Self-Terminating Growth of Platinum Films by Electrochemical Deposition
Yihua Liu (post doc), Dincer Gokcen (post doc), Ugo Bertocci (guest scientist), Carlos Hangarter (post doc), Desiree Garcia (SURF student) and Thomas Moffat (Project leader)
A self-terminating rapid electrodeposition process for controlled growth of platinum (Pt) monolayer films from a K2PtCl4-NaCl electrolyte has been recently developed in our lab. The process is tantamount to wet atomic layer deposition. Despite the deposition overpotential being in excess of 1 volt, Pt deposition was quenched at potentials just negative of proton reduction by an alteration of the double-layer structure induced by a saturated surface coverage of underpotential deposited H (Hupd). The surface was reactivated for further Pt deposition by stepping the potential to more positive values, where Hupd is oxidized and fresh sites for the adsorption of PtCl42– become available. Periodic pulsing of the potential enables sequential deposition of two-dimensional Pt layers to fabricate films of desired thickness, relevant to a range of advanced technologies. In this presentation, I will report on the successful demonstration of this deposition process for growing two-dimensional Pt thin films on both Au and Ni substrates and show the applications of this type of materials in electrocatalysis.