Photochemical synthesis of Au nanostructures : catalyzed by titanium dioxide

• Main Author: Sun, Juan.
• Other Authors: Zhang Hua
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/39990
• Institution: Nanyang Technological University

A facile method was developed to synthesize controlled anisotropic Au nanocrystals by photo-irradiating a solution containing HAuCl4 and TiO2 sols in ethanol without the addition of any other surface capping molecules. TiO2 acted as the photo catalyst and together with the controlled addition of AgNO3, different morphologies of Au nanostructures have been synthesized. A mechanism for the reduction of Au3+ to Au0, and the growth formation of nanoparticles was hypothesized, with the aid of scanning electron microscope (SEM) and transmission electron microscope (TEM), to characterize the morphological changes with the amount of HAuCl4 and reaction time. UV-Vis spectroscopy was also carried out to explain the changes in color for the solution at different steps of the process. With the optimization of experimental parameters, the size, shape and distribution of the Au nanoparticles can be controlled.