Electrodeposition the versatile technique for nanomaterials

Abstract Electrodeposition is a weU-known conventional surface modification method to improve the surface characteristics, decorative and functional, of a wide variety of materials. Now, electrodeposition is emerging as an accepted versatile technique for the preparation of nanomaterials. Work done in this direction is discussed in this chapter. The basics of electrodeposition are introduced, then the electrodeposition of nanomaterials using special techniques for reducing grain size. Methods such as pulse and pulse reverse current deposition, template-assisted deposition and use of additives and grain refiners are explained with suitable examples. Deposition of nanostructured metals, alloys, metal matrix composites, multilayers and biocompatible materials reported in the literature are discussed. Finally, there is a discussion of the improved corrosion resistance of electrodeposited nanostructured materials, quoting results reported in Uterature. 

Key words electrodeposition, nanomaterials, pulse and pulse reverse electrodeposition, template-assisted deposition, additives and grain refiners, nanostuctured metals and alloys, nanocomposites, multilayers, biocompatible materials, corrosion resistance of electrodeposited nanostuctured materials. 

An electrolysis cell circuit consists of an anode (the positive electrode), a cathode (the negative electrode), an electrolytic bath, a current source and an ampere/volt 

In simple salt solutions, metal ions are present in bulk solution as hydrated ions the metal ion when hydrated is represented as M(H20)/, where x is the number of water molecules in the primary hydration sheath. The reactions involved in the discharge process (Raub and Muller, 1967) of ions under the influence of an electric field are the transport of hydrated ions towards the cathode surface, the alignment of water molecules in the diffusion layer, the removal of water molecules in the Helmholtz layer, discharge followed by adsorption of the ions at the cathode surface as adatoms , surface diffusion and the incorporation of adatoms into the crystal lattice at the growth point. A schematic representation of these steps is given in Fig. 5.1. 

1 Schematic representation of steps in the cathodic deposition of metals. 

---