具非等向性結構之鈀奈米晶體作為甲酸氧化之電化學觸媒研究

Abstract

在此論文，我們成功利用一存在PVP水溶液的系統，以化學還原法合成出不同形狀的鈀奈米晶體，包括奈米板狀，八面體，孔狀和中空狀。我們使用PdCl2 當前驅物而PVP扮演還原劑和穩定劑，另外我們加入一些特定的鹽類如NaCl和NH4OH。在此合成系統中，鈀奈米晶體之形貌與尺寸可藉由相關反應條件之操控來調整，例如PdCl2和鹽類的莫耳數和反應溫度。我們將四種不同鈀奈米型狀應用電化學活性中的甲酸氧化和氫氣的吸脫附，我們可以發現不同的形狀在甲酸氧化有不同的現象。非等向結性構的鈀奈米晶體亦應用在表面增強拉曼，由於鈀奈米形狀不同影響有機分子在拉曼的靈敏度。

In this thesis, we successfully synthesized various palladium (Pd) nanocrystals including nanoplates, octahedrons, porous nanocrystals, and hollow nanocrystals in the PVP-assisted chemical reduction process. The synthesis involved only the use of PdCl2 as the precursor, PVP as the reducing and stabilizing agents, and a specific salt like NaCl or NH4OH as the additive. By modulating the relevant reaction conditions such as the amount of PdCl2, the amount of additive, and the reaction temperature, we were able to obtain Pd nanocrystals with controllable morphologies. The four types of Pd nanocrystals exhibited notable electrocatalytic activities toward formic acid oxidation and hydrogen adsorption/desorption. Surface-enhanced Raman spectroscopy for the anisotropically-shaped Pd of nanoplates and octahedrons was also investigated to demonstrate their potential as an active substrate for Raman-sensitive analyte molecules.