metrology and confirm the assumption of tunneling through individual impurity quantum states.


Full-Band And Atomisic Simulation Of Realistic 40 Nm Inas Hemt, Mathieu Luisier, Neophytos Neophytou, Neerav Kharche, Gerhard Klimeck Dec 2008

Full-Band And Atomisic Simulation Of Realistic 40 Nm Inas Hemt, Mathieu Luisier, Neophytos Neophytou, Neerav Kharche, Gerhard Klimeck

Other Nanotechnology Publications

A realistic 40 nm InAs high electron mobility transistor is studied using a two-dimensional, full-band, and atomistic Schr¨odinger-Poisson solver based on the sp3d5s∗ tightbinding model. Bandstructure non-parabolicity effects, strain, alloy disorder in the InGaAs and InAlAs barriers, as well as band-to-band tunneling in the transistor OFF-state are automatically included through the full-band atomistic model. The source and drain contact extensions are taken into account a posteriori by adding two series resistances to the device channel. The simulated current characteristics are compared to measured data and show a good quantitative agreement.


From Nemo1d And Nemo3d To Omen: Moving Towards Atomistic 3-D Quantum Transport In Nano-Scale Semiconductors, Gerhard Klimeck, Mathieu Luisier Dec 2008

From Nemo1d And Nemo3d To Omen: Moving Towards Atomistic 3-D Quantum Transport In Nano-Scale Semiconductors, Gerhard Klimeck, Mathieu Luisier

Other Nanotechnology Publications

Lessons learned in 15 years of NEMO development starting from quantitative and predictive resonant tunneling diode (RTD) to multi-million atom electronic structure modeling and the path for OMEN are laid out. The recent OMEN capabilities enable realistically large 3D atomistic nano-scale device simulation.


Optical Hyperspace For Plasmons: Dyakonov States In Metamaterials, Zubin Jacob, Evgenii E. Narimanov Dec 2008

Optical Hyperspace For Plasmons: Dyakonov States In Metamaterials, Zubin Jacob, Evgenii E. Narimanov

Birck and NCN Publications

We show that the subdiffraction imaging behavior observed in the magnifying superlens experiment, [Smolyaninov , Science 317, 1699 (2007)] is due to the hyperbolic dispersion of Dyakonov plasmons supported by the device. These states which are a special case of Dyakonov surface waves [Dyakonov, Sov. Phys. JETP 67, 714 (1988)] exist at the interface of a metal and an anisotropic dielectric giving rise to plasmon beams on resonance. Furthermore, we describe how the unique properties of metamaterial Dyakonov plasmons can be tailored for plasmonic devices.


Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu Dec 2008

Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu

Chemical & Biomedical Engineering Faculty Publications

Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm-2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial …


Hydrodynamic Loading Of Microcantilevers Oscillating Near Rigid Walls, Ryan C. Tung, Jana Anirban, Arvind Raman Dec 2008

Hydrodynamic Loading Of Microcantilevers Oscillating Near Rigid Walls, Ryan C. Tung, Jana Anirban, Arvind Raman

Birck and NCN Publications

The vibrations of microcantilevers in atomic force microscopes (AFMs) or radio frequency (RF) switches are strongly influenced by the viscous hydrodynamics of the surrounding fluid in the vicinity of a rigid wall. While prior efforts to model this hydrodynamic loading have focused on squeeze film damping effects at high Knudsen and squeeze numbers, the regimes of low Knudsen and squeeze numbers are also very important for which squeeze film models need to be discarded in favor of unsteady Stokes hydrodynamics. We extend the work of Green and Sader [Phys Fluids 17, 073102 (2005); J. Appl. Phys. 98, 114913 (2005)] and …


Preparation And Optical Transmission Of The Zno Nanorod Array Films, Feng Ye, Jing-Jing Li, Tong-Tao Wang, Yong-Liang Wang, Yun Liu, Xin-Dong Wang Nov 2008

Preparation And Optical Transmission Of The Zno Nanorod Array Films, Feng Ye, Jing-Jing Li, Tong-Tao Wang, Yong-Liang Wang, Yun Liu, Xin-Dong Wang

Journal of Electrochemistry

By using a galvaostatic electrodeposition method in the ZnCl2 solution,the highly oriented ZnO nanorod array films have been successfully prepared on ITO substrate after the pretreatment with ZnO nanoparticles.And they were characterized by scanning electron microscope,X-ray diffraction and transmittance spectra.The results indicated that the ZnO nanorod arrays grew along(001) direction with an orientation perpendicular to the substrate.When the wavelength of incident was over 380 nm,the ZnO nanorod arrays showed high optical transmission of above 95%.Furthermore,the band gap became narrower.


