Growth of self-organized materials through a photoswitching mechanism

Abstract

This work aims to study the effect of the adsorption of azobenzene molecules on metallic surfaces, preferably on platinum and polycrystalline copper, and from this knowledge, to control the growth of self-organized nanostructures during the oscillatory electrodeposition of Cu/Cu2O by the geometric isomerization of these molecules. The control will be done through the irradiation of light in the ultraviolet and visible region, which induce a selective change in the cis and trans molecular conformation, respectively. This change in the structure of the molecule can result in the variation of the active surface area during the reaction, directly influencing the region of the negative differential resistance. In this way, the electrochemical growth of the deposit will be controlled via a photoswitching mechanism in order to obtain, precisely, a desired thickness or chemical composition of the self-organized material. Initially, the adsorption process will be evaluated by traditional electrochemical experiments such as cyclic voltammetry and chronoamperometry coupled with Fourier Transform Infrared Spectroscopy (FTIR) techniques. With some experimental parameters, we will use the copper oscillatory electrodeposition accompanied by electrochemical quartz crystal microbalance (EQCM) in order to monitor the change in the deposition rate when there is a change in the structural conformation of the azobenzene molecule. Finally, the ellipso-microscopy for superficial imaging (EMSI) will be used to monitor changes in the thickness and refractive index of the formed film. (AU)