全國中小學科展

化學

化學液相沉積法製作摻鋁氧化鋅奈米線於染料敏化太陽能電池之研究

研究使用化學液相沉積法製作摻鋁氧化鋅(Zn1-xAlxO,x=0、2%、4%、6%)奈米線於染料敏化太陽能電池上,研究摻鋁氧化鋅奈米線之晶體結構、光學及染料敏化太陽能電池特性。結果顯示摻鋁濃度4%之氧化鋅奈米線具有最佳(002)結晶相及奈米線直徑及長度,也具有最佳太陽能參數為:開路電壓0.683V、短路電流4.56mA、填充因子52.3及轉換效率1.62%。因為鋁離子取代鋅離子時,可改變氧化鋅晶格結構降低缺陷密度,使奈米線的直徑及長度增加,提升染料的吸附量,並降低能隙使電子與電洞復合機率降低,大幅提升光電轉換效率。然而摻雜過量的鋁離子6%時反而導致晶格產生扭曲,導致晶格內缺陷密度增加。從這研究可了解摻雜鋁元素對於氧化鋅奈米線之染料敏化太陽能電池影響,未來希望能研究其他參數進而改善染料敏化太陽能電池之發電效率。

金屬多酚配位奈米載體合成與多功能腫瘤治療法開發

本研究結合奈米合成技術與生物醫學, 利用表沒食子兒茶素沒食子酸酯 (Epigallocatechin gallate, EGCG) 作為載體 調控摻雜Cu2+/Cu3+與 Fe2+/Fe3+之含量 並以π-π交互作用力附載缺氧性抗癌藥物替拉扎明 (Tirapazamine, TPZ) 成功製備出多功能金屬多酚配位奈米顆粒簡稱為EFeCuTPZ。 材料經紫外-可見光譜 (UV-vis),、動態光散射 (DLS) 及掃描式電子顯微鏡 (SEM) 確認其粒徑大小、形貌學與穩定性。利用808 nm和671 nm雷射分析其光熱轉換效率 評估光熱療法效果,。在腫瘤微酸性環境下, EFeCuTPZ可利用高濃度之H2O2行芬頓反應 (Fenton Reaction) 產生高活性之氫氧自由基 (•OH), 展現化學動力療法 (Chemo dynamic-therapy, CDT),。同時, 藉由材料中的Cu²⁺與腫瘤環境中的穀胱甘肽 (Glutathione, GSH)反應減少高活性物質 (Reactive oxygen species, ROS) 的消耗 增強CDT之療效。酸性條件下 TPZ顯著釋放 有助於腫瘤治療。 另外, 細胞實驗顯示EFeCuTPZ具有高生物相容性與治療效果, 成功開發出具CDT,、CT及PTT功能之奈米複合材料 為醫學新興藥物材料提供可能性。

開發回收PET合成UiO-66並應用於催化合成羥甲香豆素

本研究利用乙二醇處理後的聚對苯二甲酸(PET)及氯氧化鋯,以創新的無溶劑方式”solvent-free PET-to-MOF conversion”合成一類金屬有機框架材料(MOF) ── UiO-66(Zr),並發現此材料可用於催化Pechmann condensation、以間苯二酚和乙醯乙酸乙脂合成羥甲香豆素。於190℃之環境下,乙二醇處理6小時的EG-PET可合成出晶型最接近模擬模型的UiO-66晶體;而我們開發的合成方法中,最佳的反應條件為反應物質量比(氯氧化鋯:PET)= 2:1、130℃合成24小時。 對於合成出的UiO-66(Zr),我將其進行了XRD、FTIR、BET、SEM檢測,結果符合UiO-66(Zr)的特徵;唯比表面積僅有約900 平方公尺/克,推測此方法合成出的材料之有機linker數量和一般UiO-66(Zr)有所差異。 對於催化合成羥甲香豆素之反應,我們首先發現UiO-66(Zr)可作為非勻相催化劑參與此反應;且實驗結果顯示,相較於溶劑熱合成的UiO-66(Zr),以本研究的方法所得之UiO-66(Zr)作為催化劑可得到更高產率的羥甲香豆素。

Greenhouse Gases Reduction: Conversion of Methane and Carbon Dioxide into Clean Energy

