Electrochemical degradation of methyl orange on Pt–Bi/C nanostructured electrode by a square-wave potential method

Abstract

Electrochemical methods usually enable more efficient degradation of recalcitrant pollutants than biological approaches, but their treatment performance relies heavily on the applied catalyst and the energy consumption. Here, a novel method was established for effective degradation of methyl orange (MO) by a combined use of a platimum–ismuth bimetallic carbon paper (Pt–Bi/C) nanostructured electrode and a square-wave potential regime. Unlike the conventional electrochemical approaches that employ electrochemical oxidation or reduction solely, the square-wave potential approach integrates both processes via alternate electrochemical oxidation and reduction reactions. The surface properties and electrochemical performance of the prepared Pt–Bi/C nanostructured electrode were comprehensively evaluated. The MO degradation in this system was compared to those with other electrodes and different applied potentials, and the enhanced degradation mechanism was explored. In our system, a highest MO degradation of over 95.6% was achieved within 180min. The oxidation and reduction processes both contributed to the degradation. This work offers an effective method for enhancing degradation of dyes and may hopefully be also applied for treatment of other recalcitrant compounds in water and wastewater.