Producción CyT
Congreso
Autoría
M. C. Giménez
;
Oscar A. Oviedo
;
Ezequiel P. M. Leiva
Fecha
2024
Editorial y Lugar de Edición
Centro atómico Bariloche
Resumen
Información suministrada por el agente en
SIGEVA
Background: The galvanic replacement of a previously adsorbed Cu monolayer by underpotential deposition on an Au(111) surface by Pt atoms has been studied experimentally in the literature. It was found that for every 4 Cu atoms that leave, one Pt atom enters. Therefore, from an initial coverage degree $heta_{Cu} =1$, a final coverage $heta_{Pt} = 0.25$ is obtained. Eventually the Pt adatoms diffuse over the surface, leading to the formation of islands of this metal on the surface.In the present...
Background: The galvanic replacement of a previously adsorbed Cu monolayer by underpotential deposition on an Au(111) surface by Pt atoms has been studied experimentally in the literature. It was found that for every 4 Cu atoms that leave, one Pt atom enters. Therefore, from an initial coverage degree $heta_{Cu} =1$, a final coverage $heta_{Pt} = 0.25$ is obtained. Eventually the Pt adatoms diffuse over the surface, leading to the formation of islands of this metal on the surface.In the present work, the diffusion-coupled electrodeposition of Pt atoms on Au(111) surfaces was simulated by kinetic Monte Carlo to study the electrochemical deposition and the spontaneous formation of platinum islands on gold. On the one hand, the diffusion rates were calculated using the absolute rate theory, with some parameters based on EAM calculations. On the other hand, the deposition rates $v_{dep}$ were considered parametrically taking several possible values (emulating different experimental conditions).This scheme allowed access to the temporal evolution and final states of the islands, compatible with the degree of coverage $heta_{Pt} = 0.25$, and the effect of $v_{dep}$. In all cases, the morphology of the deposited islands was found to be rather branched, rather than compact islands. The distribution of island sizes in the final state is broader and tends to higher values for lower values of $v_{dep}$.
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Palabras Clave
Kinetic Monte CarlodepositiongoldPlatinum