Fabrication of gold nano particle layer without support material

Takahashi, Ayaka*; Sugawara, Toshifumi*; Shimada, Akihiko; Hakoda, Teruyuki; Sugimoto, Masaki; Aritani, Hirofumi*; Yoshikawa, Masahito

Recently, it is appeared that gold nano particles have catalytic activity of CO oxidation, though bulk gold does not have. The representative method to fabricate catalyst, impregnation, is rather complex method. This method is divided into sink, evaporation with mixing, drying, high temperature baking. If gold nano particle layer is fabricated, gold nano particle catalyst is fabricated only transferring to catalyst support material. Thus, we try to fabricate gold nano particle layer by electron beam irradiation from tetrachloroauric (3) acid solution, by radiation reduction method. One mmol/L tetrachloroauric (3) acid solution including 0.5 - 20% of ethanol was irradiated by electron beam (55 keV). Red, thin film-like-float (layer) is generated. This layer is measured by TEM and XPS. It is appeared that about 5 nm of nano particle (supposed to gold) is existed and most of the gold in the layer is zero valence (metallic) gold. So we show that gold nano particle layer is fabricated from tetrachloroauric (3) acid solution by radiation reduction method.