Electrochemical oxidation of PFOA in aqueous solution using highly hydrophobic modified PbO2 electrodes

The hydrophobic polyvinylidene fluoride (PVDF) was doped in PbO2 anode through coelectrodeposition method. The morphology, structure, and contact angle of the electrode were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and contact angle goniometer. Electrochemical properties were determined by linear sweep voltammetry (LSV) and accelerated life test. Experimental results showed that PVDF-doped PbO2 still possessed β-PbO2 crystallographic structures. Contact angle, oxygen evolution potential, and life span increased with PVDF doped amount. The oxygen evolution potential of Ti/SnO2-Sb2O5/PbO2-PVDF (1 wt%) was 1.83 V (vs. saturated calomel electrode, SCE). Results of the accelerated life tests of different anodes illustrated that 45.75 h for Ti/SnO2-Sb2O5/PbO2-PVDF (1 wt%) was much longer than the 8.37 h for Ti/SnO2-Sb2O5/PbO2 and 2.45 h for Ti/PbO2. Approximately 92.1% of perfluorooctanoic acid (PFOA) degradation was achieved in 180 min at initial pH 3 at applied current density of 40 mA/cm2 at Ti/SnO2-Sb2O5/PbO2-PVDF (1.0 wt%).