Production of Noble-Metal Nanohelices Based on Nonlinear Dynamics in Electrodeposition of Binary Copper Alloys

Abstract

Spatiotemporal pattern formation is dynamic self-organization widely observed in nature and drives various functions. Among these functions, chirality plays a central role. The relationship between dynamic self-organization and chirality has been an open question; therefore, the production of chiral nanomaterials by dynamic self-organization has not been achieved. Here, we show that the confinement of a two-dimensional spatiotemporal micropattern via the electrodeposition of a binary Cu alloy into a nanopore induces mirror symmetry breaking to produce a helical nanostructure of the noble-metal component although it is still not yet possible to control the handedness at this stage. This result suggests that spatiotemporal symmetry breaking functions as a mirror symmetry breaking if cylindrical pores are given as the boundary condition. This study can be a model system of how spatiotemporal symmetry breaking plays a role in mirror symmetry breaking, and it proposes a new approach to producing helical nanomaterials through dynamic self-organization.

Two-Dimensionally Grown Periodic Pores Formed by Anodization of p-Type Silicon in Concentrated NH4F Aqueous Solution: A Platform for Maskless Patterning of Metals by Electrodeposition

“…In fact, a large number of studies on self-organized materials obtained by anodic dissolution or cathodic electrodeposition of metals, , alloys, , and semiconductors , have been reported. In addition to the wide variety of systems, spatiotemporal patterns obtained in such processes vary from filaments, , dendrites, , nanotrees, multilayers, ,, and spiral waves , to helices. − This variety is why electrochemical systems have attracted attention for the production of materials based on self-organization.…”