Reduction of hexavalent chromium by polypyrrole-modified steel mesh electrode

Adherent polypyrrole (ppy) films were electropolymerized from a para-toluenesulfonic sodium (PTS) solution on stainless steel mesh (SSM). Reduced ppy-modified SSM electrode can transfer Cr(VI) to Cr(III) effectively. Lower pH (< 2) or higher temperature (> 35 degrees C) is beneficial for the removal of Cr(VI). Electro-reduction achieved 90% removal efficiency after 21 min by cyclic voltammetry. The removal efficiency is 96-56% for one-six contact cycles between ppy and Cr(VI). SEM shows that ppy films on SSM have regular morphology with small nucleus of less than 1 mu m in diameter. (C) 2006 Elsevier Ltd. All rights reserved.