http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/83233 2026-04-05T18:46:35Z 2026-04-05T18:46:35Z 汪奕達 I-Ta Wang http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/96827 2025-03-19T09:54:30Z 2024-01-01T00:00:00Z

標題: 碲化銅中增強的波動狀電荷密度波序化促進電子的加速與輕化; The Growing Charge-Density-Wave Order in CuTe Lightens and Speeds up Electrons 作者: 汪奕達; I-Ta Wang 摘要: 隨著量子材料的出現，越來越多有趣的性質開始被大家研究並檢視。近年來，擁有在對稱保護下表現線性色散能帶的拓樸半金屬引起了大家的注意，這樣特殊的能帶結構，會造成特別的電荷屏蔽效應。我們利用電荷響應函數(Charge Response Function)去計算電磁易感率(Susceptibility)特別是電荷密度波(CDW)存在於材料中的情況，可幫助我們了解拓樸量子材料中有趣的電子結構。在本論文中，我們利用動量解析電子能量損失光譜(q-EELS)以及古典電漿子(plasmon)色散關係去偵測並且計算材料中載子的有效質量和費米速度，我們發現在碲化銅(CuTe)中，載子的有效質量和費米速度隨著電荷密度波序化的增強而分別變輕和增快，這與一般擁有電荷密度波的材料所表現的行為相反，也是本論文想要探討的主要目標。 在第一章中，我們對於量子材料和電荷屏蔽效應進行簡單的介紹，我們藉由對稱性的觀點切入量子材料，分別由反對稱中心和時間反演對稱中心以及破壞對於狄拉克(Dirac)和外爾(Weyl)費米子進行探討；我們也在電荷屏蔽的章節裡，簡單介紹電荷密度波、電漿子以及德汝德-勞倫茲模型(Drude-Lorentz Model)。在第二章，我們詳細的闡述掃瞄式穿透電子顯微鏡以及動量解析電子能量損失光譜的原理和應用。在第三章中，我們討論了關於碲化銅在動量解析電子能量損失光譜的結果，在不同動量空間下的光譜中，我們可以利用電漿子的色散關係得到相關載子的有效質量和費米速度，在碲化銅中，主要載子來源於線性色散能帶的輕電子以及與其垂直方向的重電洞。 在第四章中，我們探討在不同溫度下的動量解析電子能量損失光譜的實驗結果，因為隨著溫度低於電荷密度波相轉變溫度，電荷密度波序化會隨著溫度降低而增強，我們可以觀察電荷密度波序化增強與載子的關係。在室溫時，線性色散能帶的電子，同時也是與電荷密度波序化相關的載子，其有效質量約為0.28倍的電子靜止質量(m0)，而其費米速度則約為光速的0.005倍。隨著溫度的降低和電荷密度波序化的增強，我們發現輕電子的有效質量變得更輕並且費米速度變得更快。在溫度到100 K時，載子的有效質量和費米速度相對於室溫時，變輕和增快約百分之20。我們推測，造成這樣的原因，是因為線性色散的能帶在低溫下進行能帶的重整化(Band Renormalization)，使得能帶變的更陡峭，進而導致載子的有效質量變輕，以其費米速度增快。 電荷密度波隨著不同溫度下的序化現象在材料中有著重要的地位，碲化銅是一個適合針對電荷密度波以及弱相關系統進行研究的材料，而在適當的條件下，動量解析電子能量損失光譜更可以助於我們瞭解材料內的物理現象以及計算重要的物理參數，我們期待在更多擁有豐富物理性質的材料上，利用動量解析電子能量損失光譜獲得更加有趣的實驗結果。; With the rapid advances discovery in various systems, quantum materials have aroused lots of attention in the field. Recently, topological semimetals featuring symmetry-protected crossing of linearly dispersing bands in the bulk electronic structure has gained growing attentions in the investigation of the electronic screening due to a finite density of states. Those unique material systems become interested with the concept of the matters susceptible to electronic ordering, where charge density waves (CDWs) are pervasive orders in the systems. The capability to probe the carrier density near the Fermi level inside the CDW systems in topological quantum matters allows a direct unveiling observation of the electronic structure. This Ph.D. thesis has been dedicated to the momentum-dependent electron energy loss spectroscopy (q-EELS) on probing the effective mass and the Fermi velocity without further experiment setup. The reduced effective mass and the enhanced Fermi velocity in our CuTe system with CDW order growing exhibits an inverse result to the usual CDW systems. A general introduction to the quantum materials and the charge response phenomena is presented in Chapter 1 and the experimental elucidation is addressed in Chapter 2. In Chapter 3, we show the q-EELS experimental result on the CuTe crystal, where we can obtain the effective mass and the Fermi velocity using the classical plasmon dispersion relation. We can simultaneously capture the effective mass and the Fermi velocity of the related, practically linearly dispersing electron and the counterpart of heavy-hole carrier. In Chapter 4, we show the temperature dependent q-EELS experiment across the transition temperature 335 K (TCDW, CDW transition temperature) to help to observe the change followed the CDW order growth. The effective mass of practically linearly dispersing electron relating to CDW gap opening is 0.28 m0 (m0, the electron rest mass) and the Fermi velocity is approximate 0.005 c (c, the speed of light) at room temperature. Following the CDW order growth, the electrons becomes lighter and moves faster by ~20% toward to 100 K. Thorough inspection below TCDW unveils the essential role of the increasing opening of the CDW gap. CuTe is a rich platform for the exploration of CDW and weak-coupled correlation physics with q-EELS as a useful tool for probing the associated fundamental properties.

