目前如何運用二氧化鈦觸媒光降解技術於大氣污染防治以及在環境上去除有機汙染物質上一直廣受世界各國注意。二氧化鈦光觸媒在經過處理並與其它原子結合成新的化合物,可以改變原本二氧化鈦本身被激發的吸收波長,使得二氧化鈦光觸媒能夠在可見光下就能夠有良好的作用。但是無論如何改變二氧化鈦觸媒的光吸收波長,二氧化鈦觸媒本身還是必須被光激發才能發揮效用,故在工程使用上較容易受到光源使用不易之限制,國內外目前鮮少有相關研究指出TiO2可直接藉由通入電流後產生電子-電洞分離特性之研究。如果可以製備一個導電型二氧化鈦就能以電來驅動光觸媒,則前述之缺點就得以改善。我們利用溶膠凝膠法(sol-gel)製作Bi/TiO2粉體,製備出鉍(Bi)含量1%~90%的Bi/TiO2導電觸媒粉體並成功的將提高導電性,實驗結果數據顯示二氧化鈦結合鉍(Bi)能提高導電度98%。而經由以Bi/TiO2導電觸媒粉體降解甲基藍結果得知,較佳的配比為添加1% Bi的Bi/TiO2導電觸媒。而另一降解效果較為理想的配比為添加90%的Bi,但Bi為貴金屬因此添加過多的Bi會無法符合經濟效益。
How to use the photo-catalytic property of titanium dioxide (TiO2) in the air pollution control, for the removal of organic pollutants in environmental has caused much attentions internationally. The TiO2 photocatalyst can change its original absorption of excitation energy in the combination with other atoms into new elements; can make the TiO2 photocatalyst in visible light to be able to have a good efficiency. Until now any TiO2 catalyst must be photo excited by light has become a limitation in engineering applications. Researchers rarely reported that TiO2 can be excited electronically. If we can prepare a electro-conductive TiO2, then we can drive TiO2 photocatalyst by electricity. In this study we have used the sol-gel process to synthesis Bi/TiO2 powder, with the doping of the bismuth (Bi) 1 to 90% successfully. And experimental data result show the combination of Bi into TiO2 can increase conductivity to 98%. Use the Bi/TiO2 conductive catalyst powder to removal methyl bule dye from water solution, data shows that the best doping ratio is 1%, and other one better ratio is 90%, but Bi is very expensive so add less Bi would be more economic for future application.