https://ir.lib.ncu.edu.tw/handle/987654321/337 Search the Channel s https://ir.lib.ncu.edu.tw/simple-search https://ir.lib.ncu.edu.tw/handle/987654321/99282 title: 沸石咪唑酯骨架衍生物支撐鉑鈷雙金屬觸媒應用於酸性介質中之高效析氫反應;ZIF-Derived Platinum-Cobalt Bimetallic Catalyst for Enhanced Hydrogen Evolution Reaction in Acidic Media abstract: 氫氣具高能量密度且零碳排放特性，為極具潛力的未來能源載體，而電化學水分解結合再生能源，被廣泛認為是生產綠氫的關鍵途徑。質子交換膜水電解(proton exchange membrane water electrolysis, PEMWE)具有高電流密度、高氫氣純度及快速響應等優勢。然而，其廣泛應用仍受制於對白金(Pt)觸媒的高度依賴。Pt的高成本與耐久性限制了PEM大規模部署，因此迫切需要開發低Pt用量且性能穩定的觸媒。 本研究設計了應用於酸性(0.5 M H2SO4)環境中的析氫反應(hydrogen evolution reaction, HER)電催化觸媒，利用沸石咪唑骨架(zeolitic imidazolate framework, ZIF)衍生多孔碳載體結合微量Co/NC負載成功製備了低負載Pt基電催化觸媒。ZIF-67衍生的多孔碳框架提供了開放通道結構，因其結構可有效限制Pt奈米粒子的團聚，同時提升活性位點暴露度並抑制結構劣化。再者，策略性調控Co-N-C位點可作為Pt的錨定中心，能 其分散負載並有效抑制Pt在反應過程中的溶解，結合上述同步提升催化活性、金屬利用率及穩定性。值得注意的是，Pt-Co/NC在酸性環境中表現卓越，在電流密度10 mA cm-2 下的過電位(η10)僅為6 mV，Tafel斜率為11 mV dec-1，質量活性高達3054 A g-1。為深入探討觸媒催化機制，進行了臨場X光吸收光譜(X-ray absorption spectroscopy, XAS)分析，剖析HER過程中Pt配位環境的變遷，同時利用電感耦合電漿發射光譜(inductively coupled plasma optical emission spectrometry, ICP-OES)分析穩定性測試後 Pt 的溶解程度。臨場XAS與ICP-OES結果顯示，ZIF-67衍生的多孔碳載體及Co-N-C錨定位點的協同效應，提供良好的結構穩定性，也有效抑制了Pt的團聚與溶解。在實際應用評估中，將 該觸媒當作陰極在PEMWE系統中進行測試，於1.72 V下達到1.0 A cm-2的電流密度，並在1 A cm-2下穩定運行超過20小時，凸顯其卓越的實際應用潛力。綜合以上，本研究為開發高活性與耐久性的低Pt負載HER觸媒設計提供了重要解方。;Hydrogen, featuring high energy density and carbon-free utilization, is widely regarded as a promising energy carrier for future sustainable energy systems. Among various hydrogen production technologies, electrochemical water splitting powered by renewable electricity has emerged as a key pathway for the generation of green hydrogen. Proton exchange membrane water electrolysis (PEMWE) offers advantages, including high current density, high hydrogen purity, and rapid dynamic response. However, its large-scale deployment remains severely constrained by the heavy reliance on platinum (Pt) electrocatalysts. The high cost and durability concerns associated with Pt necessitate the development of electrocatalysts with reduced Pt content while maintaining high activity and long-term stability. In this study, a low-Pt-loading electrocatalyst for the hydrogen evolution reaction (HER) in acidic media (0.5 M H2SO4) was designed by integrating a zeolitic imidazolate framework (ZIF) derived porous carbon support with low Co/NC loading. The porous carbon framework provides an open-channel architecture that effectively confines Pt nanoparticles, thereby suppressing aggregation, enhancing active site exposure, and mitigating structural degradation during operation. Moreover, the strategic modulation of Co-N-C sites serves as anchoring centers for Pt, promoting uniform dispersion and effectively suppressing the dissolution of Pt during HER. This synergistic design simultaneously enhances catalytic activity, Pt utilization efficiency, and structural stability. Notably, the Pt-Co/NC exhibits outstanding HER performance under acidic conditions, delivering an ultralow overpotential of only 6 mV at 10 mA cm-2 (η10), a small Tafel slope of 11 mV dec-1, and an exceptionally high mass activity of 3054 A g-1. To gain deeper insights into the catalytic mechanism, in-situ X-ray absorption spectroscopy (XAS) was