本研究使用磁控式濺鍍系統，在不需要額外的化學添加物，如化學還原劑、包覆劑、穩定劑等狀況下，利用離子溶液—1-n-butyl-3-methylimidazolium hexafluorophosphate（BMIPF6）作為液態基材，用以製備單金屬與雙金屬奈米粒子。製備方式包含依序濺鍍與混合不同金屬奈米粒子之離子溶液，再行真空熱退火處理。所得之金屬奈米粒子以穿透式電子顯微鏡明視野影像觀察濺鍍速率對粒徑與型態的差異，並利用HRTEM晶格影像分析雙金屬奈米粒子中，不同成分對晶格常數的影響，輔以能量散失能譜定性、定量分析雙金屬奈米粒子成分比例，與以紫外光/可見光光譜分析表面電漿共振帶變化分析雙金屬奈米粒子。

實驗結果證實不論使用依序濺鍍或真空熱退火處理混合不同金屬奈米粒子的離子溶液，其雙金屬奈米粒子結構皆呈現合金或是部分合金與部分純金屬的結構。空氣中熱氧化單金屬奈米粒子，結果呈現中央為金屬奈米粒子，外圍為氧化物的核殼結構奈米粒子。表面電漿共振帶的偏移變化與單一特性吸收峰亦證明雙金屬奈米粒子為合金或核殼結構。另外，溫度對離子溶液中金屬奈米粒子的影響也藉由TEM明視野影像與表面電漿共振帶的變化得知，熱處理增加金屬奈米粒子粒徑，最後使表面電漿共振帶偏移寬化。

本研究最後以化學方式製備雙金屬奈米粒子，以紫外光輔助反應，於含銅金屬奈米粒子之離子溶液中還原四氯金酸得金原子，並使之沉積於金屬奈米粒子表面而形成雙金屬奈米粒子，藉TEM、HRTEM、EDS與UV-Vis 光譜證實，以此方法所得之雙金屬奈米粒子為核殼結構，並具多面體幾何形狀。

Sputter deposition of metal into ionic liquid (ILs) resulted in the formation of metal nanoparticles, without using additional chemical species, such as reducing, capping and/or stabilizing agents. Taking ILs (1-n-butyl-3-methyllimidazlium hexafluorophosphate, BMIPF6) as liquid substrate, metal nanoparticles were formed after metal clusters became stable by adsorbing anion of ILs. Nanoparticles were synthesized in ILs by sequential sputter deposition of different metals, and mixing different metal nanoparticles followed by annealing in vacuum. Effect of sputtering rate to the structure and the diameter distribution of bimetallic nanoparticles is examined using TEM bright - field images assisted with EDS. The influence in composition on metals to lattice parameters is carried out by HRTEM lattice images.

Alloy and/or mixture of alloy and pure metal were formed by both the sequential sputter deposition, and blending metal nanoparticles followed by annealing in vacuum. Thermal oxidation of metal nanoparticles resulted a core-shell structure that is composed with metal in the center and surrounded by oxide compound. The bimetallic nanoparticles caused shifting and changing of SPR bands. Also, the effect of temperature on the metal nanoparticles was observed from TEM bright – field images and the changes of SPR bands, which were related with diameters of metal nanoparticles.

Finally, bimetallic metal nanoparticles were prepared by the photochemical reduction and deposition of Au precursor on the metal nanoparticles as seeds in ILs. TEM bright - field images, HRTEM lattice images HRTEM, EDS and UV-vis spetrum have been used to characterize the structure and optical properties of bimetallic nanoparticles. Comparing with sequential sputter method, the results show that the structure of bimetallic nanoparticles are core-shell structure.

