Growth of nickel nanoparticles on an organic self-assembled monolayer template by means of electroless plating

A simple and inexpensive technique to fabricate patterned arrays of monodisperse nickel nanoparticles by the reduction of nickel (II) sulfate with sodium hypophosphite (NaH₂PO₂) using an organic self-assembled monolayer as a template is reported. Monodisperse nickel nanoparticles on self-assembled monolayer (SAMs) templates of 4-(11-mercaptoundecyl)benzene-1,2-diol (MBD) were prepared by a novel strategy based on a modified electroless nickel-plating method. The size of the Ni nanoparticles was readily tuned from 20nm to 400nm, and was dependent on the soaking time and bath conditions during the plating process. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses were performed to demonstrate the successful formation of nickel nanoparticles and to confirm the nanoparticle composition. A complete Ni metal film can be obtained when the substrate was soaked in the Ni elecltroless bath over 4h. Electrical properties of the Au-MBD-Ni were studied via conductive atomic force microscopy (cAFM).