東華大學圖書館 |

Gold Nanobipyramid-Based Bimetallic Nanostructures.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Gold Nanobipyramid-Based Bimetallic Nanostructures./
作者:	Yip, Hang Kuen.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
面頁冊數:	207 p.
附註:	Source: Dissertations Abstracts International, Volume: 80-06, Section: B.
Contained By:	Dissertations Abstracts International80-06B.
標題:	Nanoscience. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=11012266
ISBN:	9780438659681

Gold Nanobipyramid-Based Bimetallic Nanostructures.
Yip, Hang Kuen.

Gold Nanobipyramid-Based Bimetallic Nanostructures. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 207 p.

Source: Dissertations Abstracts International, Volume: 80-06, Section: B.

Thesis (Ph.D.)--The Chinese University of Hong Kong (Hong Kong), 2018.

This item must not be sold to any third party vendors.

Noble metal nanostructures have drawn great interest from scientists and led to a rapid development in a scientific research field known as plasmonics in the past several decades. Localized surface plasmon resonances (LSPRs), which refer to the collective oscillations of free charge carriers confined within nanostructures under resonance excitation, endow the nanostructures with extraordinary optical, photothermal and catalytic properties. Among the various members in the family of plasmonic nanostructures, Au nanobipyramids (NBPs) exhibit superior plasmonic properties such as remarkable electric-field enhancement and narrow plasmon peak widths, making them highly promising in plasmon-based applications. On the other hand, bimetallic nanostructures integrating two types of metals exhibit unique plasmonic properties that cannot be easily replicated by monometallic nanostructures. The investigation of Au NBP-based bimetallic nanostructures is important in the field of plasmonics as they combine the advantages of Au NBPs and bimetallic nanostructures. In this thesis, I report on my efforts on the investigation of Au NBP-based bimetallic nanostructures and their related applications, including Au NBP Pd core shell bimetallic nanostructures for hydrogen sensing, AgPd-tipped Au NBPs for precise control of the plasmon resonance wavelength over the entire near-infrared (NIR) range, and Au NBP-directed high-aspect-ratio Ag nanorods (NRs) for broadside nanoantennas. First, I will present my studies on the plasmonic hydrogen sensors constructed by Au NBP Pd core shell bimetallic nanostructures, which show outstanding performances in terms of sensitivity and repeatability. The hydrogen concentration can be detected by measuring the LSPR peak shifts of the Au NBP Pd core shell bimetallic nanostructures deposited on glass substrates. I have synthesized Au NBP Pd core shell bimetallic nanostructures with tunable Pd shell thicknesses and morphologies for the optimization of the sensing performances of the constructed hydrogen sensors. A maximal LSPR peak shift of 97 nm is achieved at 4 vol% hydrogen concentration by optimizing the Pd shell thickness of the nanostructures. Furthermore, the maximal LSPR peak shift can be further improved to 140 and 147 nm at 2 and 4 vol% hydrogen concentrations, respectively, by optimizing the Pd shell morphology of the nanostructures. I have also investigated the hydrogen sensing performances of Au NBP/AgPd trimetallic nanostructures. From my studies, I have demonstrated two attractive ways for improving the sensitivities of the hydrogen sensors, that is, choosing plasmonic cores with outstanding refractive index sensitivities and depositing continuous Pd shell in the regions with the greatest electric field enhancement. Next, I will describe my studies on the AgPd-tipped Au NBPs, which exhibit highly controllable LSPR wavelengths in a wide spectral range. Ag and Pd atoms have been successfully overgrown on the tips of Au NBPs with the assistance of a pre-grown Ag layer. I have demonstrated the optimization of the overgrowth conditions for the synthesis of the AgPd-tipped Au NBPs with the largest LSPR redshifts reaching ~900 nm. Remarkable redshifts of the LSPR peaks over the entire NIR region have been realized by the unique morphologies of these nanostructures. I have further generalized the metal-tipping deposition approach in three ways, including the employment of Au NBPs exhibiting different longitudinal dipolar LSPR wavelengths, the replacement of Au NBPs with Au NRs as the cores, and the use of different types of tipping metals. Finite-difference time-domain (FDTD) simulations have been employed to verify the experimental significant redshifts of the LSPR peaks. In addition, I have experimentally demonstrated the outstanding photothermal conversion efficiency of the AgPd-tipped Au NBPs, indicating that such nanostructures are highly suitable for photothermal cancer therapy in the second biological transparency window. Finally, I will present my studies on applying Au NBP-directed high-aspect-ratio Ag NRs as optical nanoantennas for directional light scattering. The lengths and diameters of the synthesized Ag NRs can be precisely tailored by the selection of the amount of the Ag precursor and the size of the core Au NBPs, respectively. I have investigated the directional far-field scattering behaviors of the Ag NRs supported on Si substrates by analyzing their single-particle dark-field scattering images. Each of the individual Si-supported high-aspect-ratio Ag NRs can scatter the incident light into their two flanks under particular excitation conditions. The conditions for the observation of the directional dark-field scattering have been systemically studied, including the effect of the gap distance between the Si-supported Ag NRs and Si substrates, the dimensional effect of the Si-supported Ag NRs, and the effect of the incidence angle and polarization of the excitation light. These directional scattering behaviors have been verified by FDTD simulations. I have further developed a theoretical model of side-by-side electric dipole arrays for understanding the directional scattering behaviors. (Abstract shortened by ProQuest.).

