此篇研究中，我們藉由改變不同種類的界面活性劑、反應溫度及時間來控制奈米合金的大小與外觀型態，使用碘化物(GeI4, NiI2, PdI2)做為我們的前驅物，大幅的降低合金形成溫度，配合最常見的熱注射法進行合成，擁有易調控溫度的優點，可放大反應製程，具有商業化的可能性。目前，已成功合成鍺化鎳(Ge12Ni19)奈米顆粒、鍺化鈀(GePd2)奈米顆粒、奈米柱與奈米線，利用X光繞射圖譜與高解析穿透式電子顯微鏡分析其結晶相態與結晶結構，以及利用掃描式電子顯微鏡觀察奈米材料的大小與形狀。在電觸媒產氫應用上，鍺化鎳奈米顆粒在0.196 cm2電極上產氫電流密度-10 mA/cm2下能達到-190 mV的過電位，耐久性測試採取循環伏安法(cyclic voltammetric, CV)與計時安培分析法(chronoamperometry) ，鍺化鎳奈米顆粒經過10,000個CV循環測試後，其產氫電流密度-10 mA/cm2下的過電位改變量小到可忽略(介於 -189 到 -190 mV vs. RHE)。並且在經過連續24小時測試施加固定電壓-0.6 V中，並無顯現出電流衰退的現象，顯示出鍺化鎳奈米顆粒於0.50 M硫酸是非常的穩定。也將鍺化鎳奈米顆粒應用於5 cm2的工作面積，將所產出的氫氣通入燃料電池，燃料電池於風扇轉動30分鐘間穩定輸出1.47 V 與0.03 A。最後也完成鍺化鈀奈米顆粒、奈米柱及奈米線進行產氫活性測試，通過10000次以上CV循環後，產氫電流密度-10 mA/cm2下的過電位分別為-34、-17及-294 mV vs. RHE，鍺化鈀奈米顆粒與奈米柱經過連續24小時以上測試施加固定電壓-0.5 V中，電流密度並無顯現出衰退的現象，顯示合成的鍺化鈀奈米顆粒與奈米柱於0.50 M硫酸中是非常的穩定。尤其，因為鍺化鈀奈米柱曝露出{221}高活性面使其產氫活性優於市售的鈀黑。

In this study, we controlled the size and morphology of the nanoalloys by changing different species of surfactant, reaction temperature and time. Using iodide (GeI4, NiI2, PdI2) as our precursors substantially reduced the formed temperature of the alloy, with the most common hot-injection approach which has the advantages for simple temperature regulation. It can be scaled up reaction process, and have commercial possibilities. At present, nickel germanide (Ge12Ni19) nanoparticles, palladium germanide (GePd2) nanoparticles, nanorods and nanowires were successfully synthesized and analyzed the phase and structure by X-ray diffraction pattern and high resolution transmission electron microscopy. In the application of electrocatalytic for hydrogen evolution, Ge12Ni19 nanoparticles on 0.196 cm2 electrode exhibited overpotential of -190 mV vs. RHE at a cathodic current density of 10 mA/cm2. The durability was evaluated by cyclic voltammetric (CV) and chronoamperometry. After 10,000 CV cycling, the overpotential achieves current densities of 10 mA/cm2 shows negligible change (from -0.189 to -0.190 V vs. RHE). And after a continuous 24-hour test to apply a static overpotential of 0.6 V vs. RHE, the current density didn’t decrease, showing that the Ge12Ni19 nanoparticles were very stable at 0.50 M sulfuric acid. The Ge12Ni19 nanoparticles were also applied to a working area of 5 cm2; delivered the generating hydrogen gas into the fuel cell, and the fuel cell stable maintained output of 1.47 V and 0.03 A when the fan was rotated as the time between 30 minutes. Finally, the hydrogen evolution activity of GePd2 nanoparticles, nanorods and nanowires were also competely measured. After over 10000 CV cycles, the overpotential achieve current density of -10 mA/cm2 were -34, -17 and -294 mV vs. RHE, respectively. The GePd2 nanoparticles and nanorods didn’t show current density decrease under static overpotential of -0.5 V vs. RHE over 24 hours. These results demonstrate that the synthesized GePd2 nanoparticles and nanorods were fairly stable in the 0.50 M sulfuric acid solution. In particular, the hydrogen evolution activity of GePd2 nanorods are better than commercial palladium black due to the exposure of the high-index {221} facet.

