Nanomaterials, synthesis electrodeposition

Common methods for the fabrication of metallic nanoparticle arrays are electron beam lithography, photolithography, laser ablation, colloidal synthesis, electrodeposition and, in recent time, nanosphere lithography for which a monodisperse nanosphere template acts as deposition mask. A review on advances in preparation of nanomaterials with localized plasmon resonance is given in [15]. 

Usually there is a lot of effort required to make nanomaterials by electrochemical means. In aqueous solutions the electrodeposition of nanocrystalline metals requires pulsed electrodeposition and the addition of additives whose reaction mechanism hitherto has only been partly understood (see Chapter 8). A further shortcoming is that usually a compact bulk material is obtained instead of isolated particles. The chemical synthesis of metal or metal oxide nanoparticles in aqueous or organic solutions by colloidal chemistry, for example, also requires additives and often the desired product is only obtained under quite limited chemical conditions. Changing one parameter can lead to a different product. 

In spite of the exquisite control of reaction rate and duration afforded by electrochemical methods, electrodeposition has hardly been used for preparing nanomaterials. An exception to this generalization is the synthesis of nanoparticles and nanorods using the template synthesis method pioneered by Martin (1-6), Moskovits and co-workers (7-9), and Searson and co-workers (10-16). Template synthesis (Scheme 16.1.1) involves the electrodeposition of materials into the pores of ultrafiltration membranes (e.g., Nuclepore and Anopore ) that have uniform, cylindrical, or prismatic pores of a particular size. 

Similarly, ionic liquids are finding increasing use in the popular area of nanomaterials. Much of this effort is directed toward using ionic liquids as either solvents for the synthesis of nanomaterials (Nan and Liebscher) or their stabilization (Kraynov and Mueller). Electrodeposition and recovery of metals is a related and fairly mature field (Anicai, Florea, and Visan). 

A BCP is a good tool for the design of nanostractured materials, as discussed in the previous sections. It offers a flexible platform for a variety of nanomaterials with functionalities and robustness since one can combine BCP SA with a sol-gel process, nanoparticle synthesis, chemical vapor deposition, electrodeposition, or electroless deposition. Thus, in principle, the structural and material diversity obtained from the aforementioned techniques is substantial. This section introduces specific classes of material prepared from BCP-directed SA by the Wiesner group. 

Template-assisted electrodeposition is another important technique for synthesizing metallic nanomaterials with controlled shape and size. Arrays of nanostmctured materials with specific arrangements can be prepared by this method (Bera et al., 2004 Gurrappa and Binder, 2008). Template synthesis of nanomaterials is reported widely (Fumeaux et al, 1989 Martin, 1994 Hulteen and Martin, 1997 Schonenberger et al., 1997 ElGiar et al, 2000 Tiginyanu et al, 2008 Baranov et al, 2010). 

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