2024-01-01T00:00:00Z 陳定睿 Ding-Rui Chen http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/96365 2025-01-06T17:33:22Z 2024-01-01T00:00:00Z

標題: 用於高效水分解的原子層電催化劑設計; Atomically engineered electrochemical catalysts for efficient water splitting. 作者: 陳定睿; Ding-Rui Chen 摘要: 可再生能源需求的增長引起了世界對於水分解反應（2 H2O → 2 H2 + O2）的高度興趣，也突顯了高效催化劑的重要性。二維（2D）材料，如二硫化鉬（MoS2）的邊緣，展現了匹配的ΔGH*並具有作為析氫反應（HER）催化劑的潛力，然而這些材料的動力學尚未完全理解和解決。 在本論文中，我們首先研究了以邊緣主導的超窄MoS2 奈米帶陣列的電化學反應動力學表現。然後，我們通過二維邊緣的凡得瓦（vdW）堆疊實現了多位點電催化，除了透過實驗和模擬結果確認了優良的HER 和OER（析氧反應）以及多位點間中間體的交換反應，我們還展現了十分良好的整體水分解反應效果。 為了研究邊緣主導的電化學反應動力學，我們首先開發了一種模板減法圖案化方法（TSPP）。該型態工程法使我們能夠建立長距離、高密度和高質量的基面超窄奈米帶陣列，充當探索邊緣主導電化學的實驗平台。小於30 奈米的奈米帶陣列在評估電化學特性時展現出增強的HER動力學。由光電催化測量和載流子傳輸模擬證明這些改進是由於從基面向邊緣位置的電荷轉移效率的提高所貢獻的。我們的結果展示了邊緣主導電催化在HER 中的潛力，並為奈米帶製造和奈米帶增強電化學提供了一種有望的策略。 接著，我們繼續擴展透過vdW 堆疊2D 邊緣實現多位點邊緣催化。透過結合實驗與模擬結合，我們證明了vdW 堆疊活性位點在HER 中表現出協同作用，並確認了相鄰位點之間的中間體交換。此外，我們的結果展示了HER 和OER 的增強效果，優於均質疊層材料。vdW 堆疊的多位點催化成功應用於中性水分解微反應器，並表現出卓越的性能。; The growing demand for renewable energy has sparked interest in water-splitting reactions (2H2O → 2 H2 + O2), highlighting the crucial role of high-performance electrocatalysis.Two dimensional (2D) materials such as Molybdenum Disulfide (MoS2) edges exhibit the best matched ΔGH* for hydrogen evolution reactions (HER) if their kinetics can be addressed and understood. In this thesis, we first investigated the electrochemical reaction kinetics of edge-dominated ultranarrow MoS2 nanoribbon arrays. Then, multi-site electrocatalysis was achieved through the van der Waals (vdW) stacking of 2D edges. In addition to confirming excellent Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER), as well as intermediate exchange reactions through experimental and simulation results, we also demonstrated excellent performance in the overall water splitting reaction. To investigate edge-dominated electrochemical reaction kinetics, we first developed a morphological engineering method called the templated subtractive patterning process (TSPP). This method enables us to establish a long-range, high-density, and high-quality basal plane ultra-nanoribbon arrays, acting as an experimental platform for exploring edge-dominated electrochemistry. Sub-30nm nanoribbons demonstrate significantly enhanced HER kinetics through assessed electrochemical characterizations. These improvements are due to increased charge transfer efficiency from the basal plane toward the edge sites as revealed by Photo-electrocatalytic measurements and carrier transport simulations. Our findings demonstrate the potential of edge-dominated electrocatalysis for HER and provide a promising strategy for nanoribbon fabrication and nanoribbon-enhanced electrochemistry. Afterward, we extended our exploration to realize multi-site edge catalysis by forming vdw 2D edges. Combining direct experimental evidence and Ab-initio simulations, we demonstrated that vdW stacking at active sites exhibits synergistic interactions in the HER, and the exchange of intermediates between neighboring sites was confirmed. Furthermore, our results showcased enhanced efficiency in HER and OER, outperforming homogeneous materials. The vdw stacked multi-site catalysis were successfully applied to neutral water-splitting microreactors, demonstrating superior performance.

