本研究係以浸鍍法製備銀改質二氧化鈦薄膜，期望以簡易的方式製備出具有光誘導親水性的光觸媒薄膜，藉由參數的調整，找出最適當的銀摻雜量，並進一步探討光觸媒薄膜之親水機制及自我潔淨之應用。
實驗中先找出二氧化鈦溶膠濃度及薄膜鍛燒溫度之最佳參數，再進行製備不同銀含量之二氧化鈦薄膜，進一步進行物性分析及光催化活性與光誘導親水性測試，找出其物性與光催化活性及親水性之相關性。物性分析中以XRD、Raman、UV-Vis、SEM、AFM、XPS、FTIR等儀器進行檢測，分析光觸媒薄膜其結晶性、穿透度、表面形貌結構、以及表面官能基對光催化活性及光誘導親水性之影響，並藉由物性分析探討其親水機制。光催化活性中則分為液相及氣相光催化進行測試，其中液相係為於紫外光激發下測試其對亞甲基藍的降解效率，而氣相則為於紫外光激發下探討其對於氮氧化物氧化的效率。另外，將光觸媒薄膜鍍上油性汙染物確認其自我潔淨能力以及放置不同黑暗環境下其親水性之維持時間。
實驗結果顯示當二氧化鈦溶膠濃度為10 wt%以及鍛燒溫度為300℃為最佳之製備參數，隨後摻入適量(0.5 wt%)的銀改質二氧化鈦能有效提升光催化活性。由物性分析結果可知，適當的銀離子能夠有效地抑制電子與電洞對再結合，使得光催化活性提升。在光誘導親水性實驗中得知銀含量於1.0 wt%時，光觸媒薄膜在不需紫外光誘導下即有親水特性，且持續的照射紫外光，可維持其親水狀態。由FTIR物性分析可知，適量的銀摻入能有助於光觸媒試片吸附水之能力，於光觸媒表面形成水膜，使得表面達親水性。在紫外光誘導下，光觸媒薄膜表面產生更多OH基，進而吸附更多水分子，使其快速地達成超親水狀態。自我潔淨實驗結果顯示，銀改質二氧化鈦薄膜，因表面水膜之效應能有效抑制油性汙染物附著，且再經由紫外光照射及水洗步驟後，能有效移除油性物染物。在高濕度環境下，銀改質二氧化鈦薄膜能維
持其親水狀態，主要係因為薄膜表面之水膜維持性最佳，能抑制空氣中之氧氣或水氣取代表面之OH基，使光觸媒表面能長期維持親水狀，而提升其實用性。

In the study, the silver-modified titania film was easily prepared by dip-coating method with using a silver nitrate-containing TiO2 sol. The Ag-TiO2 film, which was calcined at 300 oC with using 10 wt% TiO2 sol containing 0.5-1.0 wt% of silver nitrate, exhibited highly photocatalytic activity for the degradation of gaseous NOx and decolorization of aqueous methylene blue, and photo-induced hydrophilicity under UV illumination. The effects of concentration of TiO2 sol, calcination temperature, concentration of silver nitrate on photoactivity, photo-induced hydrophilicity, and physical property were investigated in detail for the clarification of photocatalytic activity and hydrophilic mechanism.
Physical properties of the film were determined by X-ray diffractometer (XRD), Raman spectroscopy, ultraviolet-visible absorption spectrometry (UV-Vis)、scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometry (FTIR), respectively. These results indicated the differences among prepared films in the crystal structure, surface morphology, functional group, and light absorption. In addition, the oil pollutant was applied to investigate self-cleaning property and the sustainability of hydrophilicity in different dark conditions.
The results indicated the titania film with 1.0 wt% of silver has best wettability without UV illumination and also can reduce the adhesion between oil pollutant and film. The oil on the surface was further degraded and removed by UV illumination and washing with water. Silver ions herein retarded the electrons-hole recombination rate and enhance the adsorption of water molecule on the titania surface, resulting in the excellent wettability. The mechanism of photo-induced hydrophilicity is that plenty OH groups is formed under illumination and they can adsorb water molecules to form water film. The silver-modified titania film already had the water film without UV illumination due to its surface functional groups, so the adhesion of oil pollutant to film was restrained. Silver-modification can keep the titania film hydrophlic for a long time in a humid dark environment. The OH groups on silver-modified titania film had more resistance to oxygen and water molecules in air, resulting in the increase in its practicability.

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