二氧化鈦光觸媒是利用光能,經紫外光照射過後生成電子電洞對,與空氣中的水氣及氧氣產生氫氧自由基及超氧離子,可將吸附在光觸媒表面的有機物質分解。由於二氧化鈦具有高光學活性、高比表面積、高光催化效率、化學性質及熱性質穩定、耐光腐蝕等優點,被廣泛應用於水中有機汙染物的降解、室內空氣的淨化、抗菌、除臭等功用。商業用粉末狀奈米TiO2光觸媒顆粒細微,容易造成粉塵汙染,引起人體肺部發炎或纖維化的可能性,因此應用上需要二氧化鈦光觸媒的固定化技術。本研究選用奈米二氧化鈦水溶液,藉由浸塗及高溫燒結法,於非平面之立體基材如體表面積大的玻璃串珠和不鏽鋼網表面上進行二氧化鈦光觸媒鍍膜,使用SEM、EDX、XRD等儀器鑑定分析表面鍍膜情況,並利用紫外光(395nm)的光源照射,以亞甲基藍水溶液進行光催化降解實驗,作為二氧化鈦鍍膜於不同基材光催化活性分析的指標。
Titanium dioxide is a semiconductor which exhibits catalytic properties. The photo-catalytic process over a semiconductor involves the absorption, band gap excitation, separation of the photo-excited electron/hole pairs, and redox reactions on the semiconductor surface. Since titanium dioxide shows relatively high reactivity and chemical stability, it has been widely studied in environmental application as for organic vapour degradation, hydrogen production from water, deodorization and antibacterial. The commercial available photocatalyst TiO2 is the form of nano-powder which would cause inhalation and lung damage during exposure. Moreover, it also causes several post-degradation treatment problems in application, such as filtration, precipitation, etc. Therefore, it is important to develope the technique of TiO2 immobilization. In this dissertation, two non-planar substrates, glass beads and stainless steel mesh, were studied. The titanium dioxide films were coated by dip coating via nano TiO2 aqueous solution. Coating films were characterized by SEM, EDX, and XRD. The photo-catalytic efficiency of films were investigated via methylene blue aqueous solution under UV light (395nm).