Electrodeposition of silver–copper bimetallic particles having two archetypes by facilitated nucleation

We describe two electrochemical methods by which the short-range ordering of two metals (M1 and M2) with respect to one another can be specified during the formation of bimetallic micro- and nanoparticles. These methods are based on the facilitated nucleation of metal M2 by electrodeposited particles of metal M1, as previously described by Deutscher and Fletcher in 1990 (J. Electroanal. Chem. 277 (1990) 1). We demonstrate these strategies using silver for metal M1 and copper for metal M2. Bimetallic core-shell particles having a silver core and a copper shell were obtained by electrodepositing silver particles first, and then electrodepositing copper using a small overpotential. Silver–copper ‘oligomers’, consisting of a central silver particle surrounded by one or more copper ‘satellite’ particles were obtained by first electrodepositing silver particles, assembling an n-alkane thiolate molecular layer on the surfaces of these particles from ethanolic solution, and then electrodepositing copper using a low overpotential. The structures of both types of bimetallic particles was determined using scanning electron microscopy in conjunction with spatially resolved X-ray fluorescence elemental analysis.