Polypyrrole–gold nanostructured composite, active and durable electrocatalytic material

Abstract

The consequences of treatment of gold nanocrystals present in polypyrrole-gold composites and electrodeposited gold nanocrystals (PPY-Au and Au NPs) with OH radicals generated in Fenton's reaction were investigated. Particularly, the changes in the morphology and the electrochemical properties of those materials are shown. For both materials, the etching effect was noticed. Contrary to significantly reduced catalytic activity, the changes observed in size and shape of gold nanostructures were less pronounced. In the case of PPY-Au composite material, the etching effects were less intense. Even after a 60-min radical treatment of the PPYAu composite material, the gold-nanocrystal catalytic activity remained high. The limited dissolution of the gold nanocrystals in the PPY-Au composites, compared to bare Au NPs, can be explained by the presence of the polymer which served as a kind of protective barrier against the oxidizing agent. A decrease in the electrocatalytic properties vs. the electrooxidation of ethanol of both forms of gold nanocrystals were observed after the treatment with hydroxyl radicals.