Kazuhiro Fukami

Mechanisms for potential oscillations and synchronizing self-organized formation of ordered dendrite structures, which is an important example of morphogenesis in Laplacian fields, were studied using Sn, Zn, Cu, and Pb electrodeposition. Electron backscattering diffraction (EBSD) experiments showed that Sn latticework as a typical example of the ordered dendrite structures grew in an epitaxial mode in particular directions from the Sn electrode surface. In situ optical and phase-contrast microsc

The electrodeposition of noble metals, i.e., platinum, palladium, and gold, into macroporous p-type silicon was examined. For platinum and palladium, the electrodeposition proceeded preferentially from the pore bottom to the opening when sodium chloride was used as a supporting electrolyte. When sodium sulfate was used as a supporting electrolyte, the electrodeposition mainly proceeded at pore openings, leading to plugging. For gold electrodeposition, a condition for achieving pore filling from

Electrodeposition of gold into porous silicon was investigated. In the present study, porous silicon with ~100 nm in pore diameter, so-called medium-sized pores, was used as template electrode for gold electrodeposition. The growth behavior of gold deposits was studied by scanning electron microscope observation of the gold deposited porous silicon. Gold nanorod arrays with different rod lengths were prepared, and their surface-enhanced Raman scattering properties were investigated. We found tha

Electrodeposition of zinc (Zn) from a strongly alkaline Zn(II) solution showed a potential oscillation in the region of the current density exceeding the diffusion-limited one, accompanied by the formation of dendrites with a stacked wafer structure. Scanning electron microscopic inspection showed that the dendrites changed their shape periodically in synchronization with the potential oscillation from thick hexagonal wafers on the negative potential side to thin maple-leaf-like wafers on the po

Nanometric chiral objects such as twisted or helical nanoribbons represent a new class of objects having important potential in a large panel of applications, taking advantage, for example, of electromechanical or optical chirality, local chiral environment for catalysis, and chiral recognition. Supramolecular chemistry has played a central role in the production of such structures through either chiral macromolecules/foldamers or the self-assembly of chiral molecules; the latter can also be use

A medium-entropy alloy (MEA) of CoNiCu with a face-centered cubic structure was successfully obtained by electrochemical deposition. To achieve a nearly equiatomic composition, a water-in-oil emulsion was used as the solution for electrodeposition. Since the water droplets in the emulsion tended to be destroyed within 10 min under electrolysis, the emulsion was periodically irradiated ultrasonically to maintain its emulsified state in order to obtain a continuous film by electrodeposition. Chara

An electrochemical reaction within nanopores is remarkably decelerated once a diffusion-limited condition is reached due to the difficulty in supply of reactants from the bulk. Here, we report a powerful method of overcoming this problem for electrochemical deposition of platinum within nanopores formed on silicon. We made the pore wall surface of the silicon electrode hydrophobic by covering it with organic molecules and adopted platinum complex ions with sufficiently large sizes. Such ions, wh