1. (a) Walter, M. G.; Warren, E. L.; McKone, J. R.; Boettcher, S. W.; Mi, Q. X.; Santori, E. A.; Lewis, N. S., Solar Water Splitting Cells. Chem. Rev, 2010, 110 (11), 6446-6473; (b) Lewis, N. S.; Nocera, D. G., Powering the planet: Chemical challenges in solar energy utilization. P. Natl. Acad. Sci. USA, 2006, 103 (43), 15729-15735.
2. Quaino, P.; Juarez, F.; Santos, E.; Schmickler, W., Volcano plots in hydrogen electrocatalysis - uses and abuses. Beilstein J. Nanotech, 2014, 5, 846-854.
3. Jaksic, M. M., Volcano plots along the periodic table, their causes and consequences on electrocatalysis for hydrogen electrode reactions. J. New Mat. Elect. Syst., 2000, 3 (2), 153-168.
4. Bruno, M. M.; Viva, F. A.; Petruccelli, M. A.; Corti, H. R., Platinum supported on mesoporous carbon as cathode catalyst for direct methanol fuel cells. J. Power Sources, 2015, 278, 458-463.
5. Hoang, T. T.; Nguyen, P. H.; Huynh, T. P.; Nguyen, T. V., Enhanced Charge Transfer of Liquid and Gel Electrolytes Using Nano Platinum in Dye-sensitized Solar Cells. Ieee Phot. Spec. Conf., 2013, 2713-2715.
6. Tan, T. L.; Wang, L. L.; Zhang, J.; Johnson, D. D.; Bai, K. W., Platinum Nanoparticle During Electrochemical Hydrogen Evolution: Adsorbate Distribution, Active Reaction Species, and Size Effect. Acs Catal., 2015, 5 (4), 2376-2383.
7. Shinozaki, K.; Zack, J. W.; Pylypenko, S.; Pivovar, B. S.; Kocha, S. S., Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique. J. Electrochem. Soc., 2015, 162 (12), F1384-F1396.
8. Hu, Y. X.; Liu, Y. Z.; Sun, Y. G., Mesoporous Colloidal Superparticles of Platinum-Group Nanocrystals with Surfactant-Free Surfaces and Enhanced Heterogeneous Catalysis. Adv. Funct. Mater., 2015, 25 (11), 1638-1647.
9. (a) Xu, L. X.; Liu, N.; Hong, B.; Cui, P.; Cheng, D. G.; Chen, F. Q.; An, Y.; Wan, C., Nickel-platinum nanoparticles immobilized on graphitic carbon nitride as highly efficient catalyst for hydrogen release from hydrous hydrazine. Rsc Adv., 2016, 6 (38), 31687-31691; (b) Moradi, S. E., Efficient Photocatalytic Hydrogen Evolution by Iron Platinum Loaded Reduced Graphene Oxide. Chem. Biochem. Eng. Q., 2016, 30 (1), 1-7.
10. (a) Asghari, E.; Ashassi-Sorkhabi, H.; Vahed, A.; Rezaei-Moghadam, B.; Charmi, G. R., The use of a hierarchically platinum-free electrode composed of tin oxide decorated polypyrrole on nanoporous copper in catalysis of methanol electrooxidation. Thin Solid Films, 2016, 598, 6-15; (b) Chen, X. X.; Tang, Q. W.; He, B. L.; Lin, L.; Yu, L. M., Platinum-Free Binary Co-Ni Alloy Counter Electrodes for Efficient Dye-Sensitized Solar Cells. Angew. Chem. Int. Edit., 2014, 53 (40), 10799-10803; (c) Wang, R. F.; Liao, S. J.; Fu, Z. Y.; Ji, S., Platinum free ternary electrocatalysts prepared via organic colloidal method for oxygen reduction. Electrochem. Commun., 2008, 10 (4), 523-526.
11. Popczun, E. J.; McKone, J. R.; Read, C. G.; Biacchi, A. J.; Wiltrout, A. M.; Lewis, N. S.; Schaak, R. E., Nanostructured Nickel Phosphide as an Electrocatalyst for the Hydrogen Evolution Reaction. J. Am. Chem. Soc., 2013, 135 (25), 9267-9270.
