Efficient degradation of ibuprofen by electro-Fenton with microtubular gas- diffusion electrodes synthesized by wet-spinning method

Abstract Gas-diffusion electrodes (GDEs) are the efficient generator for the hydrogen peroxide, which plays an important role in the degradation of refractory organic contaminants by electro-Fenton processes. In this work, the microtubular gas-diffusion electrodes (MGDEs) were fabricated with the carbon nanotubes (CNTs) hollow fiber base by wet-spinning technology and then employed as gas-diffusion electrodes (GDEs). Characterized by FESEM, TEM, BET, XPS, the MGDEs were proved to be relatively compact and intact without fracture on the hollow fiber surface. Cyclic voltammetry test in three electrodes system was carried out to prove the catalysis effect of the surface functional groups in the electrochemical reactions. The time-course of H2O2 production rate in the range of the different current density (10 ~ 25 mA cm−2), pH value (3.0 ~ 9.0) and electrolyte concentration (0.01 ~ 0.1 M Na2SO4) were conducted to evaluated the electrochemical performance of MGDEs and explorer the optimal condition. The stability of electrocatalytic was also tested by repeated runs. Furthermore, several parallel-degradation process of the simulated wastewater with the 1.0 ~ 10.0 mg L-1 IBP were carried out in electro-Fenton system. Under the optimal conditions, the removal rate of IBP could reach 90.2% in 120 min with the pseudo first-order degradation rate constant of 0.01415 min−1. It shows the potential of this system to degrade NSAIDs.