2024-01-01T00:00:00Z 菲利普 Philip Anggo Krisbiantoro http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/94099 2024-08-14T16:41:15Z 2024-01-01T00:00:00Z

標題: 從塑料到高價值金屬有機框架材料：使用無溶劑研磨和烘焙法開發用於PET/PC回收和BHET/PET轉化為MOF的高性能催化劑; From Plastic to Valuable MOF Materials: Development of High-Performance Catalysts for PET/PC Recycling and BHET/PET-to-MOF Synthesis by Solvent-Free Grinding and Baking 作者: 菲利普; Philip Anggo Krisbiantoro 摘要: 開發一個塑膠回收和高值化應用的技術，以解決在過去半個世紀中因塑膠產量的大幅提升而日益惡化的全球塑膠污染，已是目前非常重要的議題。在本論文中，我們提出了以異相觸媒進行乙二醇解聚對苯二甲酸乙二酯(PET)和甲醇解聚碳酸酯(PC)的技術，並將PET乙二醇解後的產物聚對苯二甲酸乙二酯（BHET)當做配體以合成高價值的金屬有機框架(MOFs)。 在論文的第一部分中，我們使用機械化學合成法，在沒有溶劑的情況下成功合成四種尖晶石肥粒鐵(MFe2O4, M= Co, Ni, Cu, and Zn)以做為異相觸媒在常壓下乙二醇解PET。這四種尖晶石肥粒鐵在190 °C下皆具有良好的反應性並產出高純度的BHET，其中，他們的反應活性因為金屬離子的路易斯酸強度而可以排出以下結果：ZnFe2O4 > CuFe2O4 > CoFe2O4 > NiFe2O4。儘管CoFe2O4 在這些觸媒中的反應活性僅是第三佳，但其擁有的最高飽和磁化強度使它非常容易即可使用磁鐵和反應物分離。此外，它的反應活化能188 kJ mol–1也和目前文獻中異相觸媒的反應活化能相近。在實驗室規模的批次反應器中我們已可連續使用此觸媒至少五次，並透過Aspen Plus®軟體模擬證明這個乙二醇解技術在被放大後依然可行。 在論文的第二部分中，我們開發出一種以低成本且容易取得的鋁酸鈉做為觸媒來進行PC的甲醇解技術以得到高純度和高結晶度的雙酚A(BPA)單體。我們首先篩選了一系列的有機溶劑如丙酮、乙腈、氯仿、環己烷、二氯甲烷、碳酸二甲酯、庚烷、四氫呋喃(THF)，其中THF由於和PC有相似的極性而有最好的催化效果。在溶劑是THF的系統時，鋁酸鈉做為固態鹼性觸媒，其反應活性和溶解度很高的氧化鍶相當，並遠高於氧化鎂和氧化鈣。在60 °C與常壓下，鋁酸鈉可在2小時內達到98.1%的PC轉化率和96.8%的BPA產率，並且可重複進行此反應至少四次。同時，我們證明了反應機制是由甲氧基途徑進行，並且THF會使PC快速膨脹和溶解以加速反應。此外，在動力學分析上，使用鋁酸鈉做為觸媒僅有75.1 kJ mol–1的反應活化能，這是目前發表過的異相催化反應文獻中最低的數值。 在第三部分中，我們使用在第一部分中經由PET乙二醇解得到的BHET做為配體，並在沒有溶劑的情況下合成金屬有機框架。透過我們研發的“研磨和加熱”法可在不需溶劑的條件下以130 °C和30分鐘的反應時間合成UiO-66(Zr)，這比目前所有發表過的機械化學加熱法和溶劑熱合成方法都要快。此反應的反應機制是透過BHET水解產生的對苯二甲酸（BDC2−）陰離子和Zr簇的形成以合成出UiO-66(Zr)。此外，當我們將配體改成合成UiO-66(Zr)常用的對苯二甲酸，並使用相同的合成手法時，我們驚訝的發現不管是使用四氯化鋯或是氯氧化鋯做為鋯前驅物皆無法合成具高結晶度的UiO-66(Zr)。同時，我們也使用此技術合成出其他種類的MOF，如UiO-66(Hf)、Cu-BDC和MIL-53(Al)。與現有技術相比，本技術不僅實現了從廢PET到MOF的高值化轉化，還在更溫和的反應條件下同時兼顧環保。 第四部分做為第三部分的延續，我們發現將PET浸泡在乙二醇後 ，即可當做配體，並透過我們第三部分提到的研磨和加熱法來合成UiO-66(Zr)。此發現進一步證明了將PET直接轉化為MOF的可能性，讓廢PET轉化到MOF有更多可能。; Owing to the rapid upsurge in plastic production in the last five decades, which has resulted in a dramatic increase in global plastic pollution, the development of sustainable techniques for plastic recycling and upcycling is indispensable in an attempt to decrease global plastic pollution and to attain a sustainable cycle. In response to this, the present author performed the development of heterogeneous catalysts for the chemical recycling of polyethylene terephthalate (PET) via glycolysis and polycarbonate (PC) via methanolysis, and the conversion of PET and the glycolysis product of PET, namely bis(2-hydroxyethyl) terephthalate (BHET), into valuable metal-organic frameworks (MOFs). The first section covers the use of solvent-free mechanochemically synthesized spinel ferrite (MFe2O4, M= Co, Ni, Cu, and Zn) as a solid catalyst for PET glycolysis under atmospheric pressure. While all catalysts were active for the reaction at 190 °C, producing highly pure BHET, the catalytic activity over ZnFe2O4 > CuFe2O4 > CoFe2O4 > NiFe2O4. The difference in the catalytic activity among the catalysts was revealed due to the difference in the Lewis acid strength of the M2+, whereas the catalyst with the higher Lewis acid strength