Removal of arsenite by coupled electrocatalytic oxidation at polymer–ruthenium oxide nanocomposite and polymer-assisted liquid phase retention

Nanocomposite materials synthesized by incorporation of ruthenium oxide nanoparticles into a poly(pyrrole-alkylammonium) matrix have been characterized by transmission electron microscopy and by electrochemistry. Ruthenium oxide-based nanocomposites films coated onto carbon appeared efficient electrocatalysts for the oxidation of arsenic(III) into arsenic(V) species at a remarkable low potential, i.e. in the 0.3–0.5 V vs. Ag/AgCl range. Bulk electrocatalytic oxidation of arsenite solutions could be performed in the presence of a water-soluble poly(quaternary ammonium) salts acting as the supporting electrolyte and also as an As(V) complexing agent, which allowed to combine electrocatalytic oxidation of As(III) with the liquid phase polymer-assisted retention (LPR) technique to efficiently remove arsenic from polluted solutions.

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► A polymer–ruthenium oxide nanocomposite was electrosynthesized and fully characterized.
► Carbon electrodes were modified with films of this nanocomposite.
► The modified electrodes exhibited high catalytic activity toward As(III) oxidation.
► As(III) oxidation combined with ultrafiltration allowed efficient arsenic removal.