近年來由於科技的快速發展，奈米材料在許多技術突破上扮演著非常重要的角色。由於奈米複合材料擁有一些複合性質，如物理及光學性質以及其性質的加成性等…所以複合材料的開發在廣為被科學家所研究。而在材料科學中，因為其特殊的光學及物理特性，奈米銀粒子及奈米二氧化鈦都是相當常被科學家研究之材料，如銀粒子在奈米維度時會產生表面電漿共振 (surface Plasmon)，以及二氧化鈦在吸收紫外光波段後產生之光觸媒特性 (photocatalyst)。二氧化鈦奈米粒子在太陽能領域及環境工程亦有見的應用，如: 染料敏化電池 (Dye-sensitzied solar cell) 及光觸媒分解有機污染物 (decomposition of organic pollutant) 。此篇研究主要探討奈米銀、奈米二氧化鈦、其複合材料之合成與其光電性質之應用。在奈米銀粒子合成中，主要探討的內容為保護劑(protecting agent)之比較及影響，而選用之奈米保護劑主要為 β-環糊精 (β-cyclodextrin)、氧化石墨烯 (graphene oxide)以及聚乙烯亞胺 (Polyethylenimine )。而在使用此三種奈米銀保護劑，均可合成穩定之球狀奈米銀顆粒，但在其中只有使用乙烯亞胺為保護劑可以合成高濃度之奈米銀顆粒。結果顯示在以此三種保護劑合成之奈米粒子之狀況下，氧化石墨烯為保護劑時可以產生較高的奈米銀還原比(意即較多的奈米銀粒子從銀陽離子被還原)再來則是β-環糊精而聚乙烯亞胺則為最低。而在奈米二氧化鈦之合成中，主要採取的是溶膠法 (sol-gel)，在合成過程中縮合 (condensation) 之溫度以及其晶相與溫度的關係亦是探討之內容。此實驗中，奈米二氧化鈦與其的奈米銀、奈米金之複合材料亦被應用於染料敏化電池之電極上。應用的部分，主要利用奈米二氧化鈦在紫外光波段下之光電特性產生電流，此應用並不同於以往以染料來吸收光來產生電流，而是利用二氧化鈦的光電特性來產生電流。另外，奈米二氧化鈦及其複合材料與導電玻璃 (conductive glass) 之燒結溫度對太陽能電池之表現、不同保護劑合成之奈米銀與二氧化鈦之複合材料為電極時的電池表現、使用染料與不使用染料的比較以及不同電解液溶劑之比較，亦是主要被探討的內容。

Nanocomposites are now becoming a very welcomed type of morphology in material science because they have some different physical and optical properties from the single compound nanomaterial. In this research, the Ag and TiO2 nanoparticles are mainly focused. For the synthesis of Ag nanoparticle, the different kinds of protecting agents are chosen, such as β-cyclodextrin (β-CD), graphene oxide (GO) and polyethyleneimine (PEI), and the spherical Ag nanoparticle can be obtained. Moreover, the results also show that the polyethyleneimine can greatly stabilize high concentration of Ag nanoparticle and the reduction of Ag by reducing agent occurred in the order of GO > β-CD > PEI. The sol-gel method was chosen to synthesize TiO2 nanoparticle, and the various temperatures on calcination shows that the different crystallizations and morphologies can be obtained. In addition, the Ag-TiO2 nanocomposite was synthesized by different methods (A and B), and Ag-TiO2 synthesized by method A showed Ag-TiO2 core-shell-like nanostructure. Furthermore, the prohibition of hydrolysis of titanium isoprorproproxide by acetylacetone was shown, and the rate of hydrolysis increased with increased temperature. The TiO2, Ag-TiO2 and Au-TiO2 were applied as electrodes of Dye-sensitized solar cell (DSSC) under UV irradiation. In the difference with conventional DSSC, this experiment was performed under UV irradiation, and the results showed that the TiO2 plays not only a role as semiconductor to transfer electron from dye and adsorb the dye but also a photo accepter to generate electrons. Furthermore, the results of comparison of electrolytes between NMP (N-methy-2-pyrrolidone) and DMF (dimethylformamide) showed that the DMF as electrolyte can obtain higher performance than NMP on DSSC. The results were also shown about the sintering temperature of electrode of DSSC at 200 to 460 oC. Namely, the higher performance of DSSC can be obtained when increasing the sintering temperature in such range. The performance of electrodes was in the order of TiO2 > Ag-β-CD-TiO2 > Ag-PEI-TiO2.

