title: Surface functionalization of electro-deposited nickel.
abstract: A new in situ electrochemical method of functionalizing an oxide-free Ni surface is demonstrated using octanethiol. Initial adsorption results in a multilayer molecular film, which blocks both the hydrogen evolution reaction (HER) and re-oxidation of the Ni by ambient oxygen. However, excess octanethiol can be removed by rinsing with ethanol, leaving behind a monolayer that continues to protect against re-oxidation but gives rise to an unexpected enhancement in the HER, with a greater enhancement for longer film formation times. The presence of an octanethiol monolayer on the surface was confirmed by spectroscopic observation of the CH(2), CH(3) and thiolate groups using infra red spectroscopy, while X-ray photo-electron spectroscopy demonstrated the effectiveness of the thiol layer as a barrier to surface oxidation. The electrochemically prepared octanethiol film impedes oxidation of the Ni in air more effectively than a film formed by immersion in a solution of octanethiol in ethanol.
authors.affiliation: HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL.
authors.forename: James E
authors.initials: JE
authors.lastname: Sadler
authors.forename: Doug S
authors.initials: DS
authors.lastname: Szumski
authors.forename: Agnieska
authors.initials: A
authors.lastname: Kierzkowska
authors.forename: Samantha R
authors.initials: SR
authors.lastname: Catarelli
authors.forename: Kevin
authors.initials: K
authors.lastname: Stella
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Nichols
authors.forename: Mariano H
authors.initials: MH
authors.lastname: Fonticelli
authors.forename: Guillermo
authors.initials: G
authors.lastname: Benitez
authors.forename: Bárbara
authors.initials: B
authors.lastname: Blum
authors.forename: Roberto C
authors.initials: RC
authors.lastname: Salvarezza
authors.forename: Walther
authors.initials: W
authors.lastname: Schwarzacher