Iron nanoparticles (Fe NPs) are known to be applied efficiently to remove organic and inorganic pollutants from wastewater effluents, particularly by means of advanced oxidation processes (AOPs) such as in Fenton and electro-Fenton treatments.^1,2 In these systems, surface-modified graphite felt electrodes were used either as anodes or as cathodes. Among other procedures, the surface modification of graphite felt cathodes has been achieved through the self-assembly of magnetite nanoparticles (Fe₃O₄ NPs).² As for the modification of graphite felt anodes, the electrodeposition of gold nanoparticles (Au NPs) has been found to minimize the overall consumption of energy during electro-Fenton treatment operations, as opposed to most wastewater treament methods.³

In our research we are modifying the surface of graphite felt electrodes, by depositing Fe₃O₄ NPs on the cathode and Au NPs on the anode, in order to achieve high oxidation rates of organic compounds in aqueous systems. According to our calculations, a cell containing these combined electrodes are meant to operate under favourable energetic conditions in a range close to 200 mV and 18.1 mW m^-2. These results are currently being optimized by controlling the electric charge distributed on the modified surface of these electrodes. On the other hand, we are also studying the use of magnetic interactions to remove paramagnetic probe species from aqueous phase in contact with graphite felt surfaces containing Fe₃O₄ NPs. Our preliminary results show that above 60% of such paramagnetic species can be removed by applying this method, which would enhance the efficiency in wastewater treatment processes.

References

1. Shahwan, T., Sirriah, S. A., Nairat, M., Boyacı, E., Eroğlu, A. E., Scott, T. B., & Hallam, K. R. (2011). Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes. Chemical Engineering Journal, 172(1), 258-266.
2. Do, T. M., Byun, J. Y., & Kim, S. H. (2017). An electro-Fenton system using magnetite coated metallic foams as cathode for dye degradation. Catalysis Today, 295, 48-55.
3. Le, T. X. H., Esmilaire, R., Drobek, M., Bechelany, M., Vallicari, C., Nguyen, D. L., & Cretin, M. (2016). Design of a novel fuel cell-Fenton system: a smart approach to zero energy depollution. Journal of Materials Chemistry A, 4(45), 17686-17693.