The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong Nov 2008

The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode materials of nanosiged LiFePO4 were prepared by hydrothermal templating synthesis.The grain sizes and electrochemical performance of LiFePO4 were controlled by surfactant.It was shown that the grain sizes varied from less than a hundred to hundreds nanometers by the SEM images.In the charge/discharge tests,the discharge capacities of the sample as a lithium ion battery were achieved to 150 mAh/g at 0.1C,140 mAh/g at 1C,and 126 mAh/g at 2C,with good cycling performance.


Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang Nov 2008

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work.The outer CL was Nafion-free,while the inner CL was Nafion-bonded.The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated.Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL.The polarization curves showed that the output voltage of the …


Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu Nov 2008

Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu

Journal of Electrochemistry

A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10-10 ~ 5.0×10-8 mol/L and 1.0×10-7 ~ 3.0×10-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was 1.0 × 10-11 mol/L.This …


Transformation Optics: Approaching Broadband Electromagnetic Cloaking, Alexander V. Kildishev, W Cai, U K. Chettiar, V. M. Shalaev Nov 2008

Transformation Optics: Approaching Broadband Electromagnetic Cloaking, Alexander V. Kildishev, W Cai, U K. Chettiar, V. M. Shalaev

Birck and NCN Publications

An approach to broadband cloaking of light waves is analysed for a simplified case of a scaling transformation for a general cylindrical coordinate system. The proposed approach requires metamaterials with specifically engineered dispersion. The restriction on the signs of gradients in the dispersion dependencies of the dielectric permittivity and the magnetic permeability for different operational wavelengths is revealed and is shown to cause difficulties unless additional gain-assisted compensation for losses or electromagnetically induced transparency is introduced in the cloaking system.


Solutions In Folded Geometries, And Associated Cloaking Due To Anomalous Resonance, Graeme W. Milton, Nicolae-Alexandru P. Nicorovici, Ross C. Mcphedran, Kirill Cherednichenko, Zubin Jacob Nov 2008

Solutions In Folded Geometries, And Associated Cloaking Due To Anomalous Resonance, Graeme W. Milton, Nicolae-Alexandru P. Nicorovici, Ross C. Mcphedran, Kirill Cherednichenko, Zubin Jacob

Birck and NCN Publications

Solutions for the fields in a coated cylinder where the core radius is bigger than the shell radius are seemingly unphysical, but can be given a physical meaning if one transforms to an equivalent problem by unfolding the geometry. In particular, the unfolded material can act as an impedance matched hyperlens, and as the loss in the lens goes to zero finite collections of polarizable line dipoles lying within a critical region surrounding the hyperlens are shown to be cloaked having vanishingly small dipole moments. This cloaking, which occurs both in the folded geometry and the equivalent unfolded one, is …


Structural Nanocomposites, Yuris A. Dzenis Nov 2008

Structural Nanocomposites, Yuris A. Dzenis

Nebraska Center for Materials and Nanoscience: Faculty Publications

Materials scientists predict that composites made with nanoscale reinforcing materials such as nanotubes, platelets, and nanofibers will have exceptional mechanical properties. However, the results obtained so far are disappointing, particularly when compared to advanced composites reinforced with high-performance continuous fibers (1–4). The reasons include inadequate dispersion and alignment of the nanoreinforcement, low nanoreinforcement volume fraction, and poor bonding and load transfer at interfaces. Intensive work is under way, but the prospect of bulk structural supernanocomposites appears more remote now than it did just a few years ago. However, recent work shows that some applications in reinforcement of small structures may …


Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr Nov 2008

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …


Toward Nanowire Electronics, Joerg Appenzeller, Joachim Knoch, Mikael Bjoerk, Heike Riel, Heinz Schmid, Walter Riess Nov 2008

Toward Nanowire Electronics, Joerg Appenzeller, Joachim Knoch, Mikael Bjoerk, Heike Riel, Heinz Schmid, Walter Riess

Other Nanotechnology Publications

This paper discusses the electronic transport properties of nanowire field-effect transistors (NW-FETs). Four different device concepts are studied in detail: Schottky-barrier NW-FETs with metallic source and drain contacts, conventional-type NW-FETs with doped NW segments as source and drain electrodes, and, finally, two new concepts that enable steep turn-on characteristics, namely, NW impact ionization FETs and tunnel NW-FETs. As it turns out, NW-FETs are, to a large extent, determined by the device geometry, the dimensionality of the electronic transport, and the way of making contacts to the NW. Analytical as well as simulation results are compared with experimental data to explain …


Structures And Energetics Of Silicon Nanotubes From Molecular Dynamics And Density Functional Theory, Amritanshu Palaria, Gerhard Klimeck, Alejandro Strachan Nov 2008

Structures And Energetics Of Silicon Nanotubes From Molecular Dynamics And Density Functional Theory, Amritanshu Palaria, Gerhard Klimeck, Alejandro Strachan

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We use molecular dynamics with a first-principles-based force field and density functional theory to predict the atomic structure, energetics, and elastic properties of Si nanotubes. We find various low-energy and low-symmetry hollow structures with external diameters of about 1 nm. These are the most stable structures in this small-diameter regime reported so far and exhibit properties very different from the bulk. While the cohesive energies of the four most stable nanotubes reported here are similar (from 0.638 to 0.697 eV above bulk Si), they have disparate Young's moduli (from 72 to 123 GPa).


Bright-Field Analysis Of Phi29 Dna Packaging Motor Using A Magnetomechanical System, Chun-Li Chang, Hui Zhang, Dan Shu, Peixuan Guo, Cagri A. Savran Oct 2008

Bright-Field Analysis Of Phi29 Dna Packaging Motor Using A Magnetomechanical System, Chun-Li Chang, Hui Zhang, Dan Shu, Peixuan Guo, Cagri A. Savran

Birck and NCN Publications

We report a simple and robust magnetomechanical system for direct visual observation of the DNA packaging behavior of the bacteriophage phi29 in real time. The system comprises a micron-sized magnetic bead attached to the free end of the viral DNA, a magnet and a bright-field microscope. We show that the phi29 DNA packaging activity can be observed and dynamically analyzed at the single molecular level in bright field with a relatively simple system. With this system we also visually demonstrate the phi29 motor transporting a cargo 10 000 times the viral size.


Surface Magnetoelectric Effect In Ferromagnetic Metal Films, Chun-Gang Duan, Julian P. Velev, Renat F. Sabirianov, Ziqiang Zhu, Junhao Chu, Sitaram Jaswal, Evgeny Y. Tsymbal Sep 2008

Surface Magnetoelectric Effect In Ferromagnetic Metal Films, Chun-Gang Duan, Julian P. Velev, Renat F. Sabirianov, Ziqiang Zhu, Junhao Chu, Sitaram Jaswal, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

A surface magnetoelectric effect is revealed by density-functional calculations that are applied to ferromagnetic Fe(001), Ni(001), and Co(0001) films in the presence of an external electric field. The effect originates from spin-dependent screening of the electric field which leads to notable changes in the surface magnetization and the surface magnetocrystalline anisotropy. These results are of considerable interest in the area of electrically controlled magnetism and magnetoelectric phenomena.


A Parallel Spectral Element Method For Dynamic Three-Dimensional Nonlinear Elasticity Problems, S. Dong, Z. Yosibash Sep 2008

A Parallel Spectral Element Method For Dynamic Three-Dimensional Nonlinear Elasticity Problems, S. Dong, Z. Yosibash

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We present a high-order method employing Jacobi polynomial-based shape functions, as an alternative to the typical Legendre polynomial-based shape functions in solid mechanics, for solving dynamic three-dimensional geometrically nonlinear elasticity problems. We demonstrate that the method has an exponential convergence rate spatially and a second-order accuracy temporally for the four classes of problems of linear/geometrically nonlinear elastostatics/elastodynamics. The method is parallelized through domain decomposition and message passing interface (MPI), and is scaled to over 2000 processors with high parallel performance.


Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri Sep 2008

Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri

Ganesh Balasubramanian

We simulate unsteady nanoscale thermal transport at a solid-fluidinterface by placing cooler liquid-vapor Ar mixtures adjacent to warmer Fe walls. The equilibration of the system towards a uniform overall temperature is investigated using nonequilibrium molecular dynamics simulations from which the heat flux is also determined explicitly. The Ar–Fe intermolecular interactions induce the migration of fluid atoms into quasicrystallineinterfacial layers adjacent to the walls, creating vacancies at the migration sites. This induces temperature discontinuities between the solidlikeinterfaces and their neighboring fluid molecules. The interfacial temperature difference and thus the heat flux decrease as the system equilibrates over time. The averaged interfacial …


Nanoporous Materials With Enhanced Hydrophilicity And High Water Capacity, Eng-Poh Ng, Svetlana Mintova Sep 2008

Nanoporous Materials With Enhanced Hydrophilicity And High Water Capacity, Eng-Poh Ng, Svetlana Mintova

Eng-Poh Ng

The main types of nanoporous adsorbents for water are identified and described with emphasis on the mechanism of adsorption, modification, improvement of the water sorption capacity, possible regeneration, and stabilization. Among the three main groups of water sorbents, i.e. inorganic materials (zeolites, clays, silica), carbon based materials and organic polymers, the first one is described in details. The significance of their porosity, chemical and structural features relative to the water adsorptive properties of each inorganic type materials is reviewed. Important features for silicates, zeolites, aluminophosphates, mesoporous materials and clays are described, which define the interactions between the water and the …


An Hap/Nanosilver Coating Prepared By Electrochemical Deposition And Its Antibacterial Characterization, Zhi-Wang Geng, Hui Wang, Chang-Jian Lin Aug 2008

An Hap/Nanosilver Coating Prepared By Electrochemical Deposition And Its Antibacterial Characterization, Zhi-Wang Geng, Hui Wang, Chang-Jian Lin

Journal of Electrochemistry

The silver nanoparticles were prepared by sodium citrate reduction of AgNO3.The nanoparticles were electrophoretic deposited on titanium,followed by the electrolytic deposition of hydroxyapatite(HAp).It is revealed,by the high-resolution transmission electron microscopy(HRTEM),that the diameters of nanosilver particles ranged from 5nm to 20nm.The XPS and XRD indicated the coating consisting of silver and HAp.According to the SEM images and antibacterial test,it is demonstrated that when the concentrations of the electrophoretic solution became higher more silver particles were depostited,and the antibacterial property improved.However,the particles aggregated on titanium greatly when the concentration exceeded a point,and the antibacterial activity declined.The optimum concentration for the antibacterial property …


Corrosion Inhibition Of Self-Assembled Films On Iron By Electrochemical Impedance Spectroscopy, Yuan-Yuan Feng, Shen-Hao Chen, Juan-Juan Zhou, Wen-Juan Guo Aug 2008

Corrosion Inhibition Of Self-Assembled Films On Iron By Electrochemical Impedance Spectroscopy, Yuan-Yuan Feng, Shen-Hao Chen, Juan-Juan Zhou, Wen-Juan Guo

Journal of Electrochemistry

The self-assembled films of tetradecylamine were formed on iron surface,and the inhibition ability of which for iron corrosion in 0.5 mol/L H2SO4 solutions was studied by electrochemical impedance spectroscopy technique.Results indicated that longer immersion time would result in stronger inhibition ability of the films.The maximal inhibition efficiency(IE) of the tetradecylamine films was 68.7%.When the tetradecylamine films were modified by dodecylthiol,the mixed films became denser and more stable,thus the inhibition ability increased remarkably.The η of the mixed films increased to 78.2%.


Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding Aug 2008

Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding

Journal of Electrochemistry

The nanoporous gold(NPG) electrodes with uniform pore sizes and ligaments were prepared by using a simple dealloying method.The as-prepared NPG showed high catalytic activity towards the oxidation of formic acid and formaldehyde.After tiny amount of platinum was deposited onto the NPG substrate,not only the structure stability of NPG was greatly improved,but also the Pt-Au bimetallic catalysts displayed the better catalytic activity and the stronger poison resistance towards the electrooxidation of small organic molecules than the bulk platinum due to synergistic effect between Au and Pt compositions.


Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li Aug 2008

Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li

Journal of Electrochemistry

The multi-wall carbon nanotubes(MWNT) were dispersed successfully into water in the presence of dihexadecyl hydrogen phosphate(DHP) and a stable well-distributed suspension.A was formed sensor based on the multi-carbon nanotubes film coated glassy carbon electrode was developed.The electrochemical response of salbutamol was studied by square wave voltammetry.The oxidation peak potential of salbutamol at the modified electrode was observed at 0.604 V,which shifted about 40 mV negatively.The peak current increased 4.5 folds,in contrast to that at a bare electrode.Under optimal measurement conditions,there was a good linear relationship between the peak current(Ipa) and salbutamol concentration(C) in the range from 8.3 × 1 0-7~ …


Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang Aug 2008

Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang

Journal of Electrochemistry

A gold nano-particles modified glassy carbon electrode(GNP/GCE) was prepared by the"seed-mediated gold nano-particles growth method".Field emission scanning electron microscopy,ultraviolet-visible(UV-vis) spectroscopy analysis and electroalaylsis were employed to study the morphology and electrochemical performances.The resulting electrode showed excellent electro-catalytic activity toward the oxidation of salicylic acid and the response sensitivity was 1.8 fold than that obtained on GCE.Good linear relationship was obtained between response current and salicylic acid concentration in the range of 5.0 × 10-7 ~8.0 × 10-5 mol/L,which could be used in the detection of trace salicylic acid.


Electrochemical Synthesis,Characterization And Fluorescence Property Of Nano Na_2sif_6, Guo-Xu Qin, Xin-Jun Wan, Xi-Mei Yuan, Dao-Bao Chu Aug 2008

Electrochemical Synthesis,Characterization And Fluorescence Property Of Nano Na_2sif_6, Guo-Xu Qin, Xin-Jun Wan, Xi-Mei Yuan, Dao-Bao Chu

Journal of Electrochemistry

The nano TiO2 film was prepared by sol-gel process and characterized with X-ray diffraction(XRD) and scanning electron microscope(SEM).It was found that the average size of pore diameter was about 80 nm for the nano TiO2 film.The Nano Na2SiF6 was synthesized by electrochemical deposition on the nanoporous film electrode and characterized with XRD and transmission electron microscope(TEM).The result showed that the average size of nanoparticle was 20 nm for the nano Na2SiF6.The fluorescence property of nano Na2SiF6 was also studied briefly.The result indicated that the nano Na2SiF6 exhibited strong fluorescence emission at 452.4 nm and 285 nm,respectively.


Level Spectrum Of Single Gated As Donors, Gabriel P. Lansbergen, Rajib Rahman, J. Caro, N. Collaert, S. Biesemans, Gerhard Klimeck, S. Rogge, L.C. L. Hollenberg Jul 2008

Level Spectrum Of Single Gated As Donors, Gabriel P. Lansbergen, Rajib Rahman, J. Caro, N. Collaert, S. Biesemans, Gerhard Klimeck, S. Rogge, L.C. L. Hollenberg

Other Nanotechnology Publications

We study the electrical transport through single As donors incorporated in the channel of a FinFET, i.e. a donor in a three-terminal geometry. By means of spectroscopic measurements in conjuction with a NEMO-3D model, we can identify the excited states and associate them with either the donors Coulomb potential, a triangular well at the interface or a hybridized combination of the two. The correspondence between the transport measurements, the theoretical model and the local environment provides an atomic understanding of actual gated donors in a nanostructure.