Electrocatalytic degradation of perfluoroocatane sulfonate (PFOS) on a 3D graphene-lead dioxide (3DG-PbO2) composite anode: Electrode characterization, degradation mechanism and toxicity

• Published in: Chemosphere (Oxford) 2020-12, Vol.260, p.127587-127587, Article 127587
• Main Authors: Duan, Xiaoyue, Wang, Weiyi, Wang, Qian, Sui, Xinyu, Li, Na, Chang, Limin
• Format: Article
• Language: English
• Subjects: 3D graphene; Electrocatalytic oxidation; PbO2 anode; Perfluorooctane sulfonate; Toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.127587

In this work, a three-dimension grapnene-PbO2 (3DG-PbO2) composite anode was prepared using coelectrodeposition technology for electrocatalytic oxidation of perfluorooctane sulfonate (PFOS). The effect of 3DG on the surface morphology, structure and electrocatalytic activity of PbO2 electrode was investigated. The results indicated that the 3DG-PbO2-0.08 anode (3DG concentration in electrodeposition solution was 0.08 g L−1) possessed the best electrocatalytic activity due to its stronger ·OH radicals generation capacity, more active sites and smaller charge-transfer resistance. The degradation rate constant of PFOS on 3DG-PbO2-0.08 anode was 2.33 times than that of pure PbO2 anode. Additionally, the by-products formed in electrocatalytic degradation of PFOS were identified and a PFOS degradation pathway was proposed accordingly, which was dominated by the dissociation of –CF2- groups via the attack of ·OH radicals. Finally, the toxicity evolution of degradation solution was examined to evaluate the ecological risk of electrocatalytic oxidation of PFOS by acute toxicity assays to zebrafish embryos. [Display omitted] •The 3DG-PbO2 composite anode was prepared by coelectrodeposition technology.•The 3DG-PbO2 anode was used for electrochemical degradation of PFOS.•The degradation pathway of PFOS on 3DG-PbO2 anode was proposed.•The toxicity of PFOS degradation process was evaluated using toxic bioassays.