Conductivity nanoparticle film electrodes

Figure 27. Electron transport through a nanoporous film electrode after flash excitation. The potential jumps symbolize the grain boundaries between the individual particles. Under strong positive polarization (upper part) the transport occurs via deep traps, whereas only shallow traps are involved when the Fermi level at the back contact rises close to the conduction band of the nanoparticle.

Sharma et al. synthesized electrochemically the MnO -embedded PPy nanocomposite (MnO /PPy) thin-film electrodes for supercapacitors [56]. It was found that growing PPy polymer chains provided large surface area template that enabled MnO to form as nanoparticles embedding within the polymer matrix. The co-deposition of MnO and PPy had a complimentary action in which the porous PPy matrix provided high active surface area for the MnO nanoparticles and the MnO nanoparticles nucleated over polymer chains contributed to the enhanced conductivity and stability of the nanocomposite material by interlinking the PPy polymer chains. The SC of the nanocomposite thin-film electrode... 

Modification of electrode with conducting polymers can improve sensitivity, impart selectivity, and provide a support matrix for sensor molecules. These approaches are intensively studied for gas sensors, electroanalysis, and biosensors. The composite film of conducting polymers and metal nanoparticles on electrode often catalyzes electrode reactions (electrocatalysis). 

CB consists of spherical and usually dense carbon nanoparticles with a low SSA (usually below 120 m /g)" and because of their high electrical conductivity, they are a common conductive additive to film electrodes composed of porous carbons. Indeed, as shown in Refs. 37 and 117, adding CB to CDI film electrodes made from AC significantly improves the salt removal in saline electrolytes with 670, and 1000 ppm NaCl. The very low SSA, however, limits the CDI performance of electrodes purely composed of CB particles, as shown in Refs. 6,42, and 43. 

Nowadays, to increase sensitivity and selectivity of electrochemical applications, besides new techniques, chemical modification and functionalization of electrodes have also been conducted (Katz et al., 2004). In recent years, new electrode materials like GCPE and bismuth film electrode (BiFE) have been developed and applied to electrochemical biosensor systems (Anik et al., 2008 Timur and Anik, 2007 Wang et al., 2001). As mentioned earlier, nanomaterials like carbon-based nanomaterials, metallic nanoparticles, and nanoballs have been introduced into electrode structure... 

The newly developed CFE [32] (Fig. la), formed by covering a classical solid working electrode with a conductive carbon film, represents a very promising alternative to electrode surfaces modified by several carbon nanoparticles with profitable electrocatalytic properties (nanotubes, graphene, etc.). The smallest particles of micronized natural graphite (type CR 2 995, Graphite Tyn, Tjm nad Vltavou, Czech Republic) reach the size around 1,000 nm [33], which is very close... 

Lesniewski A, Paszewski M, Opallo M (2010) Gold-carbon three dimensional film electrode prepared from oppositely charged conductive nanoparticles by layer-by-layer approach. 

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