[16a-P2-1~18] 12.6 Nanobiotechnology

[16a-P2-18] Electrode size dependence of the characteristics of nanoporous gold formation by anodic dissolution

〇Masiki Ikegami¹, Yu Hirano¹, Yasuhiro Mie¹, Yasuo Komatsu¹ (1.AIST)

Keywords:nanostructure, electrode, nanoporous gold

We developed a novel one-step fabrication method of nanoporous gold (NPG) on the electrode by anodic dissolution of the gold electrode in the low concentration of hydrochloric acid. Anodization voltage to enable fabrication of NPG is critical for the anodization condition. In this presentation, we have tested three anodization condition; microelectrode in 25 mM HCl, microelectrode in 35 mM HCl and macro electrode in 25 mM HCl. These three condition provided NPG on the surface of the electrode. We have measured the successive anodization voltage which enables formation of NPG. In case of microelectrode in 25 mM HCl, increase of the surface area of the electrode by NPG was biggest at 1.215 mV and half width was 3.5 mV. In case of the macro electrode in 25 mM HCl, half width was 12.5 mV, that was much bigger than that of the microelectrode. The mass transport of the electroactive species is linear diffusion normal to the electrode surface in the macro electrode, on the other hand, it is three dimensional diffusion in the microelectrode, resulting the difference of the diffusion rate near the electrode surface. This is the reason for the difference of the half width of the two electrodes.