In the upcoming years, both population and energy consumption are expected to increase dramatically [1]. Industrialization has led to a dramatic shift in the energy environment [2], with predictions of a 57% increase in demand for energy between 2002 and 2025 [3]. In addition to organic materials like trees and solid waste, fossil fuels like coal, natural gas, and oil provide more than 90% of the world's energy needs. Their overuse has resulted in the release of climate-altering greenhouse gases like carbon dioxide (CO2) and methane (CH4) into the atmosphere [4]. Scientists and other stakeholders are putting more emphasis on finding solutions to global warming, increasing energy production in order to meet increasing demands, and decreasing emissions of greenhouse gases. Using greenhouse gasses to make useful chemicals or fuels is one solution to both problems [5]. This motivated researchers to investigate the potential of CO2 and CH4 as clean energy sources. The process of dry reforming of methane (DRM) has been identified as a potentially successful strategy for transforming CO2 into marketable syngas with a balanced H2/CO composition [6], [7], [8], [9]. The economic viability of DRM, the reactor type, the availability of raw materials, and the intended use of the produced syngas are all-important considerations. Though DRM is gaining popularity, maintaining its long-term stability is difficult due to carbon accumulation from CO disproportionation and methane degradation [10], [11]. The catalyst used, as well as other parameters like as pressure, temperature, feed concentration, and reactor size, are critical to the process's effectiveness. In this scenario, a nickel catalyst on a La2O3/SiO2 substrate with microspheres and a core-shell structure will be developed to improve the conversion of greenhouse gases into profitable syngas. This catalyst is projected to improve the efficiency and performance of the DRM process significantly.

一價銠金屬催化肉桂胺衍生物進行不對稱氫芳基化反應 Rhodium(I)-Catalyzed Asymmetric Hydroarylation of Cinnamylamine Derivatives

一價銠金屬催化反應已經被廣泛應用於有機化學合成領域中。而本研究以具保護基之肉桂胺衍生物1與四芳基硼鈉試劑2a作為起始物進行銠金屬不對稱氫芳基化催化反應,得到具有保護基的掌性2,3-雙芳基丙胺衍生物3,並探討此反應的掌性雙烯配基對於反應的影響。本研究已完成使用Ts(對甲苯磺醯基)保護基之肉桂胺衍生物1a作為起始物進行反應,並改變與銠金屬錯合的配基,發現當配基使用2,5號位為芳基取代之配基L(掌性雙環[2,2,1]雙烯配基)時,反應有較好的位置選擇性,其中最佳的是芳基取代為苯基之配基L1,其位置選擇性比例為1:0:0.09。目前將進行改變起始物1之氮上的保護基,以L1作為配基進行反應,並與1a比較,優化反應性及產率。

Application of Carbon Aerogels in Lithium-Air Batteries

One of the main challenges with today’s batteries is their relatively low volumetric and specific capacities. The highest specific capacity can be achieved with lithium-air batteries, which use metallic lithium as the anode and typically some form of porous carbon as the cathode. To enhance performance, aerogels—among the world’s lightest solid materials—are ideal candidates for cathodes. Resorcinol-formaldehyde (RF)-based carbon aerogels, for example, serve this purpose well. In my work, I utilized two types of carbon aerogels as cathode materials: one derived from pyrolyzed resorcinol-formaldehyde polymer and the other a graphene-oxide-modified version of this carbon gel. I integrated the carbon aerogels I had pyrolyzed into lithium-air batteries to improve the cell’s performance, energy density, and capacity compared to cells using activated carbon. In my research, I examined the pore structure and surface properties of these materials in aqueous media using NMR (nuclear magnetic resonance) relaxometry and cryoporometry, exploring their impact on battery efficiency. I found that the graphene-oxide-containing sample's pores filled with water in a layered manner, indicating a more hydrophilic surface, which suggests a denser arrangement of oxygen-containing functional groups compared to the unmodified carbon aerogel. The pore sizes were reduced after adding graphene oxide, resulting in an increased specific surface area for the sample. Incorporating the reduced graphene-oxide-containing carbon aerogel enabled the creation of a more efficient, higher-capacity battery than with the RF carbon aerogel. This improved performance is likely due to the aerogel’s higher oxygen content and altered morphology. The increased oxygen content provides more active sites for oxygen reduction, meaning that a greater specific power output can be obtained from the battery.

複合葡萄糖氧化酶的金奈米團簇應用於葡萄糖檢測

本研究使用牛血清白蛋白(BSA)、穀胱甘肽(GSH)、金離子合成金奈米螢光團簇,並修飾上葡萄糖氧化酶(GOx)。此金奈米團簇上的葡萄糖氧化酶與葡萄糖反應,製造出過氧化氫,改變金奈米螢光團簇表面特性使螢光強度減弱,偵測葡萄糖濃度。 本研究探討不同條件金奈米團簇和不同濃度的葡萄糖反應,知道此材料可檢測到最低濃度的葡萄糖,且金奈米團簇在血液中對葡萄糖具有專一性,可穩定進行血糖檢測。另外,與不同濃度的人體血清樣本反應,發現血清濃度越高的螢光訊號下降明顯,因此可知修飾上葡萄糖氧化酶的穀胱甘肽輔助之牛血清白蛋白金奈米團簇(BSA/GSH-Au NCs)可用於人體血糖檢測。本研究開發出靈敏、快速、穩定的葡萄糖檢測材料,並期待未來能運用於實際的人體血糖檢測上。

