Kinetic studies of underpotential deposition of antimony on Se-modified Au electrode

Atomic layers of antimony can be electrodeposited onto the Se monolayer covered Au electrode in the underpotential region. In this paper, the formation and dissolution kinetics of antimony monolayer on the Se monolayer covered Au electrode are investigated using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. Scanning-rate-dependent CV experiments reveal that the peak current of underpotential deposition (UPD) wave of antimony is not a linear function of the scanning rate, υ, but scales as υ ^2/3. Similar behavior is observed when the Antimony monolayer is stripped from the modified substrate. These results indicate the character of monolayer formation and dissolution by a two-dimensional nucleation and growth mechanism. Additionally, current density−time transient obtained through CA experiments also reveal that both the deposition and stripping of the antimony monolayer involve an instantaneous nucleation and two-dimensional growth process.