Carbon-based materials electrochemical polymerization

A febrication procedure of bulk electrodes was first proposed by Lev s group [19] and was subsequently widely employed for the development of carbon ceramic electrodes. The common feature of these electrodes is the high content of carbonaceous materials. Generally, a sol is first mixed thoroughly with the desired amount of the carbon-based material. Then, the mixture is packed into one end of a plastic body that includes a stainless steel wire as an electrical contact (Figure 46.5). After sol condensation, polymerization, and gel drying, the resulting electrodes are polished to yield a smooth surface required for electrochemical measurements. In this setup, the sol-gel material, with or without nanomaterials, serves as a binder for the carbon-based conductive material. 

Nanocomposites of conducting polymers exhibit improved physicochemical and biological properties as compared to their individual counterparts. The integration of secondary component within conducting polymer leads to dramatic increase in different properties that are useful from an application point of view. Size, shape and controlled distribution of the dispersed phase are the critical factors to control the desired properties of a nanocomposite. Different approaches such as in situ synthesis, one-pot synthesis, electrochemical polymerization and vapor-phase polymerization have been employed to synthesize the nanocomposites of conducting polymers with metal or metal oxide nanoparticles, carbon-based materials, ternary nanocomposites, etc. All of these methods have certain advantages and drawbacks. Functional nanocomposites synthesized by these methods display many... 

Proposed electrode uses polymer deposited onto conducting substrate via electrochemical polymerization. Polymer is a poly-[Me(R-Salen) type. Me represents complex compound of transition metals (Ni, Pd Co, Cu, and Fe) with at least two different oxidation states. R represents electron donating substituent such as CH3 0-, C2H5O-, HO-, -CH3 radicals. Salen represents residue of bis(salicylaldehyde) ethylenediamine in Schiff s base. Preferences for conducting substrate include carbon fiber, carbon materials with metal coatings, and metal electrodes with high specific surface areas. 

Hashmi and Upadhyaya compared the electrochemical properties of the electrochemically synthesized MnO /PPy composite electrodes, fabricated with different electrolytes, namely polymer electrolyte film (polyvinyl alcohol [PVA]-HjPO aqueous blend), aprotic liquid electrolyte (LiClO -propylene carbonate [PC]), and polymeric gel electrolyte (poly methyl methacrylate [PMMA]-ethylene carbonate [EC]-PC-NaClO ) [60]. The cell with aqueous PVA-H PO showed non-capacitive behavior owing to some reversible chemical reaction of MnO with water, while the MnO / PPy composite was found to be a suitable electrode material for redox supercapacitors with aprotic (non-aqueous) electrolytes. The solid-state supercapacitor based on the MnO /PPy composite electrodes with gel... 

Template-based synthesis involves the fabrication of the desired material within the pores or channels of a nanoporous template. A template may be defined as a central structure within which a network forms in such a way that removal of the template creates a filled cavity with morphological and/or stereochemical features related to those of the template. Track-etch membranes, porous alumina, and other nanoporous structures have been characterized as templates. Electrochemical and electroless depositions, chemical polymerization, sol-gel deposition, and chemical vapor deposition have been presented as major template synthetic strategies. Template-based synthesis can be used to prepare nanostructures of conductive polymers, metals, metal oxides, semiconductors, carbons, and other solid matter... 

---