High electrocatalytic effect of palladium nanoparticle arrays electrodeposited on carbon ionic liquid electrode

A simple method for the fabrication of arrays of palladium nanoparticles on carbon ionic liquid electrode (CILE) is described. The ionic liquid, octylpyridinum hexafluorophosphate ([C8Py]+PF6-), is incorporated in the electrode as the binder. Pd nanoparticle arrays are directly formed on CILE surface by simple electrodeposition at -0.14 V from a 0.177 mM PdCl2 (in 1 M H2SO4, 0.15 M NH4PF6) solution. The presence of the ionic liquid on the electrode surface together with the favourable morphology of the electrode surface facilitates the formation of highly dispersed arrays of Pd nanoparticles on CILE. The resulting Pd nanoparticle-modified CILE displays unique electrocatalytic activity for the reduction of dissolved oxygen in basic, acidic and neutral media. For instance, in O-2-saturated 0.1 M KOH solutions, a well-defined voltammetric peak is obtained at -180 mV. The electrode also possesses attractive clectrocatalytic effects towards H2O2 oxidation and some biomolecules such as dopamine and ascorbic acid. (c) 2007 Elsevier B.V. All rights reserved.