Degradation of polyvinyl chloride microplastics via an electro-Fenton-like system with a TiO2/graphite cathode

Nowadays, microplastic pollution has been brought into focus for its hazards to aquatic life. However, researches on the electrocatalytic treatment for efficient degradation of microplastics are still insufficient. Herein, an electro-Fenton like (EF-like) technology based on TiO2/graphite (TiO2/C) cathode was put forward to degrade polyvinyl chloride (PVC), a typical microplastic in water. It exhibited a remarkable performance on PVC degradation via cathodic reduction dechlorination and hydroxyl radical (OH) oxidation simultaneously. Besides, the effects of reaction temperature and initial PVC concentration were investigated. Under optimal conditions, the dechlorination efficiency of PVC reached 75 % after potentiostatic electrolysis at -0.7 V vs. Ag/AgCl for 6 h. The intermediate products were explored during the degradation of PVC microplastics. The surface morphologies and molecular weight of PVC changed accordingly. Based on these results, a possible degradation process for PVC was proposed. This work demonstrated that such a heterogeneous EF-like technology using TiO2/C cathode was hopefully to provide an eco-friendly method for microplastic wastewater treatment.