Zhun yi wei na mi jie gou zai guang fu, guang cui hua ji deng li zi ti ji yuan fang mian de ying yong

在本篇論文中，我們成功地在透明導電襯底上製備了一系列準一維納米材料陣列。我們首先製備了氧化鋅納米線陣列，然後把它們用作氧化鋅/硒化鎘核殼納米線纜陣列中的核以及合成硒化鎘和碲化鎘納米管陣列所需的犧牲模板。最後，金納米管陣列則是利用之前製備的硒化鎘納米管陣列為模板合成的。氧化鋅納米線陣列是通過高溫的熱蒸法和低溫的水熱法製備的。水熱法製備的氧化鋅納米線陣列的電導高於熱蒸法製備的氧化鋅納米線陣列，這使得水熱法製備的氧化鋅納米線更適合採用與電相關的後續處理方法。當氧化鋅納米線陣列被用作犧牲模板來製備納米管時，水熱法製備的氧化鋅納米線能被輕易地完全去除。基於這些認識，我們主要採用電化學沉積法在水熱法製備的氧化鋅納米線陣列表面沉積硒化鎘，得到了氧化鋅/硒化鎘核殼納米線纜陣列。接下來，我們將納米線纜陣列光電極和沉積了鉑催化劑的對電極組裝成三文治結構的太陽能電池。研究發現，採用多硫電解液的電池性能比碘基電解液的電池好，其中成分為1摩爾每升硫化鈉，1摩爾每升硫和1摩爾每升氫氧化鈉的多硫電解液的電池效率最高。當去除電化學沉積法生長的氧化鋅/硒化鎘和氧化鋅/碲化鎘核殼納米線纜陣列中的氧化鋅核以後，便在導電襯底上得到了硒化鎘和碲化鎘的納米管陣列。儘管兩種納米管陣列都對可見光有很強的吸收，但是，硒化鎘納米管陣列相比碲化鎘納米管陣列，表現出較高的光響應和較好的光催化降解亞甲基藍的活性。這是因為該樣品中的光生載流子能有效分離，同時能參與化學反應的表面積也較大。最後，我們選用硒化鎘納米管陣列作為模板，利用化學方法製備了金納米管陣列。金納米管的尺寸可以通過控制硒化鎘納米管模板來加以調節。當我們將具有拉曼活性的4-巰基苯甲酸分子吸附到金納米管的表面時，其拉曼散射相比未吸附時，顯著地增強了約四個數量級，如此大的提高來源於金納米管表面附近的局域電場增強效應。In this thesis, we demonstrated the synthesis of a series of pseudo-one-dimensional nanostructure arrays on transparent conducting substrates. We started with ZnO nanowire arrays, which were then served as the core for the ZnO/CdSe core/shell nanocable arrays formation. Further taking the ZnO as sacrificial templates led to the formation of CdSe (and CdTe) nanotube arrays. Finally, Au nanotube arrays were fabricated using the CdSe nanotube arrays as the template. ZnO nanowire arrays were synthesized via high-temperature thermal evaporation method (TE) and low temperature hydrothermal method (HT). The electrical conductivity of HT samples on the substrates was higher than that of the TE counterparts, making it attractive for further electrical-based processing. When serving as the sacrificial templates for nanotube fabrication, HT nanowires can be completely removed with ease. Based on these understanding, ZnO/CdSe core/shell nanocable arrays were obtained mainly via electrochemical deposition of CdSe on HT ZnO nanowire arrays. Nanocable-array-photoelectrode was assembled with a Pt-coated counter electrode into a sandwiched solar cell. Polysulfide electrolytes with various compositions were found to work better than iodine-based ones for such cells, and the cell with the polysulfide electrolyte containing 1 M Na₂S, 1 M S and 1 M NaOH showed highest efficiency. Removal of the ZnO cores in the electrodeposited ZnO/CdSe and ZnO/CdTe nanocable arrays left CdSe and CdTe nanotube arrays on the conducting substrate. Although strong visible-light absorption was observed from both two nanotube arrays, higher photocurrent and better photocatalytic degradation activity of methlyene blue were recorded from CdSe-nanotube-array samples (as compared to the CdTe ones), owing to effective charge separation and large surface area for chemical reactions. Lastly, Au nanotube arrays were synthesized via chemical method using CdSe nanotube arrays as the template. The dimensions of the Au nanotubes, as replicated from CdSe nanotubes, were tunable. When absorbed on the Au nanotube arrays surface, the Raman scattering of 4-mercaptobenzoic acid (a Raman-active molecule) was greatly enhanced for~4 orders of magnitude compared to the signals from the dry powder of the same molecule. Such large increase was due to the strong local electrical field enhancement near the Au nanotubes surface.Detailed summary in vernacular field only.Zhu, Haojun = 準一維納米結構在光伏、光催化及等離子體激元方面的應用 / 朱浩君.Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.Includes bibliographical references (leaves 141-168).