本研究中首先以溶膠凝膠法製備一系列之二氧化鈰-二氧化鈦材料與含銀之二氧化鈰-二氧化鈦材料。除了藉由X光粉末繞射儀、穿透式電子顯微鏡、紫外-可見光光譜儀、原子力顯微鏡、掃描式電子顯微鏡與X光電子/歐傑電子能譜儀等儀器分析材料之性質之外，再以紫外光與可見光照射條件下，亞甲基藍降解來測試材料之光觸媒活性。其中，二氧化鈰-二氧化鈦重量比為0.05比1為活性效能最高之樣品。藉由添加二氧化鈰後形成鈰-氧-鈦之鍵結改變二氧化鈦的吸收光譜能階，達到較高的光觸媒活性效能。最後探討在抗菌應用方面，二氧化鈰-二氧化鈦材料於照光條件下有抗菌功效，但添加銀之二氧化鈰-二氧化鈦材料可達到在照紫外光條件與無光環境下均有抗菌效能。藉由大腸桿菌(Escherichia coli (OP50), 革蘭氏陰性細菌)與耐甲氧金黃色葡萄球菌 (methicillin-resistant Staphylococcus aureus (USA300), 革蘭氏陽性細菌)來進行二氧化鈰-二氧化鈦系列材料抗菌活性測試。其中，含銀之二氧化鈰-二氧化鈦材料之樣品，在UVA照射30分鐘後與暗條件下，大腸桿菌與MRSA之抗菌效能均可大於99.99%。此材料之抗菌活性效能相較於純二氧化鈦、二氧化鈰-二氧化鈦與純銀之材料相比，不論應用於革蘭氏陽性細菌或是革蘭氏陰性細菌，其抗菌結果均達到最高的效能。;A series of CeO2–TiO2 mixed oxides and anatase TiO2 co‒doped with Ag and CeO2 (Ag/CeO2‒TiO2) were prepared by the peroxo sol-gel method. X-ray diffraction, transmission electron microscopy, UV–vis spectroscopy, atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy were used to investigate the characteristics of the as-prepared materials in order to determine the influence of adding CeO2 to TiO2 on the photocatalytic degradation of methylene blue aqueous solution under both UV and visible light irradiation. It was observed that the highest photocatalytic degradation activities with respect to methylene blue under both UV and visible light irradiation were exhibited for an optimum CeO2–TiO2 weight ratio of 0.05. The high photocatalytic activity was because of changes in the spectral absorption of material, which was attributed to the heterojunction formed by TiO2 and CeO2 networks via Ti–O–Ce bonds after addition of CeO2. However, for antibacterial application, the activity of CeO2–TiO2 mixed oxide was limited to conditions of irradiation; thus, silver was used to enhance antibacterial activity. The antibacterial activities of the samples were tested against two different bacteria: Escherichia coli (OP50), a Gram-negative organism and methicillin-resistant Staphylococcus aureus (USA300), a Gram-positive organism. The antibacterial effectiveness of the Ag/CeO2‒TiO2 coating was > 99.99%, i.e. it was extremely effective against both E. coli (OP50) and S. aureus (USA300) after either 30 min of illumination with UVA radiation or 24-hour of incubation in the dark. The Ag/CeO2‒TiO2 coating was found to be significantly more active than pure TiO2 and TiO2 doped with CeO2 or Ag alone. Therefore, Ag/CeO2‒TiO2 can be used as a coating material for the disinfection of both Gram-positive and Gram-negative bacteria.