conducted to elucidate the dynamic evolution of coordination environments of Pt during HER, while inductively coupled plasma optical emission spectrometry (ICP-OES) was employed to quantify the degree of Pt dissolution after durability tests. The combined in-situ XAS and ICP-OES results reveal that the synergistic effects of the ZIF-67-derived porous carbon support and Co-N-C anchoring sites provide excellent structural stability, effectively suppressing Pt aggregation and dissolution. For practical evaluation, the Pt-Co/NC was further employed as the cathode in a PEMWE device. The electrolyzer achieves a current density of 1.0 A cm-2 at a cell voltage of 1.72 V and maintains stable operation for over 20 h at 1 A cm-2, demonstrating its practical applicability. Overall, this work provides an effective strategy for the rational design of highly active and durable low-Pt loading HER electrocatalysts. <br> https://ir.lib.ncu.edu.tw/handle/987654321/99280 title: 鎳-銅-鉬/1-T MoS2複合電極之MAGE製備及其在1.0 M KOH電解水產氫之陰極效能;MAGE Fabrication of a Ni-Cu-Mo/1T-MoS2 Composite Electrode and Its Cathodic Performance for the Hydrogen Evolution Reaction in 1.0 M KOH abstract: 本研究首先以實驗室研發的微陽極導引電鍍法(Micro-anode guided electroplating，MAGE) 來製備鎳銅鉬(Ni-Cu-Mo)合金微柱，並測量其在鹼性環境下陰極析氫的效能，並在後續另外利用水熱法來合成1T相二硫化鉬(1T-MoS2)粉末，並將合成出的1T相二硫化鉬粉末加入先前最佳配方之鎳銅鉬合金微柱鍍液中，並同樣利用微陽極導引電鍍法製備鎳銅鉬/二硫化鉬(Ni-Cu-Mo/1T-MoS2)微柱，來比較兩者的效能差異。 而所製備的鎳銅鉬合金微柱與鎳銅鉬/二硫化鉬微柱會分別進行微柱特分析與微柱效能分析，使用掃描式電子顯微鏡(SEM)觀察表面形貌、能量色散X射線光譜(EDX)進行表面成分分析，以及利用X射線繞射(XRD)與穿透式電子顯微鏡(TEM)進行晶體結構鑑定分析。而微柱效能分析則包括線性掃描伏安法(LSV)、循環伏安法(CV)、計時電位法(CP)、電化學活性表面積(ECSA)與電化學阻抗頻譜(EIS)等電化學測試。 研究結果顯示，添加1T-MoS2所製備的複合微柱，其HER效能顯著優於合金微柱。當複合微柱之最佳成分約為Ni 33 at.%、Mo 24.9 at.%、Cu 29.8 at.%、S 12.3 at.% 時，其表面呈現具高表面積的類多孔海綿狀結構。此複合微柱展現了最佳的電化學析氫性能：塔弗斜率(Tafel slope)僅為42.5 mV/dec；在10 mA/cm2的電流密度下，僅需37 mV 的過電位(ƞ10)；陰極峰值電流密度來到1932 mA/cm2；且電荷轉移電阻(Rct)低至 1.87 Ω∙cm2。 這些結果證實了Ni-Cu-Mo/1T-MoS2複合微柱在鹼性環境下具有卓越的析氫能力。本研究認為，1T-MoS2的引入促使微柱形成奈米晶結構，大幅增加了電化學活性表面積 (ECSA)；並且金屬特性的1T相MoS2提供了豐富的反應活性位點。二者協同作用故顯著提升了HER效能，為高效、低成本的氫氣生產提供了具潛力的電催化劑。 ;In this study, Nickel-Copper-Molybdenum (Ni-Cu-Mo) alloy micropillars were first fabricated using a lab-developed Micro-anode guided electroplating (MAGE) method, and their cathodic hydrogen evolution reaction (HER) performance in an alkaline environment was evaluated. Subsequently, 1T-phase Molybdenum Disulfide (1T-MoS2) powder was synthesized via a hydrothermal method. This synthesized 1T-MoS2 powder was then added to the previously optimized Ni-Cu-Mo alloy plating bath, and Ni-Cu-Mo/1T-MoS2composite micropillars were fabricated using the same MAGE technique to compare the performance differences between the two.Both the prepared Ni-Cu-Mo alloy and Ni-Cu-Mo/1T-MoS2 composite micropillars underwent comprehensive material characterization and electrochemical performance analysis. Characterization involved scanning electron microscopy (SEM) to observe surface morphology, energy-dispersive X-ray spectroscopy (EDX) for surface composition analysis, and X-ray diffraction (XRD) and transmission electron microscopy (TEM) for crystal structure identification. The electrochemical performance was evaluated through linear sweep voltammetry (LSV), cyclic voltammetry (CV), chronopotentiometry (CP), electrochemical active surface area (ECSA) assessment, and electrochemical impedance spectroscopy (EIS).The results reveal that the composite micropillars prepared with the addition of 1T-MoS2exhibited significantly superior HER performance compared to the alloy micropillars. The optimal composite, with a composition of approximately Ni 33 at.