[1] E. Hutter, J. H. Fendler and D. Roy, “Surface Plasmon Resonance Studies of Gold and Silver Nanoparticles Linked to Gold and Silver Substrates by 2-Aminoethanethiol and 1,6-Hexanedithiol,” J. Phys. Chem. B, vol. 105, pp. 11159-11168, 2001.
[2] J M Pitarke, V M Silkin, E V Chulkov, and P M Echenique “Theory of surface plasmons and surface-plasmon Polaritons” Rep. Prog. Phys., vol. 70, pp.1–87, 2007.
[3] Sally D. Solomon, Mozghan Bahadory, Aravindan V. Jeyarajasingam, Susan A. Rutkowsky and Charles Boritz, “Synthesis and Study of Silver Nanoparticles,” Journal of Chemical Education, vol. 84, No. 2, 2007.
[4] R. Griffith Freeman, Michael B. Hommer, Katherine C. Grabar, Michael A. Jackson, and Michael J. Natan, “Ag-Clad Au Nanoparticles: Novel Aggregation, Optical, and Surface-Enhanced Raman Scattering Properties,” J. Phys. Chem., vol. 100, p.p. 718-724, 1996.
[5] David D. Evanoff Jr. and George Chumanov, “Synthesis and Optical Properties of Silver Nanoparticles and Arrays,” ChemPhysChem, vol. 6, p.p 1221-1231, 2005.
[6] Julia fabrega , Shona R. Fawcett , Joanna C . Renshsw, and Jamier. Lead, “Silver Nanoparticle Impact on Bacterial Growth: Effect of pH, Concentration, and Organic Matter,” Environ. Sci. Technol., vol. 43, p.p. 7285–7290, 2009.
[7] Arnim Henglein, “Colloidal Silver Nanoparticles: Photochemical Preparation and Interaction with O2, CCl4, and Some Metal Ions,” Chem. Mater, vol. 10, p.p 444-450, 1998.
[8] Kan-Sen Chou, Chiang-Yuh Ren, “Synthesis of nanosized silver particles by chemical reduction method,” Materials Chemistry and Physic,vol. 64, p.p. 241–246, 2000.
[9] Andrew J Shields, “Review: Semiconductor Quantum Light Sources,” Preprint version of Nature Photonics vol. 1, p.p. 215, 2007.
[10] Kazuhito Hashimoto, Hiroshi Irie and Akira Fujishima, “TiO2 Photocatalysis: A Historical Overview and Future Prospects,” Japanese Journal of Applied Physics vol. 44, No. 12, pp. 8269–8285, 2005.
[11] Akira Fujishima, Tata N. Rao, Donald A. Tryk, “Titanium dioxide photocatalysis,” Journal of Photochemistry and Photobiology C: Photochemistry Reviews vol. 1, p.p. 1–21, 2000.
[12] Kazuya Nakataa, Akira Fujishima “TiO2 photocatalysis: Design and applications,” Journal of Photochemistry and Photobiology C: Photochemistry Reviews vol.13 p.p. 169-189, 2012.
[13] B. Tryba, M. Piszcz and A.W. Morawski, “Photocatalytic and Self-Cleaning Properties of Ag-Doped TiO,” The Open Materials Science Journal, vol. 4, p.p. 5-8, 2010.
[14] Brian O‘Regan, Michael Gratzel, “A low cost, high efficiency solar cell based on dye-sensitized colloidal TiO2 film,” Nature, vol. 353, p.p. 737-740, 1991.
[15] Michele Lazzeri, Andrea Vittadini and Annabella Selloni, “Structure and energetics of stoichiometric TiO2 anatase surfaces,” PHYSICAL REVIEW B, vol. 63, p.p. 155409, 2001.
[16] Agatino Di Paola , Marianna Bellardita and Leonardo Palmisano, “Brookite, the Least Known TiO2 Photocatalyst,” Catalysts, vol. 3, p.p. 36-73, 2013.
[17] B. Montanari, N.M. Harrison, “Lattice dynamics of TiO2 rutile: influence of gradient corrections in density functional calculations,” Chemical Physics Letters vol. 364, p.p. 528–534, 2002.
[18] Marta Mrowetz, William Balcerski, A. J. Colussi, and Michael R. Hoffmann, “Oxidative Power of Nitrogen-Doped TiO2 Photocatalysts under Visible Illumination,” J. Phys. Chem. B, vol. 108, No. 45, p.p. 17269-17273, 2004.
[19] BULENT E. YOLDAS, “Hydrolysis of titanium alkoxide and effects of hydrolytic polycondensation parameters,” JOURNAL OF MATERIALS SCIENCE, vol. 21 p.p. 1087-1092, 1986.