參考文獻
[1] Y. Yang, J. Shi, G. Kawamura and M. Nogami, “ Preparation of Au-Ag, Ag-Au Core-shell Bimetallic Nanoparticles for Surface-enhanced Raman Scattering ”, Scripta Materialia, 58, pp.862-865 (2008).
[2] K.-I. Okazaki, T. Kiyama, K. Hirahara, N. Tanaka, S. Kuwabata and T. Torimoti, “ Single-step Synthesis of Gold-silver Alloy Nanoparticles in Ionic Liquids by A Sputter Deposition Dechnique “, Chemical. Communications, pp.691-693 (2008).
[3] O. P. Khatri, K. Adachi, K. Murase, K.-I. Okazaki, T. Torimoto, N. Tanaka, S. Kuwabata and H. Sugimura, “ Self-assembly of Ionic Liquid （BMI-PF6）- Stabilized Gold Nanoparticles on A Silicon Surface: Chemical and Structural Aspects”, Langmuir, 24, pp.7785-7792 (2008).
[4] 馬振基，奈米材料科技原理與應用，全華科技圖書股份有限公司，台北市（民92年）。
[5] 張仕欣，王崇人，「金屬奈米粒子的吸收光譜」，化學，第56卷第3期，pp.209-222 (1998)。
[6] 吳民耀，劉威志，「表面電漿子理論與模擬」，物理雙月刊，第二十八卷二期，pp.486-496。
[7] 邱國斌，蔡定平，「金屬表面電漿簡介」，物理雙月刊，第二十八卷二期，pp.472-485。
[8] W. L. Barnes, A. Dereux, and T.. W. Ebbesen, “ Surface Plasmon Subwavelength ”, Nature, pp.424, 824 (2003).
[9] P. Drude, “ Zur Elektronentheorie der Metalle ”, Ann. Der Physik, 1(566); 3(369) (1900).

[10] C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles, Wiley-VC, NY, USA (1983).
[11] G. Mie, “ Contribution to the Optics of Turbid Media, Particularly Colloidal Metal solutions “, Annals of. Physics., 25, pp.377-445 (1908).
[12] F. Xiao, F. Zhao, J. Li, L. Liu and B. Zeng, “ Characterization of Hydrophobic Ionic Liquid-carbon Nanotubes-gold Nanoparticles Composite Film Coated Electrode and the Simultaneous Voltammetric Determination of Guanine and Adenine ”, Electrochimica Acta, 53, pp.7781-7788 (2008).
[13] A. P. Philipse, G. J. Vroege, “ Phase Behavior of Mixture of Magnetic Colloids and Non-adsorbing Polymer ”, Available: www.library.uu.nl/digiarchief/dip/diss/1942669/full.pdf.(1963)
[14] N. Cui, P. He, L. J. Luo, “ Magnesium-based Hydrogen Storage Materials Modified by Mechanical Alloying”, Acta Materialia, 47, pp.3737-3743 (1999).
[15] N. Toshima, M. Harada, T. Yonezawa, K. Kushihashi and K. Asakura, “ Structural Analysis of Polymer-protected Palladium/platinum Bimetallic Clusters as Dispersed Catalysts by Using Extended X-ray Absorption Fine Structure Spectroscopy ”, Journal of Physical Chemistry, 95, pp.7448 (1991).
[16] N. Toshima, M. Harada, T. Yonezawa and K. Asakura, “ Catalytic Activity and Structural-Analysis of polymer-Protected Au-Pd Bimetallic Cluster Prepared by the Simultaneous Reduction of HAuCl4 and PdCl2 ”, Journal of Physical Chemistry, 96, pp.9927 (1992).

