Complete reconfiguration of dendritic gold.

The present work extends the directed electrochemical nanowire assembly (DENA) methodology, which is a technique for growing single crystalline metallic nanowires and nano-dendrites from simple salt solutions, to enable the complete dissolution of the metallic dendrites following their growth. The experimental parameters that control this process are the frequency and the duty cycle of the alternating voltage signal that initiates electrochemical dendritic growth. Cyclic voltammetric and Raman measurements imply that the reconfiguration of dendritic gold occurs by way of the same interfacial reduction and oxidation mechanisms as bulk gold. We present a model that illustrates how the experimental parameters (frequency and duty cycle) induce reconfiguration by controlling the rates at which reduction, oxidation, and Au(III)Cl4(-) diffusion take place. This capability is significant because in making dendritic solidification a reconfigurable process, we have established an innovative means of applying fully reconfigurable metallic nano-structures to substrates; in turn, this capability could potentially enable the smart modulation of the adhesive, anti-corrosive, or optical properties of the substrate.