[20] C. Su, B.Y. Hong and C.M. Tseng, “Sol–gel preparation and photocatalysis of titanium dioxide,” Catalysis Today, vol. 96, p.p. 119-126, 2004.
[21] Funda SAYILKAN1, Meltem AS_ILT‥URK2, Hikmet SAYILKAN1_,Yunus ‥ONAL3, Murat Akarsu and Ertu_grul Arpac, “Characterization of TiO2 Synthesized in Alcohol by a Sol-Gel Process: The Effects of Annealing Temperature and Acid Catalyst,” Turk J Chem vol. 29, p.p. 697-706, 2005.
[22] Morten E. Simonsen, Erik G. Sogaard “Sol–gel reactions of titanium alkoxides and water: influence of pH and alkoxy group on cluster formation and properties of the resulting products,” J Sol-Gel Sci Technol , vol. 53, p.p. 485–497, 2010.
[23] GUPTA Shipra Mital, TRIPATHI Manoj, “A review of TiO2 nanoparticles,” Chinese Sci Bull June, vol. 56, No.16, p.p. 1639–1657, 2011.
[24] Chia-Hsin Li, Yung-Hsu Hsieh, Wan-Ting Chiu, Chin-Chuan Liu, Chao-Lang Kao, “Study on preparation and photocatalytic performance of Ag/TiO2 and Pt/TiO2 photocatalysts,” Separation and Purification Technology, vol. 58, p.p. 148–151, 2007.
[25] Sonalika Vaidya, Amitava Patra, Ashok K. Ganguli, “Core–shell nanostructures and nanocomposites of Ag@TiO2: effect of capping agent and shell thickness on the optical properties,” Journal of Nanoparticle Research March, vol. 12, Issue 3, pp 1033-1044, 2010.
[26] Tsutomu Hirakawa, and Prashant V.Kamat, “Charge Separation and Catalytic Activity of Ag@TiO2 Core-Shell Composite Clusters under UV-Irradiation,” J. Am. Chem. Soc, vol. 127 (11), pp 3928–3934, 2005.
[27] Miguel A. Aguilar-Me’ndez , Eduardo San Martı’n-Martı’nez , Lesli Ortega-Arroyo , Georgina Cobia’n-Portillo , Esther Sa’nchez-Espı’ndola, “Synthesis and characterization of silver nanoparticles: effect on phytopathogen Colletotrichum gloesporioides,” J Nanopart Res, vol. 13, p.p. 2525–2532, 2011.
[28] Indrajit Shown, Masaki Ujihara, and Toyoko Imae, “Synthesis of β-Cyclodextrin-Modified Water-Dispersible Ag-TiO2 Core-Shell Nanoparticles and Their Photocatalytic Activity,” Journal of Nanoscience and Nanotechnology, vol. 1, p.p. 1-7, 2011.
[29] L RAMAJO, R PARRA, M REBOREDO and M CASTRO, “Preparation of amine coated silver nanoparticles using triethylenetetramine,” J. Chem. Sci. vol. 121, No. 1, pp. 83–87, 2009.
[30] Hung-Jen Chena, Leeyih Wang, and Wen-Yen Chiu “Chelation and solvent effect on the preparation of titania colloids,” Materials Chemistry and Physics, vol. 101, p.p. 12–19, 2007.
[31] S.Kawata, “Near-Field Optics and Surface Plasmon Polaritons,” Topics Appl. Phys. vol. 81, p.p. 91-122, 2001.
[32] R.W. Miles, K.M. Hynes, I. Forbes, “Photovoltaic solar cells: An overview of state-of-the-art cell development and environmental issues,” Progress in Crystal Growth and Characterization of Materials, vol.51, p.p. 1-42, 2005.
[33] Brian Cook, An introduction to fuel cells and hydrogen technology, Heliocentris 3652 West 5th Avenue Vancouver, BC V6R-1S2 Canada December 2001.
[34] Erik C. Garnett and Peidong Yang, “Silicon Nanowire Radial p-n Junction Solar Cells,” J. AM. CHEM. SOC., vol. 130, p.p. 9224–9225, 2008.
[35] Kohjiro Hara, Takaro Horiguchib, Tohru Kinoshita,Kazuhiro Sayamaa, Hideki Sugiharaa, Hironori Arakawa, “Highly efficient photon-to-electron conversion with mercurochrome-sensitized nanoporous oxide semiconductor solar cells,” Solar Energy Materials & Solar Cells, vol.64, p.p. 115-134, 2000.