[17] M. Harada, K. Asakura and N. Toshima, “ Catalytic Activity and Structural Analysis of Polymer-protected Gold/palladium Bimetallic Clusters Prepared by the Successive Reduction of Hydrogen Tetrachloroaurate(III) and Palladium Dichloride ”, Journal of Physical Chemistry, 97, 5103 (1993).
[18] 陳浩銘，「具核-殼結構之金屬奈米粒子合成及其特性分析」，碩士論文，國立台灣大學，台北市(2004)。
[19] S. W. Han, Y. Kim and K. Kim, “ Dodecanethiol-Derivatized Au/Ag Bimetallic Nanoparticles-TEM, UV/VIS, XPS, and FTIR Analysis “ Journal of Colloid and Interface Science, 208, pp.272-278 (1998).
[20] M. Moskovits, I. Srnova-Sloufova, B. Vlckova, “ Bimetallic Ag-Au Nanoparticles: Extracting Meaningful Optical Constants from the Surface-Plasmon Extinction Spectrum ”, Journal of Chemical Physics, 116, pp.10435-10448 (2002).
[21] S. Link, Z. L. Wang and M. A. El-Sayed, “ Alloy Formation of Gold-Silver Nanoparticles and the Dependence of the Plasmon Absorption on their Composition ”, Journal of Physical Chemistry B, 103, 3529 (1999).
[22] 林芳新，董瑞安，「奈米核殼複合粒子的製備及生醫應用」，科儀新知，第二十八卷第一期，pp.7-15，（民95年8月）。
[23] 王宏文，林孟萱，「Core-Shell 奈米粒子的合成技術」，工業材料，190，pp.96-104（民91年10月）。
[24] 陳東煌，（2003），「複合奈米粒子的製備與應用」，化工技術，120，180。

[25] H. M. Chen, R. S. Liu, L. -Y. Jang, J. –F. Lee and S. F. Hu, “ Characterization of Core-shell Type and Alloy Ag/Au Bimetallic Clusters by Using Extended X-ray Absorption Fine Structure Spectroscopy ”, Chemical Physics Letters, 421, pp.118-123 (2006).
[26] S. Remita, G. Picq, J. Khatouri, M. Mostafavi, “ Radiolytic Formation of Bilayered Ptcore/Aushell and Aucore/Ptshell Clusters in Aqueous Solution “, Radiation Physics and Chemistry, 54, pp.463-473 (1999).
[27] H. Han, Y. Fang, Z. Li and H. Xu., “ Tunable Surface Plasma Resonance Frequency in Ag core/Au shell Nanoparticles System Prepared by Laser Ablation “, Applied Physics Letters 92, 023116 (2008).
[28] 李汝雄編著，綠色溶劑 — 離子液體的合成與應用，化學工業出版社，北京(2005)。
[29] T. Welton, “ Room-Temperature Ionic Liquids. Solvents for Synthesis and Catalysis ”, Chemical Reviews, 99, pp.2071-2083 (1999).
[30] J. A. Boon, J. A. Levisky, J. L. Pflug and J. S. Wilkes, “ Friedel-Crafts Reactions in Ambient-temperature Molten Salts ”, Journal of Organic Chemistry, 51, pp.480-483 (1986).
[31] Y. Chauvin, L. Mussmann and H. Olivier, “A Novel Class of Versatile Solvents for Two-Phase Catalysis: Hydrogenating, Isomerization, and Hydroformylation of Alkenes Catalyzed by Rhodium Complexes in Liquid 1,3-Dialkylimidazolium Salts”, Angewandte Chemie Internation Edition English, 34, pp.2698 (1995).
[32] D. W. Armstrong, L. –K. Zhang, L. He and M. L. Gross, “ Ionic Liquids as Matrixes for Matrix-Assisted Laser DEsorption/Ionization Mass Spectrometry”, Analytical Chemristry, 73, pp.3679-3686 (2001).
[33] S. Carda-Broch, A. Berthod and D. W. Armstrong, “ Ionic Matrices for Matrix-assisted Laser Desorption/ionization Time-of-flight Detection of DNA Oligomers ”, Rapid Communications in Mass Spectrometry, 17, pp.553-560 (2003).
[34] G. –T. Wei, J. C. Chen and Z. Yang, “ Studies on Liquid/liquid Extraction of Copper Ion with Room Temperature Ionic Liquid ”, Journal of the Chinese Chemical Society, 50, pp.1123-1130 (2003).
[35] G. –T. Wei, J. C. Chen and Z. Yang, “ Room Temperature Ionic Liquid as A Novel Medium for Liquid/liquid Extraction of Metal Ions ”, Analytica Chimica Acta, 488, pp.183 (2003).
[36] A. E. Visser, R. P. Swatloski and R. D. Rogers, “pH-Dependent Partitioning in Room Temperature Ionic Liquids Provides A Link to Traditional Solvent Extraction Behavior”, Green Chemistry, 2, pp.1 (2000).
[37] G. –T. Wei, Z. Yang, C. Y. Lee, H. Y. Yang and C. R. Chris Wang, “ Aqueous-Organic Phase Transfer of Gold Nanoparticles and Gold Nanorods Using an Ionic Liquid ”, Journal of the American Chemical Society, 126, pp.5036-5037 (2004).
[38] D. R. Macfarlane, J. Huang and M. Forsyth, “ Lithium-Doped Plastic Crystal Electrolytes Exhibiting Fast Ion Conduction for Secondary Batteries ”, Nature, 402, pp.792-794 (1999).
[39] M. Doyle, S. K. and G. Proulx, “High-Temperature Proton Conducting Membranes Based on Per fluorinated Ionomer Membrane-Ionic Liquid Composites ”, Journal of Electrochemical Society, 147, pp.34-37 (2000).

