Innovative CuxS-Based Electrodes for Scalable and Cost-Effective PFAS Electrochemical Treatment
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-11 |
| Journal | ECS Meeting Abstracts |
| Authors | Samaneh Yaghoobian, Manuel A. Ramirez-Ubillus, Ji Hyung Chung, YunâCheol Na, Lei Zhai |
Abstract
Section titled âAbstractâPer- and polyfluoroalkyl substances (PFAS), widely used in industrial and consumer products due to their chemical stability, are of growing environmental concern. These persistent pollutants, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been linked to adverse health effects such as cancer and immune dysfunction. Their strong carbon-fluorine bonds make them resistant to conventional treatments, necessitating advanced methods for their removal [1-5]. Among treatment methods, electrochemical oxidation (EO) has been demonstrated as an effective method for degrading PFAS in water, utilizing both direct electron transfer (DET) at the anode surface and indirect oxidation through the generation of highly reactive radical species on the anode. EO offers advantages such as direct mineralization of pollutants, rapid reaction rates, and operation under mild conditions without additional chemical oxidants. However, the effectiveness of EO strongly depends on electrode materials, which must balance efficiency, cost, and durability [4, 6-9]. High-performing electrodes, such as boron-doped diamond (BDD) or mixed metal oxide (MMO), are expensive and impractical for widespread use [4, 5]. Thus, developing alternative materials that achieve efficient PFAS degradation at a lower cost remains crucial. In this study, Cu x S compounds with different ratios between Cu 2 S and CuS were synthesized through hydrothermal method. Three copper sulfides were made, when controlling the ratio between Cu 2+ /Sulfur precursor. When L-cysteine was used (Cu/L-cysteine=3/2), pure Cu 2 S was obtained. On the other hand, when dithiocarbamate was used with a ratio of Cu 2+ /dithiocarbamate=1/2, CuS was obtained. Finally, when the ratio Cu 2+ /dithiocarbamate was 3/2, a mixture of Cu 2 S/CuS was synthesized. The dark brownish CuâS was spray-coated on nickel foam (NF) and copper foam (CF) to improve PFOA and PFOS removal. This cost-effective fabrication provided high electrical conductivity for efficient electron transfer, making it a more economical alternative to conventional high-cost electrode materials. The removal of PFOA and PFOS, both with the same initial concentration of 800 ppb, was investigated at a current density of 60 mA/cm 2 using electrodes of Cu x S on metals foams used as anode. The electrode CuS/NF showed removal efficiencies increased to 32.5% for PFOA and 57.3% for PFOS. Using copper foam as the substrate, CuâS/CF achieved a removal efficiency of 30.9% for PFOA and 82.4% for PFOS after 24 hours. Furthermore, the electrode Cu 2 S/CuS/CF exhibited a removal of 15.9% for PFOA and 69.1% for PFOS after 24 hours. Overall, the CuâS-based electrodes were demonstrated to be a promising sustainable catalyst for the electrochemical PFAS oxidation in water. References Rekik, H., et al., Per-and polyfluoroalkyl (PFAS) Eternal pollutants: sources, environmental impacts and treatment processes. Chemosphere, 2024: p. 142044. Sivagami, K., et al., Electrochemical-based approaches for the treatment of forever chemicals: removal of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from wastewater. Sci. Total Environ., 2023. 861 : p. 160440. Zeidabadi, F.A., et al., Structural dependence of PFAS oxidation in a boron doped diamond-electrochemical system. Environ. Res., 2024. 246 : p. 118103. Hwang, J.-H., et al., Nanoparticle-embedded hydrogel synthesized electrodes for electrochemical oxidation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Chemosphere, 2022. 296 : p. 134001. Lin, H., et al., Development of macroporous MagnĂ©li phase Ti4O7 ceramic materials: As an efficient anode for mineralization of poly-and perfluoroalkyl substances. Chem. Eng. J., 2018. 354 : p. 1058-1067. Wang, Y., et al., Foam fractionation and electrochemical oxidation for the treatment of per-and polyfluoroalkyl substances (PFAS) in environmental water samples. Chemosphere, 2023. 339 : p. 139615. Mirabediny, M., et al., Effective PFAS degradation by electrochemical oxidation methods-recent progress and requirement. Chemosphere, 2023. 321 : p. 138109. Schaefer, C.E., et al., Electrochemical treatment of perfluorooctanoic acid and perfluorooctane sulfonate: Insights into mechanisms and application to groundwater treatment. Chem. Eng. J., 2017. 317 : p. 424-432. Zeidabadi, F.A., et al., Electrochemical degradation of PFOA and its common alternatives: Assessment of key parameters, roles of active species, and transformation pathway. Chemosphere, 2023. 315 : p. 137743.