12. Wang, Y. H.; Zhang, G. X.; Xu, W. W.; Wan, P. B.; Lu, Z. Y.; Li, Y. P.; Sun, X. M., A 3D Nanoporous Ni-Mo Electrocatalyst with Negligible Overpotential for Alkaline Hydrogen Evolution. Chemelectrochem, 2014, 1 (7), 1138-1144.
13. Gong, M.; Dai, H. J., A mini review of NiFe-based materials as highly active oxygen evolution reaction electrocatalysts. Nano Res., 2015, 8 (1), 23-39.
14. Mahesh, K. N.; Balaji, R.; Dhathathreyan, K. S., Palladium nanoparticles as hydrogen evolution reaction (HER) electrocatalyst in electrochemical methanol reformer. Int. J. Hydrogen Energ., 2016, 41 (1), 46-51.
15. Mech, K.; Zabinski, P.; Kowalik, R.; Tokarski, T.; Fitzner, K., Electrodeposition of Co-Pd alloys from ammonia solutions and their catalytic activity for hydrogen evolution reaction. J. Appl. Electrochem., 2014, 44 (1), 97-103.
16. Frank, M. M.; Shang, H.; Rivillon, S.; Amy, F.; Hsueh, C. L.; Paruchuri, V.; Mo, R. T.; Copel, M.; Gusev, E. P.; Gribelyuk, M. A.; Chabal, Y. J., High-kappa gate dielectrics on silicon and germanium: Impact of surface preparation. Sol. St. Phen., 2005, 103-104, 3-6.
17. Vaughn, D. D.; Schaak, R. E., Synthesis, properties and applications of colloidal germanium and germanium-based nanomaterials. Chem. Soc. Rev., 2013, 42 (7), 2861-2879.
18. Buffon, R.; Marochio, I. J.; Rodella, C. B.; Mol, J. C., Germanium and silicon compounds as promoters for Re2O7/SiO2-Al2O3 metathesis catalysts. J. Mol. Catal. A Chem., 2002, 190 (1-2), 171-176.
19. Holman, Z. C.; Liu, C. Y.; Kortshagen, U. R., Germanium and Silicon Nanocrystal Thin-Film Field-Effect Transistors from Solution. Nano Lett., 2010, 10 (7), 2661-2666.
20. Kennedy, T.; Mullane, E.; Geaney, H.; Osiak, M.; O'Dwyer, C.; Ryan, K. M., High-Performance Germanium Nanowire-Based Lithium-Ion Battery Anodes Extending over 1000 Cycles Through in Situ Formation of a Continuous Porous Network. Nano Lett., 2014, 14 (2), 716-723.
21. Mao, L. F., Dot size effects of nanocrystalline germanium on charging dynamics of memory devices. Nanoscale Res. Lett., 2013, 8.
22. Rosenfeld, G., Spectrophotometric Determination of Germanium in Biological Materials. Anal. Biochem., 1960, 1 (6), 469-477.
23. Ma, X. C.; Wu, F. Y.; Kauzlarich, S. M., Alkyl-terminated crystalline Ge nanoparticles prepared from NaGe: Synthesis, functionalization and optical properties. J. Solid State Chem., 2008, 181 (7), 1628-1633.
24. Taylor, B. R.; Kauzlarich, S. M.; Delgado, G. R.; Lee, H. W. H., Solution synthesis and characterization of quantum confined Ge nanoparticles. Chem. Mater., 1999, 11 (9), 2493-2500.
25. Paduani, C., Electronic structure and Fermi surfaces of the superconductive A(3)B compounds: A = V, Nb; B = Ga, Ge and Sn. Solid State Commun., 2009, 149 (31-32), 1269-1273.
26. Mirmelsteyn, A. V.; Karkin, A. Y.; Arkhipov, V. Y.; Voronin, V. I., Superconductivity and Phonon-Spectrum Softening in Mo3ge Compounds after Fast-Neutron Irradiation. Fiz. Met. Metalloved., 1984, 58 (5), 1008-1011.
27. Sato, T.; Sakata, M., Magnetic and Electrical-Properties of Crge and Cr11ge8. J. Phys. Soc. Jpn., 1983, 52 (5), 1807-1813.
