本實驗利用溶膠-凝膠法和旋轉塗佈技術來合成TiO2和P/Si-TiO2光觸媒薄膜。實驗程序中，固定摻雜物(磷、矽)的總莫爾添加量以探討磷、矽的莫爾比的改變(R = [P] / ([P]+[Si]))和煆燒溫度對P/Si-TiO2薄膜結晶相態、晶粒尺寸、薄膜厚度、薄膜表面形態、光穿透率、能隙以及光降解特性的影響，並與未摻雜的TiO2薄膜作性質的比較。實驗的結果顯示：同時摻入磷、矽元素於TiO2結構中的P/Si-TiO2（0.33≦R≦0.67）薄膜可與基材有緊密的結合性並且所製得的銳鈦礦TiO2具有優越的熱穩定性，銳鈦礦結構可維持至900℃。製得薄膜的光催化能力以其對亞甲基藍光降解反應所對應的特性時間常數（τ）予以量化，τ值愈小表示二氧化鈦薄膜具愈高的光催化能力。整體而言，經過800℃煆燒處理後的P/Si-TiO2(R=0.5)薄膜利用365-nm紫外光照射12小時後具有最佳的光催化能力，其可分解90%的亞甲基藍並且特性時間常數為5.7小時。 The P/Si-TiO2 thin films, with a molar ratio [P+Si]/[P/Si-TiO2]=0.03, were synthesized by the sol–gel method and spin-coating technique. Effects of relative ratios of dopants (i.e., R≡[P]/([ P+Si]) and calcination temperatures on phase transformation, grain growth, film thickness, surface morphology, light transmittance, energy gap and photocatalytic activity of the gel-derived P/Si-TiO2 thin films were examined and their results were compared with those of the undoped TiO2 thin films. By simultaneously doping Si and P elements into the Ti-O framework, the P/Si-TiO2 (i.e., 0.33≤ R ≤0.67) thin films calcined at ≦900℃ adhered strongly to the surface of fused-silica substrate and were composed of anatase-TiO2 only. The photocatalytic activities of the thin films were measured and represented using a characteristic time constant (τ) for the MB degradation. The small τ stands for high photocatalytic ability. The P/Si-TiO2 thin film prepared at R = 0.5 and 800℃ gave the best photocatalytic activity; this thin film decomposed about 90 mole% of MB in the water (the corresponding τ = 5.7 h), after 365-nm UV light irradiation for 12 h.