氧化鈦/銀表面微型結構之光觸媒活性與殺菌特性之研究

Characteristic on the Photocatalytic Activity and Sterilization of a Titanium Oxide / Silver Surface Micro-structures

黃鉦皓(Cheng-Hao Huang)

指導教授 ： 劉代山

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2015年)

https://doi.org/10.6827/NFU.2015.00011

摘要

本研究利用電漿增強化學氣相沉積系統(Plasma Enhance Chemical Vapor Deposition，PECVD )沉積非晶氧化鈦薄膜(厚度約200 nm)，並且使用高溫爐於溫度500℃下進行後續氧氣熱處理來提升氧化鈦薄膜結構使其形成具備銳鈦礦(Anatase)結構之多晶氧化鈦薄膜。接著，再利用金屬蒸鍍系統沉積銀金屬薄膜(∼10 nm)後，並利用快速熱退火爐經由不同環境、熱處理溫度來製備氧化鈦/銀金屬薄膜表面微型結構，分別與單層銀金屬薄膜共同探討於不同熱退火環境與溫度對其薄膜之影響，並使用原子力顯微鏡(AFM)、X光射線繞射儀(XRD)、場發射掃描式電子顯微鏡(FE-SEM)、X光光電子能譜儀(XPS)等儀器進行量測及分析薄膜材料特性。最後，將氧化鈦/銀雙層結構薄膜進行紫外光(5 mW/cm2)及可見光(10 mW/cm2)光觸媒降解亞甲基藍液以及大腸桿菌殺菌實驗，並以多晶氧化鈦薄膜作為本研究對照組，比較其光觸媒降解特性及殺菌特性。
本研究中，首先從銀金屬薄膜進行分析，FE-SEM結果顯示銀金屬薄膜經高溫熱處理後其表面粒子會團聚形成顆粒狀的奈米銀粒子，而奈米銀粒子有其特殊的局部性表面電漿共振效應，其共振波的頻率會隨粒子大小而有所變化，而從光觸媒降解亞甲基藍溶液實驗中可以發現銀金屬薄膜經由500℃氮氣環境熱退火處理在紫外光及可見光照射下對於亞甲基藍溶液之光降解反應速率常數k值為0.00369 min-1與0.0172 min-1，皆優於銀金屬薄膜在其他環境與溫度之光降解反應速率常數。接著進行氧化鈦/銀雙層結構薄膜研究，結果顯示從FE-SEM可以發現到經由熱處理後之表面銀粒子會團聚以及擴散至下層的多晶氧化鈦薄膜中，且從XPS的Ti 2p軌域中可以發現經由熱退火處理後，Ti 2p3/2軌域束縛能能量有紅移現象產生，表示多晶氧化鈦薄膜因為銀粒子的添加使得有較多的Ti3+存在，然而Ti3+存在將會有利於減緩照光後產生的電子-電洞對復合率，因此，從光觸媒降解亞甲基藍溶液實驗中可以發現，氧化鈦/銀雙層結構薄膜經過500℃氮氣環境熱退火處理後在紫外光及可見光照射下對於亞甲基藍溶液的光降解反應速率常數k值為0.0154 min-1及0.0360 min-1，優異於其他氧化鈦/銀雙層結構薄膜以及多晶氧化鈦薄膜。最後將進行光觸媒大腸桿菌殺菌實驗，研究結果顯示，多晶氧化鈦對大腸桿菌殺菌效果有限，於紫外光及可見光照射下其殺菌率分別為39.8 %與23.9 %，而單層銀金屬經由紫外光與可見光照射下之殺菌率分別為43.6 %以及59.1 %，因奈米銀金屬本身即具有抗菌特性，因此對大腸桿菌有較佳之殺菌效果。本研究使用氧化鈦/銀金屬結構進行改善，其中以氧化鈦/銀經過500℃氮氣環境熱處理後結構對於大腸桿菌殺菌效果最佳，在紫外光與可見光照射下其殺菌率皆可高達100 %，因其具有較大的光觸媒反應面積以及較高的光量子轉換效率，綜合以上結果證實具有氧化鈦/銀金屬結構確實能有效提升氧化鈦薄膜的光觸媒特性與抗菌特性。

