The formation of an atomically thin, Ag layer on a Au(111) surface has been shown to significantly alter the thermal properties of the underlying substrate (1). A further exploration into the chemical mechanisms by which these thin films are deposited reveals two different sources of Ag during the formation of the monolayer via AgCl or AgBr. Electrochemical Scanning Tunneling Microscopy (EC-STM) and Cyclic Voltammetry (CV) are used to probe the in-situ interfaces of these metal systems. EC-STM is a unique technique that, in addition to providing a local probe of the atomic surface structure, also functions as a 3-electrode cell in which redox chemistry can be performed to understand the chemical reactivity of the surface. Also, cyclic voltammograms (CVs) can be generated to provide specific information regarding the nature of the redox events occurring at the surface. The two sources of silver used for the Underpotential Deposition (UPD) process on Au(111) result in significantly different thermal stabilities of the surface. The ability to experimentally choose different surface properties based on electrochemical parameters and solution composition during metal deposition could lead to exciting new directions for thin film technologies. These findings have been recently published in a journal article in Surface Science (2). Future projects include examining the stability of AgI, soluble Ag salts, and using XPS and DFT experiments to further probe the surface chemistry of these unique layers.
(1) Iski et al. Electrochimica Acta (2011), 56, 1652-1661.
(2) Phillips et al. Surface Science (2018), doi.org/10.1016/j.susc.2018.08.006.