Decomposition of Monolayer Coverage on Gold Nanoparticles by UV/ozone Treatment

Abstract

Au nanoparticles, covered with cationic dichain surfactant on the whole surface, were treated with UV/ozone. FT-IR spectra of the Au nanoparticles with bottom-, upper-, and fully covered surfactant monolayers revealed a variable decomposition rate. The sum frequency generation spectra of the treated nanoparticles showed that the surface coverage of gold nanoparticles lose the centrosymmetric structure, implying asymmetric distribution of the protected surfactant molecules. The UV–vis electronic absorption spectra suggested stable nanoparticle monolayer film structure after UV/ozone irradiation.