Browsing by Author "Huang, Ting-Kai"

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(110)-Exposed Gold Nanocoral Electrode as Low Onset Potential Selective Glucose Sensor
(2010-10-01)
Cheng, Ta-Ming
;
Huang, Ting-Kai
;
Lin, Huang-Kai
;
Tung, Sze-Ping
;
Chen, Yu-Liang
A straightforward electrochemical deposition process was developed to grow gold nanostructures, including nanocoral, nanothorn, branched belt, and nanoparticle, on carbon electrodes by reducing HAuCl(4) under constant potentials in mixtures containing CTAC and/or NaNO(3). Among the nanostructures, the quasi-one-dimensional nanocoral electrode showed the highest surface area. Because of this, it provided excellent electrochemical performances in cyclic voltammetric (CV) studies for kinetic-controlled enzyme-free glucose oxidation reactions. In amperometric studies carried out at 0.200 V in PBS (pH 7.40, 0.100 M), the nanocoral electrode showed the highest anodic current response. It also offered the greatest sensitivity, 22.6 mu AmM(-1)cm(-2), an extended linear range, 5.00 x 10(-2) mM to 3.00 x 10(1) mM, and a low detection limit, 1.00 x 10(1) mu m among the electrodes investigated in this study. In addition, the glucose oxidation by the nanocoral electrode started at -0.280 V. more negative than the one of using a commercial Au electrode as the working electrode. This is attributed to the presence of exposed Au (110) surfaces on the electrode. The feature was applied to oxidize glucose selectively in the presence of ascorbic acid (AA) and uric acid (UA), common interferences found in physiological analytes. With an applied voltage at -0.100 V. the AA oxidation (started at -0.080 V) can be avoided while the glucose oxidation still provides a significant response.
(110)-Exposed Gold Nanocoral Electrode as Low Onset Potential Selective Glucose Sensor
(2010-10-01)
Cheng, Ta-Ming
;
Huang, Ting-Kai
;
Lin, Huang-Kai
;
Tung, Sze-Ping
;
Chen, Yu-Liang
A straightforward electrochemical deposition process was developed to grow gold nanostructures, including nanocoral, nanothorn, branched belt, and nanoparticle, on carbon electrodes by reducing HAuCl(4) under constant potentials in mixtures containing CTAC and/or NaNO(3). Among the nanostructures, the quasi-one-dimensional nanocoral electrode showed the highest surface area. Because of this, it provided excellent electrochemical performances in cyclic voltammetric (CV) studies for kinetic-controlled enzyme-free glucose oxidation reactions. In amperometric studies carried out at 0.200 V in PBS (pH 7.40, 0.100 M), the nanocoral electrode showed the highest anodic current response. It also offered the greatest sensitivity, 22.6 mu AmM(-1)cm(-2), an extended linear range, 5.00 x 10(-2) mM to 3.00 x 10(1) mM, and a low detection limit, 1.00 x 10(1) mu m among the electrodes investigated in this study. In addition, the glucose oxidation by the nanocoral electrode started at -0.280 V. more negative than the one of using a commercial Au electrode as the working electrode. This is attributed to the presence of exposed Au (110) surfaces on the electrode. The feature was applied to oxidize glucose selectively in the presence of ascorbic acid (AA) and uric acid (UA), common interferences found in physiological analytes. With an applied voltage at -0.100 V. the AA oxidation (started at -0.080 V) can be avoided while the glucose oxidation still provides a significant response.
Electrochemical Growth of Gold Nanostructures for Surface-Enhanced Raman Scattering
(2011-02-10)
Yang, Yu-Cheng
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Huang, Ting-Kai
;
Chen, Yu-Liang
;
Mevellec, Jean-Yves
;
Lefrant, Serge
We demonstrate a facile fabrication of gold nanostructures including Au nanoplates (NPs), Au nanothorns (NTs), and Au nanowires (NWs) on indium tin oxide substrates via electrochemical growth. A simple two-electrode electrochemical deposition system was applied for the fabrication process. Dense Au nanostructures were grown directly on an Au seeding layer on the substrate. After 48 h, the Au NPs were 2-5 mu m in width and 150-200 nm in thickness. The Au NTs were 1-3 mu m in height, 300-500 nm in bottom side width, and 20 nm at the apex. The Au NWs were 30-80 nm in diameter and about 20 mu m in length. The entire process was template-free and economical. We investigated the correlation between surface plasmon resonance (SPR) and surface enhanced scattering (SERS) effects of the Au nanostructures with different excitation wavelengths. By using the SPR absorption maxima of the nanostructures as the excitation wavelengths for SERS, the highest SERS enhancements were achieved. SERS effects of the Au NWs were investigated further. We discovered that the length and the density of the Au NWs affected the SERS performance significantly. The result is rationalized by the amount of "hot spot" generated at the crossing of the Au NWs. With the Au NWs, Rhodamine 6G can be detected at a concentration as low as 10(-9) M.
