Degradation and Mineralization of Carbamazepine Using an Electro-Fenton Reaction Catalyzed by Magnetite Nanoparticles Fixed on an Electrocatalytic Carbon Fiber Textile Cathode

Abstract

Pharmaceutical wastes are considered to be important pollutants even at low concentrations. In this regard, carbamazepine has received significant attention due to its negative effect on both ecosystem and human health. However, the need for acidic conditions severely hinders the use of conventional Fenton reagent reactions for the control and elimination of carbamazepine in wastewater effluents and drinking water influents. Herein, we report of the synthesis and use of flexible bifunctional nanoelectrocatalytic textile materials, Fe_3O_4-NP@CNF, for the effective degradation and complete mineralization of carbamazepine in water. The nonwoven porous structure of the composite binder-free Fe_3O_4-NP@CNF textile is used to generate H_2O_2 on the carbon nanofiber (CNF) substrate by O_2 reduction. In addition, ·OH radical is generated on the surface of the bonded Fe_3O_4 nanoparticles (NPs) at low applied potentials (−0.345 V). The Fe_3O_4-NPs are covalently bonded to the CNF textile support with a high degree of dispersion throughout the fiber matrix. The dispersion of the nanosized catalysts results in a higher catalytic reactivity than existing electro-Fenton systems. For example, the newly synthesized Fe_3O_4-NPs system uses an Fe loading that is 2 orders of magnitude less than existing electro-Fenton systems, coupled with a current efficiency that is higher than electrolysis using a boron-doped diamond electrode. Our test results show that this process can remove carbamazepine with high pseudo-first-order rate constants (e.g., 6.85 h^(–1)) and minimal energy consumption (0.239 kW·h/g carbamazepine). This combination leads to an efficient and sustainable electro-Fenton process.