Potential‐Driven Anchoring of Toxic Dyes from Wastewaters Using Renewable Conductive Polymer Film Deposited on Iron Electrode

In this study, an eco‐friendly, renewable electrochemical adsorption method is developed using a conducting polyaniline (PAni) film electrodeposited on a low‐cost iron (Fe) surface. Electropolymerization of PAni film from aniline monomer onto an ordinary grade Fe surface, which is impossible in a strong acid solution, was successfully carried out using oxalic acid. The PAni/Fe electrodes were characterized with state‐of‐the‐art techniques. Stone‐like particles with a wide distribution of sizes of PAni formed on the Fe surface, which possessed a direct band gap with an energy of 1.54 eV. The PAni film formed on the Fe electrode exhibited redox properties. This film showed enhanced capacity for the removal of cationic dye in the presence of complex oxalate ions. The efficiencies of removal at optimized conditions were 95% and 40% for the cationic and anionic dyes, respectively. The recovery of the PAni film was found to be possible by tuning the redox sites of the polymer through a simple change in the solution pH. This study would assist in developing a simple, cost‐effective, and efficient method for a large‐scale application in removing charged organic species from wastewaters in a renewable manner.