Synthesis and characterization of Au/TiO2 core-shell structure nanoparticles

Au/TiO2 core-shell structure nanoparticles were synthesized by sol-gel process, and the morphology and crystallinity of TiO2 shell were investigated by TEM and UV-vis absorption spectrometer. Au/TiO2 Core-shell structure nanoparticles could be prepared by the hydrolysis of TOAA (titanium oxide acethylacetonate) in gold sol ethanol solution with water. The thickness of TiO2 shell on the surface of gold particles was about 1 nm. To investigate the crystallinity of TiO2 shell, LJV light with 254 nm and radioactive ray of Co-60 were irradiated on the TiO2-coated gold sol ethanol solution. The surface plasmon band of gold nanoparticles appeared only when the radioactive ray was irradiated on the TiO2-coated gold sol ethanol solution. From these results, it was found that the TiO2 shell was amorphous and the MUA (mercaptoundecanoic acid) layer on the Au particle for its dispersion in ethanol did not act as an obstacle to disturb the movement of electrons onto the surface of Au particles.