二氧化鋯量子點在文物修復與減碳科技應用的潛力

本研究成功以水熱法在 110°C 下合成了約3.90 nm 大小的ZrO2量子點(QDs)。此設計的ZrO2 QDs 能隙為5.03 eV(波長λ < 300 nm),在可見光和紫外光範圍內無明顯吸收特徵,呈現高度惰性和穩定性,適合應用於抗紫外線塗層或顏料。而ZrO2 QDs 表面豐富的氧空位與不同溫度下的CO₂轉化率及CO/CH₄產物選擇性相關。氧空位為帶部分正電的酸性活性位,CO2作電子受體為路易士酸。經氧氣環境加熱處理後的ZrO2 QDs 能提高CO2轉化率且在低溫條件下選擇性較高能促進電子轉移生成CH₄(每分子8e⁻ 轉移)。不同金屬簇(如Fe、Ni、Co和Cu)表面修飾後,Fe-ZrO2 QDs 被證明為最佳催化劑,低溫下更有效促進CH₄生成,且優於ZrO2 QDs。這顯示Fe與ZrO2間存在顯著的強金屬-載體相互作用(SMSI),提升Fe捕捉CO₂分子的能力。此特性突顯ZrO2於碳減排技術的潛力,能有效將CO₂轉化為可再利用的碳基燃料或化學原料,為減少溫室氣體提供實用解決方案。

Utilization of Nano cellulose from date palm waste for improvement of thermal stability in epoxy composite

Nano additives is becoming popular trends nowadays due to its nanosize (1-100 nm). Incorporating nano additives in polymer could increase different properties such as mechanical, physical, electrical and thermal stability (1, 2). Different nano additives has been used such as nano copper oxide, nano silica, nano zinc oxide, nano titanium dioxide but most of these come from synthetic or metal oxides that considered as non-environmentally friendly and harmful to human when exposed or inhaled (3). One of the green materials that become attention by researchers is nano cellulose. Nano cellulose can be extracted in different methods and sources such as from wood, and non-woody resources such as kenaf, jute, bamboo as well as from bacteria such as Acetobacter species(4). This making nano cellulose abundantly available in resources. Nano cellulose can be in the form of nano crystalline cellulose (CNC) or NCC or can be in form of nano fibrillated cellulose (NFC) and bacterial nanocellulose (BNC)(5). This nanocellulose has many advantages that can give improvement in different applications such as mechanical, physical, thermal and improving the biodegradation when added together in different matrices (6, 7). Polymers have a problem in thermal stability while processing. It hard to control and maintain the thermal stability of polymer during processing and most polymers considered to have low in thermal stability except for thermosetting polymers such as epoxy. Epoxy has been widely used in many fields such as coating, adhesive, laminates, castings and many more (8). But the drawbacks of epoxy while using is hard to maintain and controll the thermal properties when processing of this materials and used for long period due to aging and attack by free radicals causing by UV radiation (9, 10). In this study we are incorporating nano additives into epoxy as polymer matrix to enhance and improve the thermal stability of composite by crosslinking the polymer chains with the nano additives. Furthermore, the nano additive used is come from nano cellulose extracted from date palm waste and thus to create an environmentally friendly and sustainable nano additives products.

Fabrication of Tandem Dye-Sensitized Solar Cells to Enhance Photovoltaic Performance

Energy has had an enormous impact on the development of technology and is a main factor in humans’ advancement towards an evolved society. Nevertheless, nonrenewable energy resources – which are the most effective in everyday application - have led to changes in the climate, environment, human health, and the world in general [1], which has encouraged researchers to switch to the use of renewable energy sources. Solar Cells are one of the most effective resources that rely on renewable energy. They come in a variety of types, operation methods, and efficiency as shown in Figure 1, including Dye-Sensitized Solar Cells (DSSC), which, inspired by photosynthesis in plants, uses photo-sensitive dye to capture sunlight and generate electricity. DSSCs were proved to have generated a great deal of interest and are one of the most promising solar cells among third-generation PV technologies, due to their low cost, simple preparation, good performance, and environmental friendliness compared to conventional photovoltaic devices [3]. However, their efficiency is quite insufficient for everyday use. Previous studies proved that Tandem DSSCs – which are two dye-sensitized cells stacked on top of each other – are able to enhance cell performance. The light absorption range of a tandem cell is increased because the bottom cell behind the top one absorbs and uses the incident light that was not absorbed by it [4]. It operates as shown in Figure 2, where the light photons excite the electrons of the dye molecules. The electrons are then transported to the FTO (conductive glass) by the semiconductor, which is used in the figure as TiO2 nanoparticles. The electrons pass through the circuit to perform the work, then move to the counter electrode (shown as Platinum). They are then transported by the electrolyte (I-/I3-) back to the dye molecules, and the process is repeated.