本研究利用溶膠凝膠法(sol-gel)，以MWCNTs為載體，透過有機前驅物鈦酸四乙酯(TEOT)，製備MWCNTs/TiO2奈米光複合觸媒，光催化降解水楊酸之影響。研究係於批次式光催化反應器中進行，測試不同的製備條件如MWCNTs：TiO2之觸媒配比、鍛燒溫度及不同光源對水楊酸光催化降解能力。透過FT-IR圖譜可得知，改質後之MWCNTs表面可增加含氧官能基，而FE-SEM、TEM影像顯示，MWCNTs分散性良好，提高碳管純度，以及表面的破壞所形成缺陷位址有助於TiO2合成。 研究結果顯示，碳管添加量為5 wt%之MWCNTs/TiO2複合材料，於UV光下光催化降解水楊酸效果最佳，可能因碳管吸附之濃縮作用，以及光催化時有助於預防TiO2電子-電洞對再結合，透過協同作用增加TiO2光催化能力，但添加過多的奈米碳管時，會因碳管吸收光源，導致溶液中的MWCNTs/TiO2複合光觸媒之催化能力下降。鍛燒溫度方面，隨著溫度越高，TiO2顆粒燒結團聚現象嚴重，會導致光催化能力下降。透過Langmuir -Hinshelwood反應動力模式進行擬合，MWCNTs/TiO2複合材料光觸媒在UV光下進行光催化，其光源波長較短，觸媒上的電子較易被激發使得催化能力較強，反應碰撞較為激烈，較符合擬二階反應動力模式。 In this study, MWCNTs/TiO2 composites were prepared using multi- walled carbon nanotubes as a starting material, and titanium ethoxide as the precursor of TiO2. This process involves the hydrolysis and polycondensation of a precursor and subsequent formation of the gel, which results in a crystalline network structure after heat treatment. The influences of MWCNTs: TiO2 ratio and calcination temperature on the physical as well as chemical characteristic and photocatalytic ability, which was examined by conduction photocatalytic degradation of of salicylic acid by both UV and visible lights. Comparing to the TiO2 catalysts systhesized in this work, TiO2 /MWCNTs composites has better photocatalytic activity. This suggests that the MWCNTs may hinder the recombination of electron and electron holes. However, when MWCNTs: TiO2 is higher than 5%, the addition of MWCNTs reduced the photocatalytic ability because that the MWCNTs are black and would block or adsorb the incident light.
