本研究以溶膠-凝膠法製備出TiO2粉體與薄膜，其中主要完成工作有三：1. 製備高熱穩定且在可見光照射下具高光催化效果的磷-鋅共摻合型TiO2奈米粉體；2. 製備與分析高熱穩定性與高光催化效果的TiO2薄膜；3. 製備與分析P-N接面TiO2薄膜在光電轉換元件應用上的可行性。 第一部份實驗中，主要以溶膠-凝膠法(sol-gel method)來製備P/Zn-TiO2奈米粉體。過程中有系統的探討摻合物(dopants)的比例對其熱穩定性、能隙大小及光催化效果的影響。[H3PO4]/[Zn(NO3)2]≧2時，不僅能夠維持銳鈦礦相態的TiO2至800oC外還能夠在光催化活性的表現上有著優異的表現。P/Zn-TiO2粉體在紫外光照射30分鐘後能夠達到96mol%以上的亞甲基藍降解，而在可見光照射60分鐘後也可以達到80mol%以上的亞甲基藍降解，以上之結果皆比市售TiO2粉體P25有著更好的表現。 第二部份實驗中則利用溶膠-凝膠法及旋轉塗佈技術製備具有與基材有高鍵結力與高熱穩定性的二氧化鈦薄膜並探討其粗糙度、厚度、結晶相態、紫外-可見光吸收度及光催化效果。結果發現以800oC煆燒後的TiO2薄膜因為其擁有最大的銳鈦礦相態晶粒尺寸與孔洞且能吸收較多紫外光，因此有最佳的光催化活性表現。所製備出之TiO2薄膜經行重複的光催化活性實驗以及藉由超音波機震盪後再次觀察其光催化活性，其結果顯示煆燒後的TiO2薄膜皆可保有相似的光催化能力。因此說明此製程所製備出之TiO2薄膜與基材有著緊密的結合性，可以進行重複的光催化反應，大大增加此TiO2薄膜的應用範圍。 最後，在第三部份光電轉化元件製備上，所添加的P5+成功將TiO2薄膜轉變為P型半導體材料並成功製備出凝膠衍生的P型TiO2薄膜，進而披附於N型TiO2薄膜上以製備出含P-N接面的TiO2薄膜。利用SEM觀察TiO2薄膜截面中，N型、P型及P-N接面之厚度分別為50、50及100nm。此製備出之N型、P型及P-N接面在可見光範圍下皆可以達到80%以上之穿透率值。最後利用此含P-N接面的TiO2薄膜與對電極加以組裝後形成一光電轉化元件後，不僅發現此P-N接面擁有開關效應外，含P-N接面的TiO2薄膜比N型TiO2薄膜更能提升其光電轉化效率，提升約363%，而將此含P-N接面的TiO2薄膜應用於目前染料敏化電池元件中時更可提高其光電轉化效率21.7%。 Abstract： TiO2 photocatalyst powder and films were synthesized using sol-gel method. Three major accomplishments were achieved: 1. 5 mol% P/Zn-TiO2 nanoparticles were synthesized using a sol–gel method. The results indicated that by doping both zinc and phosphorus elements into Ti–O framework, the resultant TiO2 can maintain anatase monophase at temperatures as high as 800 ◦C. The P/Zn–TiO2 nanoparticles prepared using [H3PO4]/[Zn(NO3)2]≥2 at 600–800 ◦C can decompose ≥96 mol% of the MB after 30 min of UV irradiation and can decompose ≥80 mol% of the MB after 60 min of white light irradiation, which are much better than those of the P25 particles. 2. The gel-derived TiO2 thin films were prepared and strongly adhered on fused-silica substrates using a spin-coating technique. Effects of calcination temperature on crystal structure, grain size, surface texture, and photocatalytic activity of the TiO2 films were investigated. The photocatalytic activity of the TiO2 thin film is characterized using a characteristic time constant (τ) for the photodecomposition of the methylene blue (MB) in water. The TiO2 films prepared at 800 oC have the best photocatalytic ability. The TiO2 film can be reused after being ultrasonically cleaned and washed with large amount of water, without detectable reduction in its photocatalytic ability. This implies that the prepared TiO2 films were strongly attached on the substrate surface and can be used repeatly. 3. The gel-derived transparent P-type TiO2 thin films was successfully formed by adding the P5+ into the TiO2 thin film. By coating P-type TiO2 films on the N-type TiO2 thin film the TiO2 thin films with P-N junction were prepared. The N-type TiO2, P-type TiO2 and the TiO2 with P-N junction have their film thicknesses of 50, 50 and 100nm respectively. The transmittance on the visible light range is greater than 80% of these three type TiO2 thin films. Finally, the TiO2 with P-N junction was incorporated with the counter electrode to form a photovoltaic device. The TiO2 with P-N junction not only revealed the rectifying effect, but also possessed photovoltaic efficiency than N-type TiO2 thin films, which improved its efficiency about 363%. The use of the TiO2 thin film with P-N junction in DSSC device could improve the photovoltaic efficiency about 21.7%.