possessed higher catalytic activity. Although CoFe2O4 was the third-best catalyst in terms of catalytic activity, it exhibited the highest saturation magnetization, which is a great advantage for the magnetic separation of the catalyst. Over CoFe2O4, the reaction possessed an apparent activation energy (Ea) of 188 kJ mol–1, which is comparable to most reported heterogeneous catalysts for the reaction. While the catalyst was reusable at least five times, a simulation using Aspen Plus® revealed that scale-up is feasible. In the second section, PC methanolysis by using a low-cost and readily available sodium aluminate (NaAlO2) is presented. NaAlO2 was a highly active solid base catalyst for the reaction in the presence of tetrahydrofuran (THF) as a solvent, producing highly pure and crystalline bisphenol A (BPA) monomer, with the catalytic performance comparable to soluble SrO and much higher than those of MgO and CaO. Among tested organic solvents, e.g., acetone, acetonitrile (ACN), chloroform, cyclohexane, dichloromethane (DCM), dimethyl carbonate (DMC), heptane, and THF, THF was the best one in aiding the reaction owing to the polarity similar to the PC according to the Hansen solubility parameters (HSPs). At 60 °C and under atmospheric pressure, 98.1 and 96.8% of PC conversion and BPA yield, respectively, were achieved within just 2 h. While the catalyst can be reused for at least four runs, the mechanistic study revealed that the reaction was governed by the methoxide pathway, with THF aiding in the faster swelling and dissolution of PC. Over NaAlO2, the reaction exhibited Ea of 75.1 kJ mol–1, which is the lowest ever reported for a reaction over a heterogeneous catalyst. In the third section, the use of BHET (the glycolysis product of PET obtained from the first section) as a new linker source for the solvent-free synthesis of MOFs is highlighted. Via the solvent-free “grind and bake” technique, UiO-66(Zr) was easily synthesized. It was found that the hydrolysis of BHET to terephthalate (BDC2−) anion by proton produced from the hydrolysis and clustering of Zr precursor was the key to the crystal growth of UiO-66(Zr). Surprisingly, the use of H2BDC, which is a typical linker source for UiO-66(Zr), resulted in no and poor diffraction patterns of UiO-66(Zr) when ZrCl4 and ZrOCl2•8H2O, respectively, were used as Zr precursors. In this work, UiO-66(Zr) can be synthesized within 30 min (at 130 °C), which is much shorter than any previously reported mechanochemical-heating and solvothermal synthesis of UiO-66(Zr). Some MOFs, namely UiO-66(Hf), Cu-BDC, and MIL-53(Al), have also been successfully synthesized. This work realizes the idea of PET waste-to-MOFs with more convenience and green compared to the prior arts. The fourth section is the follow-up of the third section, where it was found that when PET is treated with ethylene glycol (EG), it can be used as a linker source for the grind and bake synthesis of UiO-66(Zr). This work demonstrates that direct conversion of PET into MOF is possible, further pushing the limit of PET-to-MOF conversion.