28. Lebech, B.; Bernhard, J.; Beckman, O., The Low-Temperature Magnetic-Structure of Hexagonal Fege. Acta Crystallogr. A, 1984, 40, C260-C260.
29. DiTusa, J. F.; Zhang, S. B.; Yamaura, K.; Xiong, Y.; Prestigiacomo, J. C.; Fulfer, B. W.; Adams, P. W.; Brickson, M. I.; Browne, D. A.; Capan, C.; Fisk, Z.; Chan, J. Y., Magnetic, thermodynamic, and electrical transport properties of the noncentrosymmetric B20 germanides MnGe and CoGe. Phys. Rev. B, 2014, 90 (14).
30. Castrucci, P.; Pinto, N.; Morresi, L.; Gunnella, R.; Murri, R.; Scarselli, M.; De Crescenzi, M., Magnetic properties of thin MnGe films investigated by magnetic force microscopy. J. Magn. Magn. Mater., 2004, 272, E1541-E1543.
31. Ohyanagi, T.; Kitamura, M.; Araidai, M.; Kato, S.; Takaura, N.; Shiraishi, K., GeTe sequences in superlattice phase change memories and their electrical characteristics. Appl. Phys. Lett., 2014, 104 (25).
32. Sun, Z. M.; Pan, Y. C.; Sa, B. S.; Zhou, J., Ab initio study on hexagonal Ge2Sb2Te5-a phase-change material for nonvolatile memories. Functional and Electronic Materials 2011, 687, 7-11.
33. Frumar, M.; Wagner, T., Ag doped chalcogenide glasses and their applications. Curr. Opin. Solid St M., 2003, 7 (2), 117-126.
34. Kannan, E. S.; Bisotto, I.; Portal, J. C.; Murali, R.; Beck, T. J., Photovoltage induced by ratchet effect in Si/SiGe heterostructures under microwave irradiation. Appl. Phys. Lett., 2011, 98 (19).
35. Kumar, M.; Umezawa, N.; Imai, M., (Sr,Ba)(Si,Ge)(2) for thin-film solar-cell applications: First-principles study. J. Appl. Phys., 2014, 115 (20).
36. Shein, A. B.; Zubova, E. N., Electrochemical behavior of Mn5Si3 and Mn5Ge3 in sulfuric acid solutions. Russ. J. Electrochem., 2004, 40 (2), 195-199.
37. Shein, A. B.; Aitov, R. G., Electrochemical-Behavior of Eutectic Metal Germanium Alloys in Sulfuric-Acid. Electrochim Acta, 1991, 36 (8), 1247-1251.
38. Komatsu, T.; Fukui, M.; Yashima, T., Cobalt intermetallic compounds for selective hydrogenation of acetylene. In Studies in Surface Science and Catalysis, Joe W. Hightower, W. N. D. E. I.; Alexis, T. B., Eds. Elsevier: 1996; Vol. Volume 101, pp 1095-1104.
39. (a) Fink, C. G.; Dokras, V. M., Electrodeposition and Electrowinning of Germanium. J Electrochem Soc 1949, 95 (2), 80-97; (b) Kawashima, A.; Kanda, T.; Hashimoto, K., Amorphous Alloy Catalysts for Electro-Oxidation of Methanol and Its Derivatives in a Sulfuric-Acid Solution. Mater. Sci. Eng., 1988, 99, 521-524.
40. Vanderplas, J. F.; Barendrecht, E., Electrocatalytic Hydrogenation Processes Controlled Potential .1. The Electrocatalytic Reduction of Nitric-Acid. Electrochim Acta, 1980, 25 (11), 1463-1469.
41. Al-Joubori, A. A.; Suryanarayana, C., Synthesis of metastable NiGe2 by mechanical alloying. Mater. Design, 2015, 87, 520-526.
42. Okamoto, H., The Ge-Pd system (germanium-palladium). Journal of Phase Equilibria 1992, 13 (4), 410-413.
43 Volz, T. J.; Hanson, G. R.; Fleckenstein, A. E., Measurement of kinetically resolved vesicular dopamine uptake and efflux using rotating disk electrode voltammetry. J. Neurosci. Meth., 2006, 155 (1), 109-115.