[40] W. Kubo, T. Kitamura, K. Hanabusa, Y. Wada and S. Yanagida, “ Quasi-Solid Dye-Sensitized Solar Cells Using Room Temperature Molten Salts and A Low Molecular Weight Gelator”, Chemical Communications, pp.374-375 (2002).
[41] T. J. Boyle, D. Ingersoll, M. A. Rodriguez, C. J. Tafoya and D. H. Doughty, “ An Alternative Lithium Cathode Material: Synthesis, Characterization, and Electrochemical Analysis of Li8(Ni5Co2Mn)O16 ” , Journal of Electronchemical Society, 146, pp.1683-1686 (1999).
[42] M. C. Buzzeo, O. V. Klymenko, J. D. Wadhawan, C. Hardacre, K. R. Seddon and R. G. Compton, “ Voltammetry of Oxygen in the Room-Temperature Ionic Liquids 1-Ethyl-3-methylimidazolium Bis((trifluoromethyl)sulfonyl)imide and Hexyltriethylammonium Bis((trifluoromethyl)sulfonyl)imide: One-Electron Reduction To Form Superixide. Steady-State and Transient Behavior in the same Cycli Coltammogram Resulting from Widely Different Diffusion Coefficients of Oxygen and Superoxide ”, Journal of Physical Chemistry A, 107, pp.8872-8878 (2003).
[43] I. M. AlNashef, M. L. Leonard, M. C. Kittle, M. A. Matthews and J. W. Weidner, “ Electrochemical Generation of Superoxied in Room-Temperature Ionic Liquids ”, Electrochemical Solid-State Letters, 4, D16 (2001).
[44] D. Giovanelli, M. C. Buzzeo, N. S. Lawrence, C. Hardacer, K. R. Seddon and R. G. Compton, “ Determination of Ammonia Based on the Electro-oxidation of Hydroquinone in Dimethylformamide or in the Room Temperature Ionic Liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ”, Talanta, 62, pp.904-911 (2004).

[45] M. C. Buzzeo, C. Hardacre and R. G. Compton, “ Use of Room Temperature Ionic Liquids in Gas Sensor Design ”, Analytical Chemistry, 76, pp.4583-4588 (2004).
[46] R. P. Swatloski, S. K. Spear, J. D. Hollbrey and R. D. Rogers, “ Dissolution of Cellose with Ionic Liquids ”, Journal of the American Chemical Society, 124, pp.4974 (2002).
[47] Y. Liu, M. Wang, Z. Li, H. Liu, P. He and J. Li., “ Preparation of Porous Aminopropylsilsesquioxane by A Nonhydrolytic Sol-Gel Method in Ionic Liquid Solvent ”, Langmuir, 21, pp.1618-1622 (2005).
[48] C. Ye, W. Liu, Y. Chen and L. Yu, “ Room-temperature Ionic Liquids: A Novel Versatile Lubricant ”, Chemical Communications, pp.2244-2245 (2001).
[49] F. H. Hurley and T. .P. WIer, “ Electrodeposition of Materials from Fused Quatermary Ammonium Salts ”, Journal of the Electrochemical Society, 98, pp.203-206 (1951).
[50] J. S. Wilkes, J. A. Levisky, R. A. Wilson and C. L. Hussey, “ Dialkylimidazolium Chloroaluminate Melts: A New Class of Room-Temaperature Ionic Liquids for Electrochemistry, Spectroscopy, and Synthesis ”, Inorganic Chemistry., 21, P1263-1264 (1982).
[51] M. Freemantle, “ Designer Solvents: Ionic Liquids may Boost Clean Technology Development, ”. Chemical & Engineering News, 76(13), pp. 32-37 (March 30, 1998).
[52] J. S. Wilkes, “ A Short History of Ionic Liquids—from Molten Salts to Neoteric Solvents ”, Green Chemistry, 4, pp.73-80 (2002).