Electrochemical growth of gold nanostructures on carbon paper for alkaline direct glucose fuel cell
(2012)
Tung, Sze-Ping
;
Huang, Ting-Kai
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
應用化學系
Au nanocorals and nanoparticles were grown on carbon papers via a simple two-electrode electrochemical deposition process by reducing HAuCl(4) under constant potentials in mixtures containing cetyltrimethylammonium chloride (CTAC) and/or NaNO(3). Electrochemical characterizations showed that the nanocoral electrode exhibited high surface area and high electrocatalytic activity towards glucose oxidation in alkaline media. These Au nanostructures were employed as anodes and assembled with anion exchange membranes and Pt cathodes for alkaline direct glucose fuel cell (DGFC) investigations. Open-circuit voltages (OCVs) of the Au nanocoral and nanoparticle electrodes were 0.64 V and 0.61 V, and their maximum power densities were 0.847mWcm(-2) and 0.336mWcm(-2), respectively. The cells showed stable output over 5 h with a small decrease in OCV (6.9%). The electrodes could be refreshed after electrochemical reduction steps.
Field Emission and Superhydrophobic Properties of Electrochemically Grown Gold Nanourchins
(2012-08-01)
Huang, Ting-Kai
;
Huang, Hsin-Wei
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
應用化學系
"We demonstrate a convenient fabrication of Au nanourchins (NUs) on Si substrates via a surfactant-assisted galvanic reduction process. This synthetic method not only grows Au NUs on Si in a one-step process but also effectively controls the lengths of the branches on the NUs. The widths are about 100-120 nm and the lengths can be extended from 200 nm to 5 mu m by lengthening the growth time. With the advantage of a hierarchical surface structure, Au NUs exhibited excellent electron field emission (FE) performance (turn-on voltage, 6.3 V/mu m; beta, 1150). In addition, the wetting behavior examination shows that the water contact angle can be as high as 158 degrees on Au NUs after the material is treated by 1-hexadecanethiol."
Glucose sensing by electrochemically grown copper nanobelt electrode
(2009-11-15)
Huang, Ting-Kai
;
Lin, Kuan-Wen
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Tung, Sze-Ping
;
Cheng, Ta-Ming
;
Chang, I-Chun
A simple design of growing Cu nanobelt (NB) electrode for glucose sensing is presented. Cu NBs were grown directly on carbon electrodes by using electrochemical deposition. The average width, thickness and length of the NBs were about 50 nm, 20 nm and several tens of micrometers, respectively. Cyclic voltammetric (CV) experiments showed that a Cu NB electrode grown by a reduction charge of 0.5 C on a substrate of 0,018 cm(2) enhanced glucose oxidation ability. For glucose sensing, the electrode exhibited a high sensitivity of 79.8 mu A/mM and a measurable detection limit of 10 mu M in amperometric detection. (C) 2009 Elsevier B.V. All rights reserved.
Growth of Cu nanobelt and Ag belt-like materials by surfactant-assisted galvanic reductions
(2007-05-08)
Huang, Ting-Kai
;
Cheng, Tzu-Hou
;
Yen, Ming-Yu
;
Hsiao, Wei-Han
;
Wang, Lung-Shen
We demonstrate the syntheses of single crystalline Cu nanobelt and Ag belt-like materials via CTAC-assisted (CTAC, cetyltrimethylammonium chloride) galvanic reductions. The single crystalline face-centered cubic phase Cu nanobelt was prepared by reacting CuCl2(aq) with Al(s) in an aqueous solution of CTAC and HNO3. The Cu nanobelt exhibited a high-quality ribbon-like nanostructure with a thickness less than 15 nm, a width of 30-150 nm, and a length up to 10 mu m. The belt-like Ag, with a thickness less than 10 nm, a width of 30-100 nm, a length up to 5 mu m, and a novel single crystalline 4H structure, was prepared by reacting AgNO3(aq) and Cu(s) in an aqueous solution of CTAC.
Growth of high-aspect-ratio gold nanowires on silicon by surfactant-assisted galvanic reductions
(2008-06-03)
Huang, Ting-Kai
;
Chen, Ying-Chieh
;
Ko, Hsin-Chun
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Huang, Hsin-Wei
;
Wang, Chia-Hsin
A simple galvanic reduction for direct growth of An nanowires on silicon wafers is developed. The nanowires were prepared by reacting HAuCl4(aq) with Sn-(s) in the presence of CTAC((aq)) (cetyltrimethylammonium chloride) and NaNO3(aq), which were important to the product morphology development. The nanowire diameter was 50-100 nm, and the length was more than 20 mu m.
Growth of Pagoda-Topped Tetragonal Copper Nanopillar Arrays
(2009-07-01)
Chang, I-Chun
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Huang, Ting-Kai
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Lin, Huang-Kai
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Tzeng, Yu-Feng
;
Peng, Chih-Wei
Growth of arrays of pagoda-topped tetragonal Cu nanopillar (length 1 - 6 mu m; width 150 +/- 25 nm) with {100) side races on Au/glass is achieved by,a simple electrochemical reduction of CuCl(2)(aq) by Al(s) in aqueous dodecyltrimethylammonium chloride. Field-emission measurement shows that the Cu nanopillars can emit electrons (10 mu A cm(-2)) at a turn-on field or 12.4 V mu m(-1) with a calculated held enhancement factor of 713.
