在現今的移除有機汙染物的技術中，光觸媒是一項高效率且備受關注的一項方法，本論文以二硫化鉬(Molybdenum disulfide, MoS2)作為光觸媒基底材料進行後續改質研究以及降解染料實驗。本研究以水熱法製程成功合成奈米花狀二硫化鉬結構，接著使用光化學還原法將金奈米顆粒還原於具有高表面積的二硫化鉬奈米米花表面上，透過異質結構設計與引入表面電漿共振效應，使材料能夠有效利用波長450 nm - 750 nm的入射光。接著，以化學還原法將硫化銅作為外殼沉積在金奈米顆粒表面形成核殼結構(MoS2/Au@CuS)，使其發揮硫化銅所具有的類芬頓特性，有利於在黑暗環境下高效地降解有機染料。降解實驗部分通過照射580 nm的光源，MoS2/Au@CuS異質結構表現出高效的降解亞甲基藍染劑的光觸媒能力，而在關閉光源的情況下，染劑溶液仍然可以穩定降解。此外還以開燈/關燈的先後順序及持續時間來模擬日夜變化中光暗輪替的情形，通過探討動力學模型與捕捉劑試驗，研究了相關的光暗降解機制，並且發現開燈/關燈的順序以及時長對降解效率有著決定性的作用。
本實驗利用SEM、EDS、TEM、XRD、Raman、PL、UV-Vis、FT-IR、XPS以及電化學量測對所合成之奈米複合物的微結構、表面形態、光學特性、鍵結和電化學性質進行了觸媒物化特性分析。經SEM分析，本研究自製之觸媒形成由片狀結構團聚而成的奈米花，且確認了奈米金與硫化銅的附著情形，使用EDS與HRTEM觀察到二硫化鉬具備層狀結構，而金與硫化銅則互相形成核殼結構，以Raman分析位於365 cm-1(E_2g^1)及406 cm-1(A_1g)的峰值出現偏移，表明了複合結構摻雜型態的改變，並以此推算二硫化鉬層數，透過XRD分析硫化參數與晶體結構間的關係，使用PL與UV分析螢光峰值強度變化與可見光吸收峰，說明觸媒材料的能隙變化，接著在FT-IR與XPS中分析產物中存在的分子鍵結以及各元素存在形式，而降解染劑實驗部分則以量測亞甲基藍可見光吸收圖譜變化用以討論觸媒降解能力。

SUMMARY
MoS2 has been considered highly potential 2D semiconductor material due to its direct and tunable band gap phenomena which has been widely applied on solar cells, hydrogen evolution and photocatalyst. In this study, Au nanoparticles have been directly on MoS2 nanoflowers with high surface areas, and then CuS layer as shells was deposited on Au surfaces to form a core-shell structures, which enables to absorb light with a wider range of wavelength and facilitates the efficient degradation of organic dyes under dark environment. By irradiating 450 nm of UV light, MoS2/Au@CuS heterostructures demonstrate high photocatalyst ability to degrade Methyl Blue (MB), and the remaining MB solution was kept degraded after turning off the light source. The involved photocatalyst mechanism was examined by kinetic study, scavenger test and microstructural investigations. We found that the light-on/light-off sequence acts as decisive role on the degradation efficiency, which was validated with quantitative kinetic characterizations.
Key words : Molybdenum disulfide, photo-catalysis, dark-catalysis, core-shell structure, dyes degradation

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