Underpotential Deposition of Tl on (111)-Textured Au: In Situ Stress and Nanogravimetric Measurements

Published

September 15, 2010

Author(s)

Jae W. Shin, Ugo Bertocci, Gery R. Stafford

Abstract

The surface stress associated with the underpotential deposition (UPD) of thallium (Tl) on (111)-textured Au is examined, using the wafer curvature method, in acidic perchlorate supporting electrolyte. The process was also examined by independent nanogravimetric measurements using an electrochemical quartz crystal nanobalance (EQNB). We observe a sweep rate dependence for both the individual voltammetric waves and stress response which we attribute to kinetically controlled surface alloying which occurs only at low coverage. Similar behavior has been reported for Pb UPD on (111)-textured Au but the kinetics for Tl are considerably slower and are very sensitive to the defect density of the Au(111) surface. At high coverage, a hexagonal close packed (hcp) Tl monolayer is formed while the surface alloy is removed. The stress hump that is coincident with the last voltammetric wave appears to be caused by the formation and removal of the surface alloy. This is confirmed by long-term potentiostatic pulsing experiments.

Citation

Journal of Physical Chemistry C

Pub Type

Journals

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DOI Link

Keywords

(111)-textured Au, perchloric acid, stress relaxation, surface alloying, surface stress, underpotnetial deposition, voltammetry

Citation

Shin, J. , Bertocci, U. and Stafford, G. (2010), Underpotential Deposition of Tl on (111)-Textured Au: In Situ Stress and Nanogravimetric Measurements, Journal of Physical Chemistry C, [online], https://doi.org/10.1021/jp1034486 (Accessed December 15, 2024)