Polyoxometallate-modified conducting polymer linked Pt nanoparticles as bifunctional electrocatalysts for bromate reduction
|Malgorzata Chojak , Aneta Kolary , Paweł J. Kulesza|
Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland
Recently, there has been tremendous interest in the fabrication and characterization of monolayer and multilayer organized assemblies at solid surfaces that produce functionalized interfaces with well-defined composition, structure, thickness and reactivity. Attractiveness of the self-assembly technique includes the possibility of controlled and sequential formation of any number of layers of different composition (e.g. of oppositely charged polyelectrolytes, ultra-thin films of conjugated polymers) on a large variety of substrates. Also the possibility of stabilizing of nanoparticles and their organization into two-dimensional arrays and three-dimensional networks have prompted the increased interest due to their potential applications in many areas including sensors, catalysis and electrocatalysis.
An important possibility arises from the adsorption of inorganic monolayers. Among rigid inorganic templates, polyoxometallates are particularly attractive because of their ability to adsorb irreversibly on solid surfaces [1,2] as well as on metal nanoparticles (e.g. platinum and their alloys) .
In the present study, we demonstrate that the electrodes modified with PMo12-covered platinum nanoparticles (inter-connected via polypyrrole layers as demonstrated in Scheme) exhibit remarkable electrocatalytic effect on the reduction of bromate, a highly toxic substance (carcinogen), which may be present in drinking water when ozonation is applied in the treatment of bromide-containing water. An important issue is the bifunctional electrocatalytic effect originating from the ability of both Pt and PMo12 to induce reduction of bromate. What is analytically important, PMo12 (that is chemisorbed on Pt) inhibits platinum reactivity towards proton discharge and decrease background currents.
 D. Inersoll, P. J. Kulesza, L. R. Faulkner, J. Electrochem. Soc., 141 (1996) 140.
Presentation: Short communication at SMCBS'2005 Workshop, by Malgorzata Chojak
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-08-02 15:33 Revised: 2009-06-07 00:44