Formation of a nickel hydroxide monolayer on Au through a self-assembled monolayer of 5,5 '-dithiobis(2-nitrobenzoic acid): voltammetric, SERS and XPS investigations of the modified electrodes

The formation of self-assembled monolayers (SAM) of 5,5'-dithiobis (2-nitro benzoic acid), DNBA on gold has enabled further derivatization of the elect rode surface with functional moieties anchored to the surface bound molecul es. A SAM of DNBA was formed on the Au surface. Nickel ions tethered to the SAM-covered Au surface, were subsequently derivatized electrochemically to yield nickel hydroxide overlayers, thereby showing the possibility of prep aring ultra-thin films of metal oxides through solution chemistry. The nick el hydroxide surface coverage obtained on bare and SAM-covered electrodes w as estimated from voltammetric peaks and it varied from one monolayer to ab out 300 monolayers. The formation of a monolayer of nickel hydroxide has be en achieved for the first time by electrochemical modification. Further, th e modified electrodes were subjected to SERS and XPS studies to understand their surface characteristics. Modified electrodes provide a catalytic path way involving nickel hydroxide for the electro-oxidation of glucose in alka line solutions. (C) 1999 Elsevier Science S.A. All rights reserved.