Coordination-controlled electrodeposition of palladium/copper thin films onto a pyridine-terminated self-assembled monolayer
Abstract
A scheme for the electrodeposition of ultrathin bimetallic layers on top of a self-assembled monolayer (SAM) is investigated which combines the deposition of one metal (Pd) coordinated to a functionalized SAM (3-(4-pyridine-4-yl-phenyl)-propane-1-thiol, PyP3) on Au/mica with another metal (Cu) from the bulk electrolyte. The coordination-controlled electrodeposition (CCED) is a four-phase process comprising (i) Pd2+ coordination to the terminal pyridine units of the SAM, (ii) reduction of Pd and nanoparticle formation, (iii) formation of an intermixed shell of Pd and Cu, and (iv) deposition of bulk Cu. Chronoamperometry reveals a fast nucleation phase where Pd nanoparticles form within a few milliseconds and seed the Cu deposition. The Pd-Cu core-shell nature of deposited nanoparticles is confirmed by transmission electron microscopy (TEM). Harnessing the selective coordination of Pd2+ to PyP3, a one-pot procedure is further developed using electrolytes containing both Pd2+ and Cu2+ ions. Thus simplifying complexation and reduction, continuous Pd/Cu films are obtained in a multistep process as verified by scanning tunneling microscopy (STM). With a percolation threshold below 3 nm, CCED, as a SAM-controlled deposition strategy, offers an avenue for generation of ultrathin films.
Citation
Yao , Z , Naden , A B , Baker , R T & Buck , M 2022 , ' Coordination-controlled electrodeposition of palladium/copper thin films onto a pyridine-terminated self-assembled monolayer ' , Journal of The Electrochemical Society , vol. 169 , no. 11 , 112515 . https://doi.org/10.1149/1945-7111/aca17e
Publication
Journal of The Electrochemical Society
Status
Peer reviewed
ISSN
1945-7111Type
Journal article
Description
Funding: Support by the Chinese Scholarship Council and the University of St Andrews for a stipend (Z. Y.) are gratefully acknowledged. Electron microscopy was carried out at the Electron Microscopy Facility, School of Chemistry, University of St Andrews and we acknowledge recent funding for the Facility from the EPSRC (EP/T019298/1, EP/L017008/1) and the EPSRC Strategic Resources Grant (EP/R023751/1).Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.