Production of Au nanoparticle films using electron-beam induced non-thermal plasma on the surface of aqueous solutions

Hakoda, Teruyuki; Takahashi, Ayaka*; Shimada, Akihiko; Yamamoto, Shunya; Aritani, Hirofumi*; Yamaki, Tetsuya

Aqueous solutions containing 1 mmol/L AuCl ions and 0.5-20v% alcohol (2-propanol or ethanol) were irradiated with a few tens keV electron beams (EBs). Gold (Au) films were produced on the surface of the irradiated solution. The production rate of the Au films was high at concentrations of 0.5-1v% for 2-propanol and became lower at higher concentrations. At an alcohol concentration of 0.5v%, the Au particles of the films were 5-20 nm and 5-100 nm in diameter for 2-propanol and ethanol, respectively. The XPS analysis demonstrated that the films consisted of about 85wt% of metal Au(0), 10wt% of Au(I), and a few wt% of Au(III) for 2-propanol. A Fourier transform infrared diffusion reflectance (FTIR-DR) measurement showed that CO was oxidized into CO over the Au films loaded to TiO substrates at a temperature of 200C, enabling us to confirm a catalytic activity.