以氣相法製備氮摻雜之可見光觸媒/中孔洞分子篩複合材料同時處理VOCs及NOx之研究

Abstract

由於氮摻雜二氧化鈦(N-TiO2)光觸媒在可見光照射下有光催化之效果，而中孔洞分子篩(mesoporous silica particles，MSP)材料可作為吸附劑使用，因此，本研究以機械混合方式製備N-TiO2/MSP複合材料，結合兩者之特性可同時去除空氣中之VOCs與NOx等污染物，並改善傳統吸附劑之除污能力，達到同時吸附與光催化之目標。實驗所製備之複合材料，經由XRD、DRS UV-Vis、SEM、TEM等儀器進行特性分析。而實驗的進行是利用可見光光源，分別以Acetone與NO做為VOCs與NOx之來源，並以連續式反應器測試Acetone與NO之濃度變化情形。實驗結果發現，製備N-TiO2時之TTIP/H2O前驅物體積流率比為4時，N-TiO2/MSP複合材料有較佳的Acetone與NO光催化效能；且其相較於N-TiO2/ZSM-5與ST-01/MSP複合材料，亦有較佳之光催化效能；在改變不同重量比之N-TiO2/MSP複合材料時，發現N-TiO2(60)/MSP之重量比有最佳Acetone與NO之除污效能。本實驗亦改變不同停留時間、NO濃度等實驗條件，以瞭解各參數之影響。對於N-TiO2(60)/MSP複合材料探討個別處理Acetone與NO和同時處理Acetone與NO之研究，並改變不同Acetone之濃度，探討其對NO去除之影響，並同時探討NO2選擇率與硝酸形成機率。另一方面，對於N-TiO2光觸媒樣品而言，發現兩種污染物共存時之處理效能會低於個別存在時之情況，為一競爭去除關係；而當N-TiO2與MSP結合時，兩者互為協同去除關係，即兩種污染物共存時之處理效能會高於個別存在時之情況。

The purpose of this study is to understand continuous and simultaneous removals of acetone solvent vapors and NO under visible light at room temperature over N-TiO2/MSP composite. It can achieve the goal that N-TiO2/MSP composite can adsorb the pollutants on the surface and then photocatalytically decompose the pollutants subsequently. The catalyst are characterized by XRD、UV-vis、SEM、TEM and FTIR analysis. The simultaneous abatement of acetone and NO pollutants was carried out using a continuous flow reactor system under fluorescent lamps. The results show that the best N-TiO2 can be abtained at TTIP/H2O volumetric flow rate ratio of 4 is more effective than other ratios. For simultaneous removal of acetone and NO, the 60/40 mass ratio of N-TiO2/MSP composite shows the highest acetone and NO removals. For pure N-TiO2 photocatalyst, the coexistence of acetone and NO shows the competition effect. On the other hand, for the test of N-TiO2/MSP composite, the coexistence of acetone and NO shows coordinated dependent or competition effect.