| Summary: | Luminescence of layered double hydroxide (LDH) has been the focus of much scholarly research and popular attention. The general common preparation methods of luminescence LDH：(1) Intercalated transition metal element；(2) The anion dye intercalated into LDH；(3) Doping the rare earth metals, etc. This study of Li-Al-CO3 LDH do not need to add transition metals, rare earth elements or other anion dye, just adsorption of carbon dioxide (CO32-) that is used as the interlayer anion have luminescent properties. Use Photoluminescence Spectrometer (PL) to measure the luminescence intensity of LDH after heat treatment at different temperature. Between room temperature to 300 °C, with the heat treatment temperature increase, the fluorescence intensity increase. Li-Al-CO3 LDH after 300 °C heat treatment, fluorescence intensity increased 10 times. The Li-Al-CO3 LDH after 300 °C, 400 °C heat treatment place into Temperature & Humidity Chamber (25 °C_65 %RH) and passing air flow rate of 20 (L/min) to maintain 28 days. The fluorescence intensity decreased of LDH after 300 °C, 400 °C heat treatment with holding time increase, to 7 days after the fluorescence intensity tends to a stable value, reasons for this phenomenon is the heat treatment remove the interlayer carbonate anions, with the increase of storage time, carbonate anions reply to interlayer region caused decrease in fluorescence intensity. However, this is still far higher than the fluorescence intensity of the non-heat treated Li-Al-CO3 LDH. The Li-Al-CO3 LDH after 300 °C heat treatment place into Temperature & Humidity Chamber (25 °C_10 %RH) and passing air flow rate of 20 (L/min) to maintain 28 days. With holding time increase fluorescence intensity smaller decline of LDH. The results suggest that in the interlayer carbonate anions will result in fluorescence intensity decrease of LDH. Because atmospheric carbon dioxide is soluble in water to form carbonic acid anion, in a high humidity environment will cause decrease fluorescence intensity of LDH. The Li-Al-CO3 LDH of luminescence band at 400 nm, expected to be applied to long-ultraviolet (UVA) the scope of application in the future. This Li-Al-CO3 LDH after 300 °C heat treatment has a unique fluorescent properties. The LDH were measured hydrogen evolution reaction (HER) with good catalytic effect of hydrogen evolution. Our lab will focus on this LDH-300 °C to improve process and parameters expected to be applied to the development of the cathode material in the future. 近年來層狀雙氫氧化物(LDH)在光學上的研究頗受矚目，而一般常見的LDH發光製備方法有插入有機染劑之陰離子做陰離子交換；插入過渡金屬元素至LDH夾層中；添加稀土元素的離子等。本研究開發之Li-Al-CO3 LDH，不需加入過渡金屬及稀土金屬元素或其他螢光物質，藉由吸附二氧化碳(碳酸根)作為陰離子即具有發光特性。使用光激發螢光光譜儀(PL)量測此LDH經由不同溫度熱處理後之螢光強度變化。熱處理溫度於300 °C之前，其螢光強度隨著熱處理溫度上升而增加，當LDH經過300 °C熱處理後螢光強度增強10倍。將Li-Al-CO3 LDH經300 °C、400 °C熱處理後放置於溫度25 °C，濕度65 %RH之恆溫恆濕試驗箱通入每分鐘20公升流量之空氣並放置28天。其中LDH經300 °C及400 °C熱處理後隨放置天數的增加而螢光強度下降，至7天後螢光強度趨於一穩定值，此原因為熱處理去除夾層內碳酸根陰離子，隨著放置時間的增加其碳酸根陰離子回復至LDH夾層中造成螢光強度下降，然而此螢光強度仍然遠高於未經熱處理之Li-Al-CO3 LDH。將此LDH經300 °C熱處理後放置於溫度25 °C，濕度10 %RH之乾燥環境並通入每分鐘20公升流量之空氣並放置28天，此LDH隨放置天數增加螢光強度下降的趨勢較小；本實驗結果顯示，夾層內碳酸根陰離子會造成LDH螢光強度下降而大氣中二氧化碳易溶於水中形成碳酸根陰離子，因此在高濕度的環境下會造成螢光強度明顯下降的現象。此Li-Al-CO3 LDH之發光波段為400 nm，未來可望應用於長紫外光(UVA)之應用範疇。由本實驗室開發之Li-Al-CO3 LDH經300 °C熱處理後具有獨特之螢光特性，將此LDH進行析氫催化反應量測具有良好之析氫催化效果；本實驗室後續將針對此LDH-300 °C進行製程及參數改良，未來可望應用於陰極材料之開發。 摘要 I ABSTRACT II 總目錄 IV 圖目錄 VI 第一章 前言 1 第二章 實驗步驟與方法 6 2-1 實驗基材前處理 6 2-2 鋰鋁離子電沉積液體配製 6 2-3 電化學裝置設備及製程 6 2-4 LDH粉末製程 7 2-5 LDH薄膜試片及粉末之熱處理 7 2-6 表面形貌及結構分析 8 2-7 傅立葉轉換紅外線光譜儀(FT-IR) 8 2-8 光激發螢光光譜儀及螢光顯微鏡 9 2-9 LDH陰極材料製程(HER量測) 9 第三章 實驗結果與討論 11 3-1 Li-Al-CO3 LDH薄膜及熱處理後之性質分析 11 3-2 Li-Al-CO3 LDH薄膜及熱處理後之螢光特性分析 12 3-3 LDH-300 °C其夾層CO32-陰離子與螢光強度之關係 13 3-4 LDH-400 °C其夾層CO32-陰離子與螢光強度之關係 15 3-5 乾燥環境下LDH-300 °C其夾層CO32-陰離子與螢光強度之關係 17 3-6 LDH-300 °C及LDH-400 °C之螢光強度關係 19 3-7 LDH陰極材料開發之析氫反應催化性質 20 第四章 結論 22 參考文獻 51
|
|---|