玻璃管上ZnO光觸媒膜的製備與特性分析

Preparation and characterization of ZnO photocatalytic films on glass tubes

裴怡靜(I-Ching Pei)

指導教授 ： 余宣賦

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2018年)

https://doi.org/10.6846/TKU.2018.00136

摘要

本研究以化學浴沉降技術(chemical bath deposition；CBD)將高光催化效能之ZnO膜均勻且穩固的被覆在經過錳酸鉀活化後的玻璃管上。製得之ZnO膜會進行X-光繞射儀、掃描式電子顯微鏡和紫外光-可見光光譜儀等測試來了解其特性。研究中探討活化過程及煆燒程序的必要性，並調整CBD溶液中乙醇胺及氨水體積比，來瞭解其對所製得ZnO膜微結構的影響。結果顯示，玻璃管經過活化後CBD衍生之ZnO膜被覆均勻，500 oC煆燒的過程也有效的增加ZnO膜與玻璃管之間的結合性。CBD溶液中，乙醇胺及氨水體積比會影響所形成ZnO膜的結晶程度、ZnO柱的尺寸及光催化能力。在適當乙醇胺及氨水體積比下可得到均勻且穩固的ZnO膜。ZnO膜的光催化能力以其光降解水中亞甲基藍所對應的特徵時間常數(τ)來表示，其中τ值越小代表光催化效能越好。光催化分析中，以乙醇胺及氨水體積比為12:2所製得的ZnO膜光催化效果最佳，光催化反應2小時可分解99%的亞甲基藍，其τ值為0.61 h。製得之ZnO膜經過連續10次的光催化測試發現ZnO膜仍具有相同的光催化效能，且比較光催化前後ZnO膜表面微結構並無偵測到明顯差異。光觸媒面積(NS；N:管數，S:單一管之ZnO膜面積)及光照強度(I)會影響光催化效能，經實驗分析得知光觸媒面積與光催化效果成正比關係，而光照強度與光催化效果成指數關係。將不同實驗條件下量測所得特徵時間常數值進行實驗數據的曲線擬合分析，得到其關係式為：τ=[(2.88×〖10〗^(-2) N+8.92×〖10〗^(-2))I^0.23 ]^(-1)。此關係式可充分地描述玻璃管上ZnO膜降解不同濃度的亞甲基藍之行為模式。

關鍵字

氧化鋅 ； 光觸媒膜 ； 光催化能力 ； 動力學分析

並列摘要

ZnO films with high photocatalytic activity were uniformly and firmly deposited on the KMnO4(aq) activated glass tubes by chemical bath deposition method (CBD). The obtained ZnO films were characterized using X-ray diffractometer (XRD), scanning electron microscope (SEM), and ultraviolet-visible spectrophotometer (UV-Vis). Photoacatalytic activity of the obtained ZnO film was measured by photocatalytically degrading methylene blue (MB) in water, under illumination of 365-nm UV light. Effects of the glass activation process, heating process and volume ratios of ethanolamine to ammonia in CBD solution on ZnO film microstructure were investigated and discussed. By using proper volume ratios of ethanolamine/ammonia, the CBD-derived ZnO films calcined at 500 oC had strong adhesion to the surface of glass tubes. The photocatalytic ability of ZnO films were represented using a characteristic time constant (τ) for the photocatalytic degradation of methylene blue in water. The smaller τ stands for higher photocatalytic ability of the film. The ZnO film, prepared using volume ratio ethanolamine：ammonia = 12：2 had superior photocatalytic ability; after 2 hour, almost 99% degradation of methylene blue were achieved, and its τ value was 0.61 h. After repeating 10 times of the photocatalytic test, the ZnO film still possessed the same photocatalytic activity and the microstructure of the film didn’t showed any significant differences. Kinetic analysis indicated that the value of τ was affected by the photocatalyst areas (NS; N: tube number, S: single tube ZnO film area) and light intensity (I). The equation, τ=[(2.88×〖10〗^(-2) N+8.92×〖10〗^(-2))I^0.23 ]^(-1), can well describe the photocatalytic performance of the prepared ZnO film at different concentrations of methylene blue and operation conditions.

並列關鍵字

ZnO ； photocatalytic films ； photocatalysis ； kinetic analysis

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