- 學位論文
中孔洞氧化矽材吸附與光催化行為之研究
The investigation of sorption and photocatalytic behavior of mesoporous silica material: SBA-15
摘要
本研究主要針對中孔洞氧化矽材於染料和二氧化碳處理之應用，首先自行合成有序規則排列之中孔洞氧化矽材(mesoporous silica, SBA-15)，將過渡金屬（鈦）引入材料內，讓材料具有催化活性，可解決傳統奈米級二氧化鈦使用上所面臨的分散化與回收等問題；再將貴重金屬（鉑）或具有輻射致效之稀土元素（鈰）披覆在含有鈦之複合材料表面，增加其催化活性以及擴展光源應用範圍。另外也嘗試將鹼土金屬（鈣）披覆在SBA-15上做為吸附二氧化碳之活性擔體，利用SBA-15優良的結構特性來強化氧化鈣在多次循環操作下結構的穩定性。所有經過高溫鍛燒後得到之功能性複合材料均利用分析儀器建立材料之物化性質與性能，例如：利用ICP分析材料成份組成；利用XRD分析晶相結構；以氮氣等溫吸/脫附實驗了解表面特性變化；以SEM探討其表面形貌變化；利用TEM觀察其孔洞與孔道結構…等等。另外本研究也建立吸附與催化等實驗裝置，探討自行製備的中孔洞氧化矽複合材料對於染料吸附與光催化降解之性能，以及二氧化碳捕集的能力。 本研究發展出兼具吸附及光催化功能之複合材料，利用其協同效應可以有效將環境中的染料吸附然後在實驗室中完全分解，達到材料再生進而再利用的效果。此外，披覆氧化鈣之複合材料可以在中高溫環境中有效吸附二氧化碳，且經過多次循環使用後仍維持不錯的效率和結構穩定性。
並列摘要
The purpose of this research is to study the dye removal and carbon dioxide capture by mesoporous silica. In this work, the textual and structural properties of all prepared materials are characterized by inductively coupled plasma-mass spectrometer (ICP-MS), powder X-ray diffraction (XRD) patterns, nitrogen physisorption isotherms, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In the beginning, highly ordered mesoporous silica, Santa Barbara Amorphous-15 (SBA-15), and titanium-substituted mesoporous silica (TiSBA-15) materials were synthesized, characterized, and evaluated. In terms of adsorption properties, the performance is examined by adsorption of dyes on SBA-15 and TiSBA-15 materials which are validated to be effective adsorbents for cationic dyes. In terms of photocatalytic properties, the performance is examined by photocatalytic degradation of dyes on TiSBA-15. It’s indicated that TiSBA-15 possess the synergistic effect of adsorptive and photocatalytic ability. The regeneration and cyclic performance is also prospective. These results revealed that TiSBA-15 has much potential to be one effective alternative material for dye removal. Furthermore, platinum and cerium ions are photodeposited onto TiSBA-15 powders in order to improve photocatalytic performance or induce radio-sensitive effect in the degradation of dye. On the other hand, calcium ions are dispersed onto mesoporous silica using impregnation method. The thermo-gravimetric analysis is used to test the performance of carbon dioxide capture using prepared calcium-based sorbents. The property and carbon dioxide sorption ability of the substrates and sorbents are examined and discussed. It is demonstrated that carbon dioxide can be effectively adsorbed, concentrated, and separated using the reasonable reaction paths. The long-term durability of prepared sorbents is also confirmed by carbon dioxide sorption/desorption cycle test under high temperature.