Electrocatalytic oxidation of As(III) to As(V) using noble metal–polymer nanocomposites

Nanocomposite materials synthesized by incorporation of Pt0 and Pd0 nanoparticles into a poly(pyrrole-alkylammonium) matrix have been characterized by transmission electron microscopy. These nanocomposites coated onto carbon electrodes present strong electrocatalytic properties towards the oxidation of arsenite to arsenate. Nanocomposite films modified electrodes have been used for As(III) analysis, with a detection limit reaching 2.4 μM (0.17 ppm). The interest of these nanocomposite electrode materials deposited onto carbon felt macroelectrodes for the exhaustive electrocatalytic oxidation of As(III) to As(V) solutions was also demonstrated. The use of a water-soluble poly(quaternary ammonium) salt acting both as supporting electrolyte and as extracting agent allowed us to efficiently remove the electrocatalytically generated arsenic(V) species by liquid phase polymer-assisted retention (LPR) technique.