[36] Md. K. Nazeeruddin, R. Humphry-Baker, P. Liska, and M. Gra1tzel, “Investigation of Sensitizer Adsorption and the Influence of Protons on Current and Voltage of a Dye-Sensitized Nanocrystalline TiO2 Solar Cell,” J. Phys. Chem. B, vol. 107, p.p. 8981-8987, 2003.
[37] Chaehyeon Lee, Gi-Won Lee, Weekyung Kang, Doh-Kwon Lee, Min Jae Ko, Kyoungkon Kim, and Nam-Gyu Park, “Suppression of Charge Recombination Rate in Nanocrystalline SnO2 by Thin Coatings of Divalent Oxides in Dye-Sensitized Solar Cells,” Bull. Korean Chem. Soc., vol. 31, No. 11,p.p. 3093-3098, 2010.
[38] Julien Preat, Catherine Michaux Denis Jacquemin and Eric A. Perpe`te “Enhanced Efficiency of Organic Dye-Sensitized Solar Cells: Triphenylamine Derivatives,” J. Phys. Chem. C,vol. 113, p.p. 16821–16833, 2009.
[39] Huizhi Zhou, Liqiong Wu, Yuron and Gao, Tingli Ma, “Dye-sensitized solar cells using 20 natural dyes as sensitizers,” Journal of Photochemistry and Photobiology A: Chemistry, vol. 219, p.p. 188-194, 2011.
[40] Amaresh Mishra, Markus K. R. Fischer, and Peter B_uerle, “Metal-Free Organic Dyes for Dye-Sensitized Solar Cells: From Structure: Property Relationships to Design Rules,” Angew. Chem. Int. Ed.vol. 48, p.p. 2474-2499, 2009.
[41] P. M. Sommeling, B. C. O’Regan, R. R. Haswell, H. J. P. Smit, N. J. Bakker, J. J. T. Smits, J. M. Kroon, and J. A. M. van Roosmalen, “Influence of a TiCl4 Post-Treatment on Nanocrystalline TiO2 Films in Dye-Sensitized Solar Cells,” J. Phys. Chem. B, vol. 110, p.p. 19191-19197, 2006.
[42] Gopal K. Mor, Karthik Shankar, Maggie Paulose, Oomman K. Varghese, and Craig A. Grimes, “Use of Highly-Ordered TiO2 Nanotube Arrays in Dye-Sensitized Solar Cells,” Nano Lett., vol. 6, No. 2,p.p. 215-218, 2006.
[43] N.-G. Park, J. van de Lagemaat, and A. J. Frank, “Comparison of Dye-Sensitized Rutile- and Anatase-Based TiO2 Solar Cells,” J. Phys. Chem. B, vol. 104, p.p. 8989-8994, 2000.
[44] Emilio Palomares, John N. Clifford, Saif A. Haque, Thierry Lutza and James R. Durrant, “Slow charge recombination in dye-sensitised solar cells (DSSC) using Al2O3 coated nanoporous TiO2 films,” Chem. Commun., 1464-1465, 2002.
[45] Zhong-Sheng Wang, Hiroshi Kawauchi, Takeo Kashima, Hironori Arakawa, “Significant influence of TiO2 photoelectrode morphology on the energy conversion efficiency of N719 dye-sensitized solar cell,” Coordination Chemistry Reviews, vol. 248, p.p. 1381–1389, 2004.
[46] Kohjiro Hara, Yasufumi Dan-oh, Chiaki Kasada, Yasuyo Ohga, Akira Shinpo, Sadaharu Suga, Kazuhiro Sayama, and Hironori Arakawa. “Effect of Additives on the Photovoltaic Performance of Coumarin-Dye-d NanocrSensitizeystalline TiO2 Solar Cells,” Langmuir, vol. 20, p.p. 4205-4210, 2004.
[47] M. malekshahi byranvand, M. h bazargan, A. nemati kharat “Fabrication and investigation of flexible dye sensitized nanocrystalline solar cell utilizing natural sensitizer operated with gold coated counter electrode,” Digest Journal of Nanomaterials and Biostructures, vol. 5, No 3, p.p. 645-650, 2010.
[48] Yu-Hsiang Hsien, Chi-Fu Chang, Yu-Huang Chen, Soofin Cheng, “Photodegradation of aromatic pollutants in water over TiO2 supported on molecular sieves,” Applied Catalysis B: Environmental, vol. 31, p.p. 241–249, 2001.
[49] Takeshi Morikawa, Ryoji Asahi, Takeshi Ohwaki, Koyu Aoki, Kenichi Suzuki, Yasunori Taga, “Visible light photocatalyst-Nitrogen doped titanium dixode,” R&D review of Toyota CRDL, vol.40 No.3, p.p. 45-50.