[53] J. D. Holbery and K. R. Seddon, “ Ionic Liquids ”, Clean Products and Processes, 1, pp. 223 (1999).
[54] D. A. Skoog, F. J. Holler and T. A. Nieman, Principles of Instrumental Analysis, Thomson Learning, USA (1997).
[55] D. B. Williams and C. B. Carter, Transmission Electron Microscopy: A Textbook for Materials Science, Plenum Press, NY, USA (1996).
[56] 陳力俊，材料電子顯微鏡學，財團法人國家實驗研究院儀器科技研究中心，新竹市(1994)。
[57] 鮑忠興，劉思謙，近代穿透式電子顯微鏡實務，滄海書局，台中市(2008)。
[58] B. D. Cullity and S. R. Stock., Elements of X-ray Diffravtion, Prentice-Hall, USA (2001).
[59] T. Torimoto, K.-I. Okazaki and T. Kiyama, “ Sputter Deposition onto Ionic Liquids: Simple and Clean Synthesis of Highly Dispersed Ultrafine Metal Nanoparticles ”, Applied Physics Letters, 89, 243117 (2006).
[60] R.. H. Doremus, “ Optical Properties of Small Silver Particles ”, Journal of Chemical Physics, 42, 1, pp.414-417 (1965).
[61] I. Lisiecki, F. Billoudet and M. P. Pileni, “ Control of the Shape and the Size of Copper Metallic Particles ”, Journal of Physical Chemistry, 100, pp.4160-4166 (1996).
[62] N.V. Tarasenko, V. S. Burakov and A. V. Butsen, “ Laser Ablation Plasma in Liquids for Fabrication of Nanosize Particles ”, Publications of the Astronomical Observatory, Belgrade, 82, pp.201-211 (2007).

[63] G. Compagnini, E. Messina, O. Puglisi, R. S. Cataliotti and V. Nicolosi, “ Spectroscopic Evidence of A Core-shell Structure in the Earlier Formation Stages of Au-Ag Nanoparticles by Pulsed Laser Ablation in Water ”, Chemical Physics Letters, 457, pp.386-390 (2008).
[64] A. Zhang, J. Zhang and Y. Fang, “ Photoluminescence from Colloidal Silver Nanoparticles ”, Journal of Luminescence, 128, pp.1635-1640 (2008).
[65] R. H. Doremus, “ Optical Properties of Small Gold Particles ”, Journal of Chemical Physics, 40, pp.2389-2396 (1963).
[66] R. Doremus, S. -C. Kao and R. Garcia, “ Optical Absorption of Small Copper Particles and the Optical Properties of Copper ”, Applied Optics, 31, pp.27 (1992).
[67] A. R. Denton and N. W. Ashcroft, “ Vegard’s Law ”, Physical Review A, 43, pp.3161-3164 (1991).
[68] J. Zhu, Y. Shen, A. Xie, L. Qiu, Q. Zhang and S. Zhang, “ Photoinduced Synthesis of Anisotropic Gold Nanoparticles in Room-Temperature Ionic Liquid ”, Journal of Physical Chemistry C, 111, pp.7629-7633 (2007).
[69] A. Rai, M. Chaudhary, A. Ahmad, S. Bhargava and M. Sastry, “ Synthesis of Triangular Au core- Ag Shell Nanoparticles ”, Materials Research Bulletin, 42, pp. 1212-1220 (2007).