關鍵字

電漿增強化學氣相沉積系統 ； 微型結構 ； 氧化鈦薄膜 ； 光降解反應 ； 殺菌性能

並列摘要

In this study, plasma enhanced chemical vapor deposition system (Plasma Enhance Chemical Vapor Deposition, PECVD) deposition of amorphous titanium oxide film (thickness of about 200 nm), and the use of high-temperature furnace for subsequent heat treatment at 500℃ in oxygen ambient. For enhance titanium oxide film with the formation of anatase crystal structure. Then, using a metal deposition system to deposit the silver metal film (~ 10 nm), and using rapid thermal annealing furnace via the different environment, and the different heat treatment temperature to prepare a titanium oxide / silver metal film surface micro-structure. Respectively, investigate the effect with single silver metal film and titanium oxide / silver metal film on the different environment and the different thermal annealing temperature. Using an atomic force microscope (AFM), X-ray diffraction analyzer (XRD), field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectrometer (XPS) and other instruments to measure and analyze the film material properties. Finally, the titanium oxide / silver double-layer structure films under ultraviolet (5 mW/cm2) and visible light (10 mW/cm2) photocatalytic degradation of methylene blue solution as well as E. coli sterilization experiments, and poly titanium oxide film as the control group in this study to compare the photocatalytic degradation characteristics and bactericidal properties.
In this study, the first to analyze from a silver metal film. FE-SEM results show that silver metal film after high temperature heat treatment on its surface particles may agglomerate granular form nano silver particles, The silver nanoparticles have special localized surface plasma resonance effect. The frequency resonant wave will vary with particle size. From the photocatalytic degradation of methylene blue solution experiments can be found in silver metal film at 500℃ in nitrogen ambient annealing process under UV and visible light of the degradation reaction rate constant k is 0.00369 min-1 and 0.0172 min-1. It is better than the others silver metal film. Next is investigating the titanium oxide / silver thin films layer structure. The results showed that from FE-SEM can be found on surface of the silver particles after the heat treatment. It will be agglomerating and diffusing to the lower poly titanium oxide thin films. From the Ti 2p XPS results can be found the binding energy of Ti 2p3/2 orbital have red shift phenomenon. Showing a poly titanium oxide film because adding the silver particles and makes it have more Ti3+ exist. However, the presence of Ti3+ will help slower recombination rate of the electron - hole pair after light irradiation. Therefore, from the photocatalytic degradation of methylene blue solution experiments. It can be found, titanium oxide / silver double-layer structure after 500℃ nitrogen ambient thermal annealed. Under ultraviolet light and visible light irradiation, for the degradation of methylene blue reaction rate constant k value is 0.0154 min-1 and 0.0360 min-1. Superior to other titanium oxide / silver double-layer structure and poly titanium oxide thin films. Finally, the experiment will be photocatalyst sterilization of E.coli. The results show that the poly titanium oxide sterilization limited effect on E. coli. Under UV light and visible light irradiation, that in the bactericidal rate was 39.8% and 23.9%, respectively. The sterilization rates of single silver metal film is 43.6% and 59.1% by UV and visible light irradiation, respectively. Silver nanoparticles itself has antibacterial properties, so the sterilization of E. coli have better results.In this study, we make improvement by using titanium oxide / silver metal structure. Among them, titanium oxide / silver film after heat treatment at 500℃ in nitrogen ambient, it have the best sterilization for E. coli. Under UV and visible light irradiation, its sterilization rate as high as 100%. Because of its larger reaction area and higher photon conversion efficiency. Based on the above results, we confirm that with a titanium oxide / silver structures really can effectively enhance the photocatalytic properties and antibacterial properties.

並列關鍵字

PECVD ； micro-structure ； titanium oxide ； degradation reaction ； sterilization properties

參考文獻

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