Electrochemical fabrication of polyaniline films deposited on graphene-loaded electrodes for •OH production and perfluorooctanoic acid degradation

The present study describes the coating of modified graphite felt (GF) with graphene (GE) and polyaniline (PANI). GF was doped with nitrogen atoms by a series of modification and electrolytic deposition. Tests of different types of N content and cathodic catalytic oxidation performance confirmed that the graphite N introduction promoted the production of H2O2 in the 2e- process. Pyridine N catalyzed the H2O2 decomposition to produce center dot OH. The amount of H2O2 produced by GF, GF-GE, and GF-GE@PANI system was 11 mg L-1, 70 mg L-1, and 180 mg L-1, respectively. The doping of graphene increased H2O2 yield, and the electrolytic deposition of PANI converted H2O2 to center dot OH rapidly. It was proved that the N atom provided by graphene was graphite N, which was the active catalytic site for the production of H2O2. The perfluorooctanoic acid (PFOA) removal at 180 min was 24.1% and 49.8% in the GF and GF-GE systems, respectively. The GF-GE@PANI system achieved 100% PFOA removal within 160 min. It was demonstrated that the enrichment of PANI with pyridine N provided many active sites for improving the conversion of H2O2 to center dot OH and in-situ degrading organic pollutants, offering an alternative for wastewater treatment.

Automated summary

This study demonstrated that coating modified graphite felt with graphene and polyaniline could enhance the production of H2O2 and the removal of organic pollutants in wastewater treatment, offering a promising alternative approach.