以金屬奈米結構增益表面電漿光觸媒於水解反應之研究

Metallic Nanostructure for Plasmon-Enhanced Photocatalytic Water Splitting

鍾光聖(Kuang-Sheng Chung)

指導教授 ： 蔡定平

國立臺灣大學/理學院/物理研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10875

摘要

本研究擬探討在金屬結構尺度小於入射電磁波波長時，所展現出的表面電漿共振(surface plasmon resonance, SPR)特性於光觸媒材料上的應用。表面電漿(surface plasmon)是金屬內自由電子受電磁波激發後的集體震盪，若與光子耦合沿金屬表面傳播即形成表面電漿極化子(surface plasmon-polaritons, SPPs)，若為金屬奈米粒子則形成侷域化表面電漿共振(localized surface plasmon resonance, LSPR)。因表面電漿共振時具有將入射光轉為奈米尺度下集中電磁場的性質，在應用上被部份光伏材料(photovoltaics materials)研究學者視為增益效率的方法之一。本論文以此概念為出發，使用二氧化鈦(Titanium dioxide)為光伏材料，結合銀粒子�隔層�金膜的多層膜結構與大面積金屬奈米溝軌，並量測其光觸媒效益作為驗證，分別探討近年來爭議不斷的奈米結構增強光伏效率的說法，與提出耦合增益光觸媒表現的新結構。

關鍵字

表面電漿共振 ； 光伏材料 ； 奈米金屬粒子 ； 奈米結構 ； 光觸媒 ； 二氧化鈦

並列摘要

This essay is based on the phenomenon about surface plasmon resonance (SPR), which happens to free electron in nanostructured metal when irradiated EM wave, and its application in enhancing photocatalysis material, Titanium dioxide. Surface plasmon is the behavior of collective electron oscillation at the metal/dielectric interface, and if surface plasmon couple with incident photon, it becomes surface plasmon polaritons (SPPs) and would propagate along the surface; the other case is localized surface plasmon resonance (LSPR), which usually excited by light in metallic nanoparticles, and both of SPPs and LSPR would have novel properties such as turning the incident light into near field intensive EM wave. Thus, surface plasmon is regarded as one of the new approaches to enhance photovoltaics materials by some scholars. Starting from this point, here we combine Titanium dioxide and nanostructured metal, Ag nanoparticles/spacer/Au thin film, and self-developed method to fabricate large grating Au film, to test the idea of plasmonic photovoltaics devices. By measuring the photocatalysis performance, the controversial idea and debates about the mechanism is much more clarified, and a new structure to enhance photovoltaics material by the coupling of surface plasmon is proposed in this essay, separately.

並列關鍵字

surface plasmon resonance ； photovoltaics materials ； metallic nanoparticles ； nanostructure ； photocatalysis ； Titanium dioxide

參考文獻

[1] D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Physical Review Letters 84, 4184–7 (2000).

[2] W. A. Tisdale, K. J. Williams, B. A. Timp, D. J. Norris, E. S. Aydil, X.-Y. Zhu, “Hot-electron transfer from semiconductor nanocrystals,” Science 328, 1543 (2010).

[3] N. Fang, H. Lee, C. Sun, X. Zhang, “Sub–diffraction-limited optical imaging with a silver superlens,” Science 308, 534–537 (2005).

[4] T. M. Razykov, C. S. Ferekides, D. Morel, E. Stefanakos, H. S. Ullal, H. M. Upadhyaya, “Photovoltaic manufacturing: Present status, future prospects, and research needs,” Solar Energy 85, 1580–1608 (2011).

[5] B. O'Regan, M. Gratzel, “A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films,” Nature 353, 737 (1991).