Fe@Fe₂O₃ Core−Shell Nanowires as an Iron Reagent. 3. Their Combination with CNTs as an Effective Oxygen-Fed Gas Diffusion Electrode in a Neutral Electro-Fenton System

Abstract

In this study, core−shell Fe@Fe2O3 nanowires and multiwall carbon nanotubes (CNTs) were combined with poly(tetrafluoroethylene) (PTFE) and then used as an oxygen-fed gas diffusion electrode. The resulting Fe@Fe2O3/CNT composite electrode was examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). A novel electro-Fenton (E-Fenton) system was established with the resulting gas diffusion cathode, where hydrogen peroxide was electrogenerated by the reduction of O2 adsorbed on the cathode and iron ions were produced by the slow leakage of Fe@Fe2O3 nanowires, simultaneously. The degradation of rhodamine B (RhB) in this E-Fenton system reached 91.5% in 120 min at neutral pH, indicating this system is very promising for wastewater treatment. Moreover, cyclic voltammetry (CV) experiments were performed to probe the reactions on the Fe@Fe2O3/CNT electrode.