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstract also in Chinese.Abstracts in English and Chinese.Zhu, Haojun = Zhun yi wei na mi jie gou zai guang fu, guang cui hua ji deng li zi ti ji yuan fang mian de ying yong / Zhu Haojun.Abstract --- p.i摘要 --- p.iiiAcknowledgements --- p.ivContents --- p.vList of Figures --- p.viiiList of Tables --- p.xviiiChapter Chapter 1 --- Introductions --- p.1Chapter Chapter 2 --- Background --- p.4Chapter 2.1. --- Nanostructured Photovoltaic (PV) Solar Cells --- p.4Chapter 2.1.1. --- Fundamental physics of nanostructures for solar cell applications --- p.5Chapter 2.1.2. --- Inorganic nano-architectures for PV cells --- p.9Chapter 2.2. --- Nanostructures for Photocatalytic Degradation of Organic Pollutants --- p.18Chapter 2.2.1 --- Overview of photocatalytic degradation of organic pollutants --- p.19Chapter 2.2.2 --- Photocatalysis under visible light illumination --- p.24Chapter 2.3. --- Plamonic Noble Metal Nanostructures --- p.29Chapter 2.3.1 --- Surface plasmons of noble metal nanostructures --- p.29Chapter 2.3.2 --- Applications of plasmonic noble metal nanostructures in solar energy conversion and sensing --- p.35Chapter Chapter 3 --- Methodologies and Instrumentations --- p.45Chapter 3.1. --- Materials Growth Methodologies --- p.45Chapter 3.1.1. --- Thermal evaporation (TE) methods --- p.45Chapter 3.1.2. --- Hydrothermal (HT) methods --- p.47Chapter 3.1.3. --- Electrodeposition (ED) methods --- p.49Chapter 3.1.4. --- Prototype solar cells assemble --- p.52Chapter 3.2. --- Characterization Techniques --- p.53Chapter 3.2.1. --- Morphological, structural, and compositional analysis using electron microscopy based techniques --- p.53Chapter 3.2.2. --- Photoelectrochemical (PEC) performance test --- p.63Chapter 3.2.3. --- Photocatalytic degradation of organic pollutants --- p.65Chapter 3.2.4. --- Single-particle scattering imaging and spectroscopy --- p.67Chapter Chapter 4 --- ZnO Nanowire Arrays on Conducting Substrates -- A Comparison on the Growth Methodology --- p.71Chapter 4.1. --- Introduction --- p.71Chapter 4.2. --- Experimental --- p.72Chapter 4.3. --- Results and Discussions --- p.75Chapter 4.3.1 --- Morphologies, crystal structures and chemical compositions --- p.75Chapter 4.3.2 --- ZnO nanowire arrays used as electrodes --- p.80Chapter 4.3.3 --- ZnO nanowire arrays used as sacrificial templates in electroplating . --- p.85Chapter 4.4. --- Conclusions --- p.88Chapter Chapter 5 --- ZnO-core/CdSe-shell Nanocable Arrays for Photovoltaic Solar Cells --- p.89Chapter 5.1. --- Introduction --- p.89Chapter 5.2. --- Experimental --- p.90Chapter 5.3. --- Results and Discussions --- p.93Chapter 5.3.1 --- Synthesis of the ZnO-core/CdSe-shell nanocable arrays on ITO/glass --- p.93Chapter 5.3.2 --- The photovoltaic (PV) performance --- p.100Chapter 5.4. --- Conclusions --- p.107Chapter Chapter 6 --- CdSe and CdTe Nanotube Arrays as Visible-light-driven Photocatalyst for Organic Pollutant Degradation --- p.108Chapter 6.1. --- Introduction --- p.108Chapter 6.2. --- Experimental --- p.109Chapter 6.3. --- Results and Discussions --- p.112Chapter 6.3.1. --- Morphology, crystal structure, and chemical composition of the nanotube arrays --- p.112Chapter 6.3.2. --- Optical properties --- p.116Chapter 6.3.3. --- Photoelectrochemical (PEC) performance --- p.117Chapter 6.3.4. --- Photocatalytic activities --- p.120Chapter 6.4. --- Conclusions --- p.123Chapter Chapter 7 --- Fabrication of Au Nanotube Arrays and Their Plasmonic Properties --- p.124Chapter 7.1. --- Introduction --- p.124Chapter 7.2. --- Experimental --- p.125Chapter 7.3. --- Results and Discussions --- p.127Chapter 7.3.1. --- Morphology, crystalline structure, and chemical composition of Au nanotube arrays --- p.127Chapter 7.3.2. --- Au nanotube formation mechanism --- p.129Chapter 7.3.3. --- Plasmonic properties of Au nanotube arrays on ITO/glass substrates --- p.131Chapter 7.3.4. --- Plasmonic properties of single Au nanotubes --- p.133Chapter 7.3.5. --- Au nanotube arrays on ITO/glass as SERS substrates --- p.134Chapter 7.4. --- Conclusions --- p.138Chapter Chapter 8 --- Conclusions --- p.139Bibliography --- p.14