Electrochemical oxidation of perfluorooctanoic acid over Ti-MoNTA/Sb-SnO₂/PbO₂-PTFE modified anode

Perfluorooctanoic acid (PFOA) is very stable in environment and harmful to ecosystems and human health. Electrochemical oxidation is one of the methods for efficient removal of perfluorooctanoic acid, but it is usually affected by factors such as anode material and energy consumption. Ti-MoNTA/Sb-SnO2/PbO2-PTFE electrode was prepared by using Ti-Mo mixed oxide nanotube array substrate and PTFE doped lead dioxide (PbO2). TheTi-MoNTA/Sb-SnO2/PbO2-PTFE electrode had higher oxygen evolution potential (1.97 V), longer service life (133.7h) and lower charge transfer resistance (5.26 Ω) than the Ti/Sb-SnO2/PbO2 electrode prepared under the same process. Under the experimental conditions of this study, the total organic carbon (TOC) removal rate of PFOA, the defluorination rate and the energy consumption over Ti-MoNTA/Sb-SnO2/PbO2-PTFE electrode was 82.3 %, 45.2%, and 2.76 kWh·g -1 TOC, respectively, which were much better than that of Ti/Sb-SnO2/PbO2 electrode. Both the two electrodes had good cycle stability.