ISBN: 9780438659681Subjects--Topical Terms:

587832
Nanoscience.

Gold Nanobipyramid-Based Bimetallic Nanostructures.
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506 $a This item must not be sold to any third party vendors.
506 $a This item must not be added to any third party search indexes.
520 $a Noble metal nanostructures have drawn great interest from scientists and led to a rapid development in a scientific research field known as plasmonics in the past several decades. Localized surface plasmon resonances (LSPRs), which refer to the collective oscillations of free charge carriers confined within nanostructures under resonance excitation, endow the nanostructures with extraordinary optical, photothermal and catalytic properties. Among the various members in the family of plasmonic nanostructures, Au nanobipyramids (NBPs) exhibit superior plasmonic properties such as remarkable electric-field enhancement and narrow plasmon peak widths, making them highly promising in plasmon-based applications. On the other hand, bimetallic nanostructures integrating two types of metals exhibit unique plasmonic properties that cannot be easily replicated by monometallic nanostructures. The investigation of Au NBP-based bimetallic nanostructures is important in the field of plasmonics as they combine the advantages of Au NBPs and bimetallic nanostructures. In this thesis, I report on my efforts on the investigation of Au NBP-based bimetallic nanostructures and their related applications, including Au NBP Pd core shell bimetallic nanostructures for hydrogen sensing, AgPd-tipped Au NBPs for precise control of the plasmon resonance wavelength over the entire near-infrared (NIR) range, and Au NBP-directed high-aspect-ratio Ag nanorods (NRs) for broadside nanoantennas. First, I will present my studies on the plasmonic hydrogen sensors constructed by Au NBP Pd core shell bimetallic nanostructures, which show outstanding performances in terms of sensitivity and repeatability. The hydrogen concentration can be detected by measuring the LSPR peak shifts of the Au NBP Pd core shell bimetallic nanostructures deposited on glass substrates. I have synthesized Au NBP Pd core shell bimetallic nanostructures with tunable Pd shell thicknesses and morphologies for the optimization of the sensing performances of the constructed hydrogen sensors. A maximal LSPR peak shift of 97 nm is achieved at 4 vol% hydrogen concentration by optimizing the Pd shell thickness of the nanostructures. Furthermore, the maximal LSPR peak shift can be further improved to 140 and 147 nm at 2 and 4 vol% hydrogen concentrations, respectively, by optimizing the Pd shell morphology of the nanostructures. I have also investigated the hydrogen sensing performances of Au NBP/AgPd trimetallic nanostructures. From my studies, I have demonstrated two attractive ways for improving the sensitivities of the hydrogen sensors, that is, choosing plasmonic cores with outstanding refractive index sensitivities and depositing continuous Pd shell in the regions with the greatest electric field enhancement. Next, I will describe my studies on the AgPd-tipped Au NBPs, which exhibit highly controllable LSPR wavelengths in a wide spectral range. Ag and Pd atoms have been successfully overgrown on the tips of Au NBPs with the assistance of a pre-grown Ag layer. I have demonstrated the optimization of the overgrowth conditions for the synthesis of the AgPd-tipped Au NBPs with the largest LSPR redshifts reaching ~900 nm. Remarkable redshifts of the LSPR peaks over the entire NIR region have been realized by the unique morphologies of these nanostructures. I have further generalized the metal-tipping deposition approach in three ways, including the employment of Au NBPs exhibiting different longitudinal dipolar LSPR wavelengths, the replacement of Au NBPs with Au NRs as the cores, and the use of different types of tipping metals. Finite-difference time-domain (FDTD) simulations have been employed to verify the experimental significant redshifts of the LSPR peaks. In addition, I have experimentally demonstrated the outstanding photothermal conversion efficiency of the AgPd-tipped Au NBPs, indicating that such nanostructures are highly suitable for photothermal cancer therapy in the second biological transparency window. Finally, I will present my studies on applying Au NBP-directed high-aspect-ratio Ag NRs as optical nanoantennas for directional light scattering. The lengths and diameters of the synthesized Ag NRs can be precisely tailored by the selection of the amount of the Ag precursor and the size of the core Au NBPs, respectively. I have investigated the directional far-field scattering behaviors of the Ag NRs supported on Si substrates by analyzing their single-particle dark-field scattering images. Each of the individual Si-supported high-aspect-ratio Ag NRs can scatter the incident light into their two flanks under particular excitation conditions. The conditions for the observation of the directional dark-field scattering have been systemically studied, including the effect of the gap distance between the Si-supported Ag NRs and Si substrates, the dimensional effect of the Si-supported Ag NRs, and the effect of the incidence angle and polarization of the excitation light. These directional scattering behaviors have been verified by FDTD simulations. I have further developed a theoretical model of side-by-side electric dipole arrays for understanding the directional scattering behaviors. (Abstract shortened by ProQuest.).
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