Spatial Distribution of Electrodeposited Metal Particles

An illustration of the role of the oxidation state in the distribution of the metal particles across the CP layer was presented in single-step potential deposition experiments on platinum in sulfonated PANl that were carried out at two values of the potential (-0.2 and -1-0.2 V vs. Ag/AgCl reference electrode), corresponding to the reduced and oxidized states of PANI [ 101 ]. In the first case a homogeneous distribution of Pt across the entire CP layer up to the underlying carrying substrate was observed, whereas in the second case (oxidized PANI) the Pt content decreased steeply within a narrow region close to the polymer/solution interface [101]. 

The design of subtle specific methods for depositing metal NPs, e.g. [144,145] is another way to control the location of the metal deposit within the CP layer. One proposed approach involves the deposition of a thin, sacrificial Au layer on a Pt substrate, electropolymerization of PANI on the Au-plated substrate, gold oxidation in chloride solution, and finally reduction of the AuCU eomplexes entrapped in the PANI structure. Thus gold/ polyaniline free-standing eomposite films are produced [144,145]. 

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