%, Mo 24.9 at.%, Cu 29.8 at.%, and S 12.3 at.%, displayed a high-surface-area, porous, sponge-like morphology. This composite micropillar demonstrated exceptional electrochemical HER performance: a Tafel slope of only 42.5 mV/dec, an overpotential (ƞ10) of just 37 mV required to achieve a current density of 10 mA/cm², a cathodic peak current density reaching 1932 mA/cm2, and a low charge transfer resistance (Rct) of 1.87 Ω∙cm2.These results confirm the outstanding HER capability of the Ni-Cu-Mo/1T-MoS2 composite micropillars in alkaline media. This study suggests that the incorporation of 1T-MoS2 promotes the formation of a nanocrystalline structure, thereby significantly increasing the electrochemical active surface area (ECSA). Moreover, the metallic 1T-phase MoS2 provides abundant reactive active sites. The synergistic effect of these factors leads to a remarkable enhancement in HER performance, presenting a promising electrocatalyst for high-efficiency, low-cost hydrogen production. <br> https://ir.lib.ncu.edu.tw/handle/987654321/99278 title: 非對稱金屬接觸之MoS₂蕭特基二極體電性及光響應性能之探討;Investigation of Electrical and Photoresponse Characteristics of MoS₂ Schottky Diodes with Asymmetric Metal Contacts abstract: MoS₂ 因其獨特的能帶結構與優異的光學性質，近年來成為極具研究價值的光電材料。單層 MoS₂ 為直接能隙半導體，能隙約為 1.8 eV，對可見光範圍具有強烈的吸收能力；而多層 MoS₂ 則轉變為間接能隙結構，能隙降至約 1.2 eV。這種能帶的可調控性使 MoS₂ 能涵蓋從可見光至近紅外的吸收範圍，提升其於多波段光偵測中的應用。此外，透過高功函數金屬與MoS₂ 形成的Schottky 接觸，具備內建電場及低暗電流的優勢，使其在光電轉換效率上表現出優異的光響應特性。 在本研究中，我們採用 VLS 法生長單層 MoS₂ 薄膜，並選擇鉍金（Bi/ Au）及低溫度下沉積金（Au）作為兩端金屬電極，製作出非對稱電極結構的 MoS₂ 蕭特基二極體。藉由低損傷的金屬沉積製程，可有效降低費米能階釘扎效應（Fermi level pinning），進而提升蕭特基能障高度（Schottky barrier, SB）。實驗結果顯示，所製作之元件展現出明顯的整流行為，整流比達156。 在光電特性方面，該元件於照光條件下能穩定產生的光電流，顯示出明確的光響應特性。進一步在入射光功率為0.89mW/cm2與反向偏壓為-1V條件下進行量測，計算出元件的光響應度最高為 3.41 A/W，偵測度為 4.61 × 10¹¹ Jones，顯示本元件具有優異的光偵測性能，具備作為二維光偵測元件的應用潛力。 ;Due to its unique band structure and excellent optical properties, MoS₂ has emerged in recent years as a highly valuable material for optoelectronic research. Monolayer MoS₂ is a direct bandgap semiconductor with a bandgap of approximately 1.8 eV, exhibiting strong absorption in the visible-light range, whereas multilayer MoS₂ transitions into an indirect bandgap structure with a reduced bandgap of about 1.2 eV. This tunable band structure enables MoS₂ to cover an absorption range from visible to near-infrared light, thereby enhancing its potential for multispectral photodetection. In addition, the Schottky contact formed between high-work-function metals and MoS₂ provides the advantages of an intrinsic built-in electric field and suppressed dark current, thereby enabling superior photoresponse characteristics in terms of optoelectronic conversion efficiency. In this study, monolayer MoS₂ films were grown using the VLS method, and asymmetric Schottky diodes were fabricated by employing bismuth/gold (Bi/Au) and low-temperature-deposited