Electrochemically removal of nitrate at Ni/PPy nanowires modified electrodes

Polypyrrole (PPy) nanowires were prepared by template-free method electrochemically on the surface of graphite electrode. The Ni/polypyrrole nanowire (Ni-GS) and Ni/polypyrrole cauliflower (Ni-PS-CF) modified graphite electrodes were prepared by electrodeposited Ni on the different electrodes. The electrocatalytic activity of Ni/PPy nanowires (Ni- GS) and Ni/PPy cauliflower (Ni-GS-CF) modified graphite electrodes towards nitrate were characterized by electroreduction of nitrate and their reduction products. The effect of solution pH, electrolytic potentials and electrolytic current density on nitrate electrolysis and the products were also examined. The experimental results indicate that the suitable electrolytic condition toward nitrate on the modified electrodes is at low pH, higher potential and medium current density, at the meantime, also indicate that the Ni-GS modified electrodes can effectively reduce nitrate and have high electrocatalytic activity toward nitrate than the Ni-GS-CF modified graphite electrode. And the the products of nitrite and ammonia are always at low concentratio. So the Ni-GS nanowires modified electrodes have promising application in environmental remediation.