Multi-layer PEDOT:PSS/Pd composite electrodes for hydrazine oxidation

Abstract

In this paper, a simple and stable composite electrode PEDOT:PSS/Pd based on the intrinsically conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was fabricated by drop-casting. The preliminary formation of water dispersion of PEDOT:PSS with Pd nanoparticles was followed by multistep drop cast deposition for the formation of thin metal-polymer composite layers on glassy carbon electrode. The morphology of pristine and composite films as well as the size and distribution of Pd particles were characterized by scanning electron microscopy. The electrochemical properties of composite metal-polymer layers were examined by cyclic voltammetry and chronoamperometry in solution of 0.2 M phosphate buffer solutions (PBS) in the presence and absence of hydrazine. It was demonstrated that electrocatalytical oxidation of hydrazine takes place only on electrochemically accessible palladium particles, located on surface or near-surface layers of composite film. The proposed multi-layer electrodes exhibited a wide linear range of response towards hydrazine detection (from 0.4 to 100 μM) and low detection limit of 0.12 μM (S/N = 3).