Fabrication of gold/polyvinyl-alcohol nano-composites by photoreduction and their optical characterization

The photoreduction process in a gold-polyvinyl alcohol film is studied. Upon irradiation with UV light, photoreduction takes place to reduce gold, resulting in a nano-composite film. As time elapses, gold nano-particles are formed inside the polymer matrix. The optical absorption spectra confirms the presence of a surface plasmon resonance, which is attributed to the gold nano-particles. The changes in the surface plasmon resonance peak are investigated as the preparation parameters, such as the irradiation time, the film thickness, and the molecular weight of polyvinyl alcohol polymer, are varied. Furthermore, energy dispersive spectroscopy was employed to quantitatively identify the amount of photoreduction in the gold-polyvinyl alcohol film.