Nowadays, substances containing PFAS (Per- and polyfluoroalkyl substances) are widely used in various industrial applications due to their exceptional stability. However, their persistence and bioaccumulation have led to global environmental contam...
Nowadays, substances containing PFAS (Per- and polyfluoroalkyl substances) are widely used in various industrial applications due to their exceptional stability. However, their persistence and bioaccumulation have led to global environmental contamination and adverse health effects. Previous efforts to decompose PFAS using anode systems have been constrained by the use of expensive noble metal-based materials or heavy metal-based materials such as tin and nickel, raising concerns regarding economic feasibility and secondary pollution.
In this study, we explore the electrocatalytic decomposition of PFOA using carbon and copper-based cathode systems, capitalizing on their abundance and low cost. Initially, the challenge of hydrogen peroxide production using carbonized melamine foam (CMF) was addressed by passivating N6 sites, resulting in an improved passivated carbonized melamine foam (PCMF). This modification enhanced hydrogen peroxide production by approximately 60 % (> 90 μM min-1).
Further modification with copper phosphide (CuxP) demonstrated that hydrogen peroxide could be effectively converted into other reactive oxygen species (ROS) within the system. Cyclic voltammetry (CV) confirmed that the modified catalyst enhanced catalytic activity in the oxygen reduction reaction (ORR). The highest decomposition efficiency was achieved at pH 13, where superoxide anion radicals (O2 ) were identified as the primary agents of decomposition. Under highly alkaline conditions, the system generated ROS, including O2•⁻, which significantly contributed to the degradation process. In reuse tests, the polytetrafluoroethylene (PTFE)-modified electrode (PCMF-Cu) exhibited superior stability and reusability while maintaining catalytic activity. This improvement is attributed to PTFE acting both as a binder and a passivator.
This remarkable electrocatalytic system has significant potential for future studies on the decomposition of unclassified PFAS , suggesting that it provides a scalable and effective solution for the removal of difficult to decompose organic pollutants such as PFAS . Future studies will be able to apply this system to other pollutants and further improve the catalyst to enhance its performance.