固溶體型二氧化鈦光觸媒的製備、特性分析和光催化效能提升

在過去的研究中有透過摻雜過渡金屬元素到二氧化鈦(TiO_2)光觸媒粉體結構中，藉此改變TiO_2光觸媒粉體的性質來提升其光催化能力。本研究延續本實驗室過去研發的磷矽二氧化鈦光觸媒奈米粉體(〖(P,Si)-TiO〗_2)，透過過渡金屬元素錳(Mn)的摻雜，形成具更高光催化能力的〖(P,Si,Mn)-TiO〗_2光觸媒粉體，結合本實驗室開發的光觸媒厚膜製程，製備出具更高光催化效能的二氧化鈦光觸媒厚膜。本研究以溶膠-凝膠法製備摻雜了P、Si和Mn的固溶體型二氧化鈦光觸媒粉體，並結合溶膠-凝膠法、旋轉塗布法和棒塗法將TiO_2光觸媒粉體配製成漿料，塗布到玻璃基材上，經過適當溫度的熱處理形成TiO_2光觸媒厚膜。會藉由X光繞射分析儀(X-ray diffractmeter, XRD)、紫外光-可見光光譜儀(UV-Visible spectrophotometer, UV-Vis)、比表面積分析儀(Surface area and porosimetric analyzer)、掃描式電子顯微鏡(Scanning electron microscope, SEM)、熱重量分析與熱示差同步熱分析儀(Simultaneous thermogravimetric and differential scanning calorimetric analyzer, TG-DSC)等儀器與光催化實驗、百格測試、再使用測試等分析方式來探討〖(P,Si,Mn)-TiO〗_2光觸媒粉體和厚膜的性質。結果顯示，適量Mn摻雜的TiO_2光觸媒在光催化效能上有顯著的提升，其中光催化效果最佳的是總摻雜量為3%，P、Si和Mn摻雜比例為1比1比4，熱處理溫度800℃的TiO_2光觸媒。在粉體的部分，相對於未摻雜Mn的TiO_2光觸媒粉體其光催化效能提升2.32倍;在厚膜的部分，相對於TiO_2薄膜光催化效能提升4.43倍，而相對於未摻雜Mn的TiO_2光觸媒厚膜光催化效能提升2.32倍。上述的結果證實了Mn摻雜有益於改善〖(P,Si)-TiO〗_2光觸媒的光催化能力。然後在TiO_2光觸媒厚膜附著性測試上也有不錯的結果，百格測試的結果為4B。而在再使用測試中，TiO_2光觸媒厚膜的光催化能力亦未有顯著的下降。上述的實驗結果證明了以〖(P,Si,Mn)-TiO〗_2光觸媒粉體為原料，透過本實驗室開發的光觸媒厚膜製程所製備出的〖(P,Si,Mn)-TiO〗_2光觸媒厚膜在保有一定的附著性和穩定性下，具有優異的光催化效能。

關鍵字

固溶體型二氧化鈦光觸媒； Mn摻雜；溶膠-凝膠法；光催化

並列摘要

To change the properties of titanium dioxide(TiO_2) photocatalyst powder and improve its photocatalytic ability, the structure of TiO_2 photocatalyst powder was doped by doping transition metal elements. This research continues the 〖(P,Si)-TiO〗_2 photocatalyst nanopowder developed by our laboratory in the past. Doping transition metal element manganese (Mn) to get the 〖(P,Si,Mn)-TiO〗_2 photocatalyst powder with higher photocatalytic ability. Combined with the photocatalyst thick film process developed by our laboratory, a TiO_2 photocatalyst thick film with higher photocatalytic performance is prepared. In this study, use the sol-gel method to prepare the solid solution type titanium dioxide photocatalyst powder doped with P, Si and Mn. And the TiO_2 photocatalyst thick film was prepared by combining the sol-gel method, spin coating method, bar coating method and heat treatment at appropriate temperature. We will use some different way to analyze and investigate the properties of 〖(P,Si,Mn)-TiO〗_2 photocatalyst powder and thick film, like X-ray diffractmeter(XRD) , UV-Visible spectrophotometer(UV-Vis), Surface area and porosimetric analyzer, Scanning electron microscope(SEM), Simultaneous thermogravimetric and differential scanning calorimetric analyzer(TG-DSC), photocatalysic ability experiment, adhesion test, recycle-using test, etc. The results show that the TiO_2 photocatalyst doped with an appropriate amount of Mn has a significant improvement in photocatalytic performance. The best one is with heat treatment temperature at 800℃, the total doping is 3% (doping ratio of P, Si and Mn is 1: 1: 4). In the part of the powder, the photocatalytic performance of the TiO_2 photocatalyst powder is increased by 2.32 times compared with the undoped Mn; in the part of the thick film, compared with the photocatalytic performance of the TiO_2 thin film is increased by 4.43 times, and compared with the thick film that undoped Mn, the photocatalytic efficiency is increase 2.32 times. Theese results confirm that Mn doping is beneficial to improve the photocatalytic ability of 〖(P,Si)-TiO〗_2 photocatalyst. Besides these, there are good results in the adhesion test of the TiO_2 photocatalyst thick film, and the result of the adhesion test is 4B. In the recycle-using test, the photocatalytic ability of the TiO_2 photocatalyst thick film did not decrease significantly. All of the experimental results prove that 〖(P,Si,Mn)-TiO〗_2 has the good photocatalytic performance when it keep the nice adhesion and stability.