gold (Au) as the two metal electrodes. By adopting a low-damage metal deposition process, the Fermi level pinning effect was effectively suppressed, thereby enhancing the Schottky barrier height (SB). Experimental results demonstrated that the fabricated devices exhibited pronounced rectifying behavior with a rectification ratio of 156. In terms of photoelectric characteristics, the device generates stable photocurrents under illumination, exhibiting a distinct photoresponse behavior. Further measurements conducted under an incident optical power density of 0.89 mW/cm² and a reverse bias of −1 V revealed a maximum photoresponsivity of 3.41 A/W and a detectivity of 4.61 × 10¹¹ Jones, indicating that the device possesses excellent photodetection performance and holds great potential for applications as a two-dimensional photodetector. <br> https://ir.lib.ncu.edu.tw/handle/987654321/97732 title: 脈衝雷射沉積技術於薄膜質子傳導型固態氧化物燃料電池陰極之應用;Application of Pulsed Laser Deposition Technique in the Cathode of Thin-Film Proton-Conducting Solid Oxide Fuel Cells abstract: 因其具有熱膨脹不匹配顯著減弱，可提高使用壽命；啟動速度提升，適合小型、分散式發電，以及材料選擇種類增加等優點，中溫質子傳導型的研究蓬勃發展。然而，操作溫度的降低會影響氧還原反應 (Oxygen reduction reaction, ORR)的速率。 本研究使用脈衝雷射沉積取代傳統的刷塗，製作出由奈米顆粒堆積且具有高孔隙率的Gd0.3Ca2.7Co3.82Cu0.18O9-δ (GCCCO)陰極。以刷塗方法製作的陰極受限於粉末顆粒，比表面積相對較大，有著較大的厚度，且平整度較差。以脈衝雷射沉積製作陰極，雷射能量瞬間使靶材局部溫度劇升，使材料汽化並電離，形成包含原子、離子、電子及小團簇的高溫高速羽流（plume），撞擊並沉積到基板表面。羽流中的粒子在基板上冷卻、成核並層層堆積，更小的晶粒構成的團簇有著較高的反應面積，降低了全電池量測中的極化阻抗，尤其在高頻的部分。 由脈衝雷射沉積陰極，並以700℃進行退火處理。製成的全電池在600℃的操作溫度下，峰值功率密度達937 mW/cm2，極化阻抗為0.102 Ω•cm2。比較兩種全電池的差異，證實了脈衝雷射沉積形成的陰極微結構能夠顯著提升全電池的性能。本實驗也比較了脈衝雷射退火、微波退火對電池性能的影響。 ;Because a sharply reduced thermal‑expansion mismatch extends service life, faster start‑up enables small‑scale and distributed power generation, and a wider palette of compatible materials becomes available, research on intermediate‑temperature proton‑conducting SOFCs has flourished. However, lowering the operating temperature inevitably slows the oxygen‑reduction reaction (ORR) at the cathode. In this study, pulsed laser deposition (PLD) replaced the conventional brush‑painting method to fabricate a highly porous Gd₀.₃Ca₂.₇Co₃.₈₂Cu₀.₁₈O₉₋δ (GCCCO) cathode built from nanoparticles. Brush‑painted cathodes are limited by powder particle size, giving lower specific surface area, greater thickness, and poorer flatness. During PLD, nanosecond laser pulses instantaneously heat the target, vaporizing and ionizing the material into a high‑temperature, high‑velocity plume of atoms, ions, electrons, and small clusters that strike the substrate. These species cool, nucleate, and stack layer by layer; clusters composed of finer grains provide a larger reactive surface, which lowers the cell’s polarization resistance—especially in the high‑frequency region of the impedance spectrum. After annealing the PLD cathode at 700 °C, the resulting single cell delivered a peak power density of 937 mW cm⁻² at 600 °C with a polarization resistance of 0.102 Ω cm². Comparing the two cell architectures confirms that the PLD‑derived cathode microstructure markedly boosts overall performance. The study also evaluates how pulsed‑laser annealing (PLA) and microwave annealing (MWA) affect cell performance. <br>