製備碳量子點/羫基錫酸鋅光催化薄膜在可見光下去除染料廢水之研究

Application of CQDs/ZnSn(OH)6 Photocatalytic membrane on Dye Wastewater Degradation

鍾文勝(Wen-Sheng Zhong)

指導教授 ： 游勝傑 ； 王雅玢

中原大學/工學院/環境工程學系/碩士(2019年)

https://doi.org/10.6840/cycu201900857

摘要

在人類生活中，染料的使用無所不在，主要是用來各式物品上色，以增添物品色彩與鮮豔度，隨著科技日新月異，調配出許多種類的染料，而也為了因應現代社會的需求，逐漸將染料設計成抗氧化、抗日照、抗分解，這導致染料的穩定性高，不受溫度、光線、化學物質、肥皂、洗潔劑或其他生活條件如汗水、漂白的影響，所以大部分染料污水無法被污水處理系統完全處理。本研究利用光催化與膜分離技術，製成光催化薄膜，用來處理染料廢水，分解成更低汙染、更容易分解的副產物，去除其色度。
本研究光催化劑製備利用水熱法製備碳量子點(Carbon Quantum Dot, CQDs)，以五水合四氯化錫(SnCl4˙5H2O)與乙酸鋅(Zn(CH₃COO)₂)作為錫源與鋅源，成功製備出CQDs/ZHS複合光催化劑，且採取不同合成溫度、不同CQDs摻雜量、不同實驗劑量進行甲基藍染料2500 ADMI降解實驗，為的是找出最佳條件的催化劑，在薄膜製備選用市售疏水性聚偏氟乙烯膜(PVDF)，使用實驗室低溫電漿模組進行膜表面改質，成功由疏水性表面改質成親水性表面，將改質後的膜泡在催化劑水溶液裡震盪，使粉末均勻分散，利用凡德瓦爾力的交互作用力，成功使催化劑附著在薄膜上。實驗以甲基藍染料進行光催化劑最佳條件選擇，光催化薄膜使用自己設計的光催化模組進行實場染料廢水實驗，討論CQDs/ZHS複合光催化劑製成的光催化薄膜去除色度之效果，以及未來改善。
實驗結果顯示，合成溫度160oC的羫基錫酸鋅(ZHS)有著最穩定且優良的晶型，相較於合成溫度140oC、180oC，過低溫導致沒有足夠能量能夠形成完美晶型；過高溫反而破壞晶型、晶隔間距不固定、材料結構不穩定。低溫電漿改質PVDF膜非常成功，表面由疏水性轉為親水性，不但光催化劑更容易塗抹在膜上，膜過濾時也減少積垢阻塞的機率，而光催化薄膜實驗，與未塗抹的改質膜比較確實增加了降解效率，但由於模組設計不良、催化劑塗抹過多，導致整體去除色度效果不佳。

關鍵字

碳量子點 ； 羫基錫酸鋅 ； 染料廢水 ； 低溫電漿 ； 聚偏氟乙烯膜 ； 光催化薄膜

並列摘要

The usage of dye in human life is widely application especially in the fabric, textile industry, paint, and others. Since the rapid development of science and technology, numerous types of dyes are expressed to suffice the demands of modern society, continuously. The dye is designed to resist oxidation, sunlight, and decomposition, that results in high dye stability and is not affected by temperature, light, chemicals, soap, detergent or other living conditions such as sweat and bleaching. The dye wastewater cannot be completely treated by the sewage treatment system. In the present study, photocatalytic and membrane separation techniques were used to prepare photocatalytic thin films. Subsequently, it was used to treat dye wastewater and degradation into by-products safely and easier decomposition, and also to remove chromaticity.
In this study, photocatalyst preparation was carried out by hydrothermal method to make carbon quantum dots (CBDs), with tin tetrachloride (SnCl4 ̇5H2O) and zinc acetate (Zn(CH3COO)2) as tin source and zinc source. The CQDs/ZHS composite photocatalyst was successfully prepared, and the degradation of methyl blue dye 2500 ADMI was investigated with different synthesis temperatures, different CQDs doping amounts, and different experimental doses to find the optimal conditions for the catalyst hydrophobic polyvinylidene fluoride film (PVDF) commercially was used to laboratory low-temperature plasma module for modifying the surface of the membrane and successfully modified from a hydrophobic surface to a hydrophilic surface and the modified membrane was bubbled in the aqueous solution of the catalyst. The vibration is evenly dispersed and the interaction of the van der Waals forces has attached successfully the catalyst to the film. The optimum conditions of photocatalyst were chosen by methyl blue dye. The photocatalytic film was used in the field dye wastewater experiment using the photocatalytic module designed by author. The effect of a photocatalytic film made by CQDs/ZHS composite photocatalyst on color removal was discussed and further improvements.
The experimental results revealed that the zinc bismuth stannate (ZHS) with a synthesis temperature of 160oC has the most stable and excellent crystal form. Low-temperature was occasioned insufficient energy to form a perfect crystal form. High-temperature was caused damaged the crystal form, the interplanar spacing is not fixed, and the material structure is unstable. Low-temperature plasma-modified PVDF membranes were successful and the surface was changed from hydrophobic to hydrophilic. Not only photocatalyst is easier to apply on the membrane, but membrane filtration also reduces the probability of fouling. Whilst, photocatalytic membrane experiments without coated. The modified membrane increased degradation efficiency. However, since the volume of wastewater is high so it is inappropriate in a small design module and excessive dosage catalyst in the application.

並列關鍵字

CQDs ； ZnSn(OH)6 ； Dye waste water ； Low temperature Plasma ； PVDF ； Photocatalytic membrane

參考文獻

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