退火製程對於二氧化鈦薄膜光催化降解亞甲藍之研究

Effects of annealing processes on photocatalytic degradation of Methylene Blue of TiO2 films

李冠源(Li Guan-Yuan)

指導教授 ： 林鉉凱 ； 苗志銘

國立屏東科技大學/工學院/材料工程研究所/碩士(2019年)

https://doi.org/10.6346/NPUST201900146

摘要

本實驗使用高真空濺鍍系統，於室溫下沉積不同厚度二氧化鈦薄膜，並比較快速退火爐與雷射表面處理後之結晶結構、光性、表面形貌，最後使用UV燈降解亞甲藍。結果顯示未退火薄膜隨著薄膜厚度增加降解效率越好，在150 nm時因有最大RMS 2.579 nm，而有較大降解效率84.6%。三種厚度50、100、150 nm經過RTA退火，均顯示在100 nm下有最佳的降解效率，也是因為有著最大的RMS，可增加表面積促進光催化效率。在大氣環境下可看出退火溫度從200oC增加到600oC，降解效率從85%提升至86.3%，氧氣環境也是從86.7%提升至89.3%，從晶體分析中發現在400oC就開始出現銳鈦礦，並且降解效率也明顯提升。接著雷射處理中發現在2.35 W-150 mm/s有最佳的降解84.9%。最後可以發現在厚度100 nm下，使用RTA氧氣退火600oC效果明顯比RTA大氣退火600oC與雷射處理要好，因為其晶體結構為銳鈦礦，能隙3.42 eV，且有最大的RMS值3.214 nm。

關鍵字

二氧化鈦 ； 光觸媒 ； 快速退火爐 ； 雷射表面處理 ； 亞甲藍

並列摘要

Titanium dioxide films with thicknesses were deposited by high vacuum sputter system at room temperature. The crystal structure, band gap and surface morphology were compared between RTA and laser surface treatment. Methylene blue was degraded by UV lamp. The results showed that the as-deposited film had the best degradation efficiency, following the increase of film thickness. The 150 nm thickness sample with a maximum RMS of 2.579 nm had the best degradation efficiency 84.6%. The samples (50, 100 and 150 nm) were annealed by RTA, and all results showed the best degradation efficiency at 100 nm due to the largest RMS. The surface area increased and the photocatalytic efficiency would be enhanced. The annealing temperature increased from 200oC to 600oC, and then the degradation efficiency increased from 85% to 86.3% in atmospheric environment. In addition it also increased from 86.7% to 89.3% in oxygen environment. According to XRD result, phase was transferred to anatase at 400oC, and the degradation efficiency was also significantly improved. The degradation efficiency is up to 84.9% after laser surface treatment (2.35 W-150 mm/s). Finally, the samples fixed at 100 nm, the degradation efficiency of RTA in oxygen condition were better than that of RTA in atmospheric condition or laser treatment. Because of anatase phase, the higher band gap (3.42 eV), and the maximum RMS (3.214 nm), the better degradation efficiency would be obtained.

並列關鍵字

Titanium dioxide ； Photocatalyst ； RTA ； Laser surface treatment ； Methylene blue

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