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

• The rapid method of electro-deposition was used to load PANI on GF. • It overcomes the secondary pollution coming from traditional EF. • Graphite N was the active catalytic site for the production of H2O2. • Pyrrolic-N enhanced the PFOA adsorption capacity of the cathode. 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 H 2 O 2 in the 2e - process. Pyridine N catalyzed the H 2 O 2 decomposition to produce •OH. The amount of H 2 O 2 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 H 2 O 2 yield, and the electrolytic deposition of PANI converted H 2 O 2 to •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 H 2 O 2 . 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 H 2 O 2 to •OH and in-situ degrading organic pollutants, offering an alternative for wastewater treatment.