本研究利用自製與市售的二氧化鈦光觸媒對亞甲基藍水容液進行光催化反應，探討不同照射光源、觸媒添加量、濃度物濃度及起始pH值對光催化反應的影響，並以XRD 、 BET及SEM等觸媒鑑定方法確認自製二氧化鈦光觸媒晶相與觸媒粒徑。 從光觸媒之物性測生測試實驗結果得知，自製鼴市售Merck Ti02觸媒會產生明顯且集中的線性雷射光束，表示這兩種觸媒粒徑較小，光催化反應的效果較好，此白實驗獲得驗證，在365nm光源照射照射下，亞甲基藍濃度Ioppm、觸媒添加量0.75g/L，兩者在六小時之脫色率皆超過95% :在觸媒添加量方面，上述兩種觸媒的催化效能隨著添加量的增加而遞增，但在超過0.Sg/L後，其脫色率增加的效果並不顯著;在雖反應物濃度方面，兩者在六小時之脫色率，隨著亞甲基藍濃度的增加而下降，在20ppm、30ppm及40ppm時，本研究室自製的Ti02觸媒其光催化效能優於市售行;在起始pH值方面，市售Merck Ti02觸媒的催化效能為pHIO>oH6>DH3，而自掣的TiO2觸媒的催化效能為pH6>pHlO>pH3，顯示兩種觸媒在非酬生的環境下有較好的脫色效果。 This study we used self-made and commercial TiO2 catalyst to investigate the photocatalytic oxidation of methylene blue(MB) by reaction conditions like the light source, catalyst loading, initial concentration of MB and initial pH. This paper also examined the crystalline phase and diameter of catalysts via the characterization of catalysts of XRD、BET and SEM. For the physical test of photocatalyst, we found both self-made and commercial Merck TiO2 catalyst result an apparently and centrally linear laser beam, may show these catalysts with small diameter and perform better in photocatalytic oxidation. The experimental result indicated these catalysts enables over 95% color removal after 6h of reaction in 10 ppm MB solution under the light source of 365nm with 0.75 g/L of catalyst loading. The efficacies of photocatalytic oxidation of MB increased with catalysts loading, but no significant increase when catalysts loading over 0.5g/L. The color removal after 6h of reaction decreased as initial MB concentration increased. As for initial concentration of MB, self-made TiO2 was superior to Merck at the MB solutions of20 ppm、30 ppm and 40 ppm. For initial pH, it was found that the order of efficiency of Merck was pH10>pH6>pH3, while the efficiency of self-made was pH6>pH10>pH3, which indicated both catalysts are favorable in non-acidic solutions.