2024-01-01T00:00:00Z 劉佳燕 Chia-Yen Liew http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88635 2023-11-09T10:10:45Z 2023-01-01T00:00:00Z

標題: 使用邏輯演繹序列串聯質譜法鑑定碳水化合物的結構; Structural Determination of Carbohydrates by Using Logically Derived Sequence Tandem Mass Spectrometry (LODES/MSn) 作者: 劉佳燕; Chia-Yen Liew 摘要: 碳水化合物在生活中具有多種功能，它與蛋白質和去氧核糖核酸等其他生物大分子一樣重要。但是，我們對碳水化合物的瞭解遠遠落後於我們對蛋白質和核酸的瞭解相比。這主要是因為碳水化合物的結構分析是非常具有挑戰性。質譜法是一種高度靈敏的分析工具，適用於分析生物大分子。大多數常用的質譜法涉及碳水化合物的衍生化或僅識別碳水化合物結構的一部分。為了開發一種通用且方便使用的質譜法以用於確定碳水化合物的一級結構，我們開發了一種新的質譜法來識別未衍生化的寡糖的結構。這種方法，稱爲邏輯演繹序列串聯質譜法（LODES/MSn ），可以提供鎖鏈結構，異頭構型，單醣成分和分支位置。LODES/MSn 使用鈉離子加合物的低能量碰撞誘導解離 (CID)，從而能夠裂解選擇性化學鍵，這是為後續 CID 識別結構決定性碎片離子的合理解離序列，並且特別是製備了雙醣 CID譜的數據庫。這方法首先應用在各種標準寡糖，以證明方法的準確性。然後應用在從牛蛋白質、大豆蛋白、人乳腺上皮細胞中提取的 N-聚醣和高甘露糖 N-聚醣和人類乳腺癌。; Carbohydrates have various functions in life, they are as important as other classes of macrobiomolecules such as protein and DNA. However, our understanding of carbohydrates is far lagged behind compared to what we have learned protein and DNA. This is mainly because the structural analysis of carbohydrates is challenging. Mass spectrometry is highly sensitive and a robust analytical tool for macro-biomolecule analysis. Most of the commonly used mass spectrometry-based methods involve the derivatization of carbohydrates or only identify part of the carbohydrate structure. With the aim to develop a universal yet user friendly mass spectrometry-based method to determine the primary structure of carbohydrates/glycans, we developed a new method for complete structural identification of underivatized oligosaccharides. This method, logically derived sequence tandem mass spectrometry (LODES/MSn), can provide assignments of linkages, anomeric configurations, monosaccharide constituents, and branch locations. LODES/MSn entails low-energy collision induced dissociation (CID) of sodium ion adducts that enable the cleavage of selective chemical bonds, a logical procedure to identify structurally decisive fragment ions for subsequent CID, and the specially prepared disaccharide CID spectrum databases. This method was first applied to determine the structures of various types of standard oligosaccharides as a proof of concept. Then, we applied LODES/MSn to structural assignment of sialylated oligosaccharides, N-glycans, and high mannose N-glycans extracted from bovine whey proteins, soybean proteins, human mammary epithelial cells, and human breast carcinoma.

2023-01-01T00:00:00Z