銀奈米粒子催化甲基藍降解之表面增強拉曼散射光譜研究

Surface-enhanced Raman Scattering Studies of the Degradation of Methylene Blue Catalyzed by Silver Nanoparticles

李志峻(Chih-Chun Li)

指導教授 ： 黃俊嬴

高雄醫學大學/生命科學院/醫藥暨應用化學系碩士班/碩士(2017年)

摘要

表面增強拉曼光譜（SERS）是一項發展十分健全、擁有高敏感度的分析技術，SERS具有獨特的光譜指紋區和化學環境資訊等優點，使其成為近年來發展最迅速的分析技術之一。電磁效應和化學增強是SERS的兩項主要機制，而其中電磁效應跟拉曼增強的現象尤為相關，也因為此原因，在粗糙的貴金屬或奈米級的貴金屬粒子（銀、金、銅等等）上吸附離子或分子來偵測分析其分子結構性質，近年引起廣泛的興趣與討論，並有越來越多的人投入研究。
在本篇研究中，銀奈米粒子（AgNPs）被應用作為催化劑，用以催化NaBH4 對有機染料的降解反應，SERS則被用以監控反應過程中銀奈米粒子表面的拉曼訊號增強效果。紫外線-可見光光譜用以追蹤樣品溶液中反應物與產物在不同濃度下的光譜變化結果，從而得知以比較樣本溶液中不同體積的銀奈米粒子的催化效果。從結果發現，樣本溶液中的UV-Vis吸收值隨著反應時間的進行而逐漸削減衰退，同時在銀奈米粒子表面偵測的SERS光譜也出現變化，藉由觀察並解析UV-Vis和SERS的光譜可以對銀奈米粒子的催化有新的認識，也對銀奈米粒子所扮演的角色有進一步的了解。

關鍵字

甲基藍 ； 表面增強拉曼光譜 ； 催化 ； 降解 ； 銀奈米粒子

並列摘要

Surface-enhanced Raman scattering (SERS) spectroscopy is a well-established and highly sensitive technique with the advantage of unique spectroscopic fingerprint and abundant chemical environmental information. Electromagnetic and chemical enhancement are two mechanisms accounting for the SERS effect. Between the two mechanisms mentioned above, electromagnetic effect is mainly responsible for the Raman signal enhancement. For this reason, the detecting ionic and molecular species adsorbed on roughened noble metal or nano-sized noble metal particles, such as Ag, Au, Cu, etc. has been given more and more attention and research interests.
In this study, silver nanoparticles (AgNPs) were applied as the nano catalysts for the degradation of organic dyes in the presence of sodium borohydride (NaBH4). SERS was used to monitor the surfaces of AgNPs during the reaction. Meanwhile, UV–Vis spectrometry was used to trace the concentration variations of reactants and products in bulk solutions, thereby correlating the variations of the Ag nanocatalyst surfaces with those in the bulk solutions. The results indicated that the absorbance of dye molecules in the bulk solution reduced as the reaction proceeded. Simultaneously, the variations of SERS spectra on AgNPs surfaces were also observed. Analyzing the collected SERS and UV–Vis spectra can provide a new insight into Ag nanoparticle catalysis, and the role of Ag nanocatalysts can be further comprehended.

並列關鍵字

SERS ； Raman ； methylene blue ； catalyze ； degradation ； silver nanoparticles

參考文獻

(1) Pope, I.; Payne, L.; Zoriniants, G.; Thomas, E.; Williams, O.; Watson, P.; Langbein, W.; Borri, P. Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds. Nature Nanotechnology 2014, 9, 940-946.

(2) Raman, C. V.; Krishnan, K. S. Molecular Spectra in the Extreme Infra-Red. Nature 1928, 122, 278-278.

(3) Albrecht, M. G.; Creighton, J. A. Anomalously intense Raman spectra of pyridine at a silver electrode. Journal of the American Chemical Society 1977, 99, 5215-5217.

(4) Fleischmann, M.; Hendra, P. J.; McQuillan, A. J. Raman spectra of pyridine adsorbed at a silver electrode. Chemical Physics Letters 1974, 26, 163-166.

(5) Huang, J.; Chen, F.; Zhang, Q.; Zhan, Y.; Ma, D.; Xu, K.; Zhao, Y. 3D silver nanoparticles decorated zinc oxide/silicon heterostructured nanomace arrays as high-performance surface-enhanced Raman scattering substrates. ACS Applied materials & interfaces 2015, 7, 5725-5735.