Surface plasmon resonance is a photophysical phenomenon, which attracts broad interest with possible applications in sensing, nanolasers and electrochemical reaction catalysis. Meanwhile, gold nanoparticles are excellent candidates among all plasmonic noble metals, showing good and controllable plasmonic features. The aim of this thesis is to study the unique optical properties of gold nanoparticles and gold composites and demonstrate the energy transfer in plasmon enhanced fluorescence, SPASER and oxygen evolution reaction (OER) catalysis via microscopic and spectroscopic techniques.Firstly, synthesis of colloid gold nanoparticles was introduced in Chapter 3. Surface modifications of gold with silica and polymers were also discussed in this part as well as 2D MnO2 nanosheets fabrication. In addition, the function of each reaction regents was also explained as well as the development background of each synthetic method.Then in Chapter 4, the surface plasmon effect on the energy transfer towards SPASER was investigated with a Rh 800 doped polystyrene-gold nanorod core-shell structure. The steady state and time-resolved fluorescence spectroscopy study disclosed an enhanced energy transfer when the longitudinal surface plasmon mode of the gold nanorods overlapped with the absorption and emission of Rh 800.Further study was performed on the metal enhanced fluorescence employing Mega 520 dye loaded mesoporous silica coated gold nanorods in Chapter 5. Fluorescence enhancement was found arising from both increased excitation rate as the transverse surface plasmon mode of gold nanorods overlapped with the excitation wavelength and enhanced quantum yield when the emission of the dye was not coincident with the longitudinal plasmon mode. Furthermore, this study revealed the distance dependence of the enhancement effect.Finally in Chapter 6, a gold-MnO2 catalyst was designed and prepared with excellent OER catalytic performance. It is believed that the plasmon-induced Mnn+ species provide active sites to extract electrons from OH- to facilitate the oxygen evolution. By tuning the laser intensity from 100 to 200 mW, the overpotential was decreased from 0.38 to 0.32 V, which was comparable to IrO2 and RuO2 catalysts.
|Date of Award||4 Dec 2018|
- University Of Strathclyde
|Supervisor||Yu Chen (Supervisor) & David Birch (Supervisor)|