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Title: | 合成碲化鐵與石墨烯奈米材料及其於感測和光催化之應用 Synthesis of Iron Telluride and Graphene based Nanomaterials for Sensing and Photocatalytic Applications |
Authors: | Prathik Roy 羅伊 |
Advisor: | 張煥宗 |
Co-Advisor: | 梁啟德 |
Keyword: | 鐵-碲奈米棒,類酵素活性,比色型生物感測器,毒理學,半導體型光觸媒,石墨烯-氧化鋅-金奈米複合體,硝基苯,環境復育, iron telluride nanorods,enzyme mimics,colorimetric biosensors,toxicology,semiconductor photocatalysts,graphene-ZnO-Au nanocomposites nitrobenzene,environmental remediation, |
Publication Year : | 2013 |
Degree: | 博士 |
Abstract: | 本論文主要是利用合成的奈米材料來偵測血液樣品中葡萄糖及汞離子濃度,且應用奈米材料之光觸媒活性進行高毒性污染物如硝基苯的降解。論文分成四個章節,第一章內容包括奈米材料作為感測器的背景簡介、以奈米材料類酵素活性的概念設計比色型生物感測器,及半導體型光觸媒應用於環境復育的介紹。第二章以電化學方法將碲奈米線合成具有類過氧化酶活性的碲化鐵奈米棒(FeTe nanorods)。當有過氧化氫的存在時,碲化鐵奈米棒對過氧化酶之受質-ABTS 具有極高的催化活性,此催化機制可應用於偵測過氧化氫及葡萄糖的濃度,對兩者的偵測極限和線性範圍分別是(55 nM;0.1-5 μM)和(0.38 μM;1-100 μM),其偵測效果優於其他由鐵所製備的奈米材料及辣根過氧化酶。而碲化鐵奈米棒的高催化活性推測可能是反應中鐵離子的釋出扮演重要角色。第三章是利用碲化鐵奈米棒與汞離子之間的陽離子交換反應,根據其顏色的變化,設計可偵測血液中汞離子的比色型生物感測器,其偵測極限為1.31 nM,訊雜比為3,線性範圍5-100 nM,顯示此系統對汞離子具有高度選擇性。在最後一章中,以簡便的水熱法合成石墨烯-氧化鋅-金的奈米複合體 (G-ZnO-Au NC),此材料在紫外光照射140 分鐘的條件下,可將硝基苯還原成苯胺,且產率高達98 %,相較於市售的二氧化鈦及氧化鋅奈米球,此複合體催化活性高於此兩種材料分別為3.5 及4.5 倍。此外,石墨烯-氧化鋅-金的奈米複合體在經過五次重覆反應後,其轉換效率只降低7%,顯示此材料具有極佳耐久性。研究石墨烯-氧化鋅-金的奈米複合體將硝基苯還原成苯胺的反應機制,數據顯示在無氧環境下,還原反應的效率可達到最高,其主要的原因可能是氧氣會競爭被光子激發的電子,進而影響材料的光催化活性。由於石墨烯-氧化鋅-金的奈米複合體光觸媒具有降解有毒污染物的特性,相信未來有極大的潛力應用於環境復育上。 This thesis focuses on synthesizing nanomaterials for sensing of glucose and mercury in blood, and photocatalysis of highly toxic pollutants such as nitrobenzene. My thesis is divided into four parts. Chapter one introduces the background of nanomaterials as sensors, the concept of enzyme mimics for colorimetric bio-sensing purposes, as well as an introduction to semiconductor photocatalysts, unique properties offered by photocatalytic nanomaterials for nvironmental remediation. In chapter two, iron telluride nanorods (FeTe NRs) were prepared from Te nanowires through a galvanic reaction, that act as enzyme mimics and possesses strong catalytic activity towards the oxidation of a peroxidase substrate (ABTS) by H2O2, enabling the detection of H2O2 and glucose with a limit of detection (LOD) of 55 nM (linear range = 0.1_5 μM) and 0.38 μM (linear range = 1_100 μM) respectively, which is better than other iron based nanomaterials and horse radish peroxidase (HRP). It is also found that the release of Fe2+ ions plays a critical role in the high catalytic activity. The third chapter utilizes the FeTe NRs based system for the detection of mercury with a limit of detection of 1.31 nM at a signal-to noise ratio of 3 and a linear range of 5 to 100 nM (R2 = 0.99), through a cation exchange reaction between FeTe NRs and Hg2+ as a colorimetric biosensor for total mercury in blood. The sensing system exhibits excellent sensitivity for mercury. The final chapter deals with the development of graphene-ZnO-Au nanocomposite (G-ZnO-Au NC) through a simple hydrothermal approach, which acts as a highly efficient photocatalyst under UV light for the reduction of nitrobenzene to aniline under 140 min with an yield of ca. 98 %. The photocatalytic activities of the nanocomposite are 3.5 and 4.5 fold higher than that of commercial TiO2 and ZnO nanospheres (NSs) respectively, it also exhibits excellent durability with a decrease of only 7% in the conversion efficiency after 5 cycles. A detailed study on the mechanistic path of the VIII photocatalytic reduction reveals that reduction of nitrobenzene to aniline is most efficient in the absence of oxygen, as oxygen tends to compete for the photo-generated electrons. G-ZnO-Au NC photocatalyst has the potential to find real world applications in the near future for environmental remediation. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/6206 |
Fulltext Rights: | 同意授權(全球公開) |
Appears in Collections: | 化學系 |
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