Ni/NiO/HfO2 Core/Multishell Nanowire ReRAM Devices with Excellent Resistive Switching Properties
(2018-11-01)
Huang, Ting-Kai
;
Chen, Jui-Yuan
;
Ting, Yi-Hsin
;
Wu, Wen-Wei
;
交大名義發表
Resistive random-access memory (ReRAM) is one of the most promising types of nonvolatile memory because it has several important advantages, for example, a simple metal-insulator-metal structure, fast operating speed, high endurance, high retention, and low energy consumption. However, the reliability of ReRAM nanodevices is not persistent, and the complete switching mechanism is not fully understood. In this study, a unique 1D Ni/NiO/HfO2 core/multishell ReRAM nanodevice is designed and fabricated. The different properties, including the electrical characteristics, surface morphology, and elemental distribution, are systematically investigated. The Ni/NiO/HfO2 heterostructure nanowire ReRAM device exhibits excellent electrical characteristics and resistive switching properties. It is remarkable that the endurance could be maintained up to 200 cycles, which is extremely good for a 1D ReRAM device. Additionally, a focused-ion beam technique is used to prepare samples for subsequent transmission electron microscopic (TEM) observation. From the TEM analysis, the position of the conducting filaments is verified and the elemental composition of the conducting filaments is confirmed. The migration of hafnium ions forms the conducting filaments between the HfO2 layer and Ni core, resulting in the switching characteristic. The study enriches the understanding of the mechanism and provides a design to enhance the resistive switching properties of ReRAM nanodevices.
Observation of Resistive Switching Behavior in Crossbar Core-Shell Ni/NiO Nanowires Memristor
(2018-02-08)
Ting, Yi-Hsin
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Chen, Jui-Yuan
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Huang, Chun-Wei
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Huang, Ting-Kai
;
Hsieh, Cheng-Yu
The crossbar structure of resistive random access memory (RRAM) is the most promising technology for the development of ultrahigh-density devices for future nonvolatile memory. However, only a few studies have focused on the switching phenomenon of crossbar RRAM in detail. The main purpose of this study is to understand the formation and disruption of the conductive filament occurring at the crossbar center by real-time transmission electron microscope observation. Core-shell Ni/NiO nanowires are utilized to form a cross-structure, which restrict the position of the conductive filament to the crosscenter. A significant morphological change can be observed near the crossbar center, which results from the out-diffusion and backfill of oxygen ions. Energy dispersive spectroscopy and electron energy loss spectroscopy demonstrate that the movement of the oxygen ions leads to the evolution of the conductive filament, followed by redox reactions. Moreover, the distinct reliability of the crossbar device is measured via ex situ experiments. In this work, the switching mechanism of the crossbar core-shell nanowire structure is beneficial to overcome the problem of nanoscale minimization. The experimental method shows high potential to fabricate high-density RRAM devices, which can be applied to 3D stacked package technology and neuromorphic computing systems.
Rectangular copper nanotubes
(2015-01-01)
Chang, Yu-Hsu
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Hsu, Ya-Ting
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Tsai, Yu-Heng
;
Lai, Yi-Ru
;
Huang, Ting-Kai
One-dimensional Cu nanomaterials with a new morphology, rectangular copper nanotubes (copper NTs), were synthesized on a large-scale using a cetyltrimethylammonium chloride-assisted galvanic replacement reaction on rough Al substrates. In an acidic environment, Cu(II) is reduced on sharp-topped Al substrates and copper NTs 150-300 nm in diameter and 2-10 mm in length were formed through fine-tuning the reaction temperature and chemical stoichiometry. Field-emission measurement results show that the copper NTs emitting electrons at turn-on fields of 8.76 V mu m(-1) was observed with a field enhancement factor of 85. The superior catalytic property of copper NTs in the degradation of a methylene blue aqueous solution in the presence of H2O2 was also presented in this article.
Urchin-like Ag Nanowires as Non-enzymatic Hydrogen Peroxide Sensor
(2012-04-01)
Hsiao, Wei-Han
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Chen, Hsin-Yu
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Cheng, Ta-Ming
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Huang, Ting-Kai
;
Chen, Yu-Liang
Urchin-like Ag nanowires were prepared by reacting AgNO3(aq) with Cu metal in the presence of cetyltrimethylammonium chloride and HNO3(aq) on a screen printed carbon electrode at room temperature. The diameters of the nanowires were about 100 nm, while the lengths were up to 10 mu m. Cyclic voltammetric experiments using the Ag nanowires as the working electrode showed electrocatalytic H2O2 reduction. The electrode exhibited a high sensitivity of 4705 mu A mM(-3) me cm(-2) from 50 mu M to 10.35 rnM and a measurable detection limit of 10 mu M in amperometric detection. This is the first report on Ag NWs for non-enzymatic H2O2 sensing.