水熱法合成二硫化鉬奈米結構之材料與光觸媒特性研究

Materials Characterization and Photocatalytic Activity of Molybdenum Disulfide Nanostructure Synthesized by Hydrothermal Method

張維恩(Chang, We En)

指導教授 ： 吳志明

國立清華大學/工學院/材料科學工程學系/碩士(2015年)

摘要

本論文使用水熱法製程成功合成奈米花形貌二硫化鉬(Molybdenum disulfide, MoS2)粉末，藉由添加1-丁基-3-甲基咪唑氯化鹽(1-butyl-3-methylimidazolium chloride salt, BMIM[Cl])離子液體使得單顆花朵形貌更加明顯，並利用FESEM、HRTEM、XRD、Raman討論其表面形貌、材料結構及化學性質等等，接著針對分析結果討論二硫化鉬光觸媒在可見光(400 < λ < 775 nm)下降解羅丹明(Rhodamine)染料的能力達到90 %。
本研究使用二水鉬酸鈉(Sodium molybdenum oxide dehydrate, Na2MoO4‧2H2O)以及硫脲(Thiourea, CH4N2S)分別作為二硫化鉬之鉬原子及硫原子前驅物，並且添加BMIM[Cl]作為單顆球狀成核區。利用BMIM[Cl]介面活性劑在水中容易解離成離子特性，因[BMIM]+為一種疏水基容易團聚成球狀，使MoO42-透過電荷相吸附著在球狀[BMIM]+，接著S2-再與Mo4+鍵結形成片狀結構，整段製程皆利用水熱法製程持溫一段時間完成。經FESEM分析，當BMIM[Cl]濃度增加時二硫化鉬奈米花尺寸隨之增加，經XRD分析得知結構為 2H-MoS2 (JCPDS Card No.37-1492)，經HRTEM分析，觀察得到二硫化鉬具備層狀結構，經Raman分析，峰值383 cm-1 (E12g)與 408 cm-1 (A1g)出現偏移。

關鍵字

水熱法 ； 二硫化鉬 ； 奈米結構 ； 1-丁基-3-甲基咪唑氯化鹽 ； 光觸媒

並列摘要

In this study, MoS2 (Molybdenum disulfide) nanoflowers have been synthesized by hydrothermal method with adding 1-butyl-3-methylimidazolium chloride salt (BMIM[Cl]) ionic liquid as surface active agent. The materials characterization of the MoS2 nanoflowers were performed by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), and Raman spectroscopy to investigate the surface morphology, material structure, and chemical properties. On the basis of our results, the photocatalytic activity of MoS2 for decomposing Rhodamine B (RhB) solution under visible light (400 < λ < 775 nm) can be reached 90 % under visible-light illumination.
The sodium molybdenum oxide dehydrate (Na2MoO4‧2H2O) and thiourea (CH4N2S) were acted as precursor of MoS2. The BMIM[Cl] was dissolved in DI water to form [BMIM]+ ionic liquid with hydrophobic property, therefore MoO42- adsorbed on [BMIM]+ spheres to grew the MoO42- spheres. After that, the S2- reacted with Mo4+ to form MoS2 nanoflowers. The process was performed by hydrothermal method. FESEM images showed that the size of MoS2 nanoflowers increases with increasing the concentration of BMIM[Cl]. The XRD pattern indicated the nanoflowers belong to 2H-MoS2 structure (JCPDS Card No.37-1492).The HRTEM showed layer by layer structure. The Raman patterns showed that the 383 cm-1 (E12g) and 408 cm-1 (A1g) modes have been observed.

並列關鍵字

hydrothermal method ； MoS2 (Molybdenum disulfide) ； nanostructure ； 1-butyl-3-methylimidazolium chloride salt (BMIM[Cl]) ； photocatalysis

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