Air diffusion electrodes based on synthetized mesoporous carbon for application in amoxicillin degradation by electro-Fenton and solar photo electro-Fenton

The aim of this work was to develop an air diffusion mesoporous carbon electrode (ADE-MC) as cathode for the in-situ electrogeneration of hydrogen peroxide and its application on electro-Fenton (EF) and solar photo electro-Fenton (SPEF) processes. Three different mesoporous carbon materials were obtained by organic-organic self-assembly synthesis (soft-template route) by changing concentrations of resorcinol-formaldehyde polymer as carbon precursor and Pluronic F-127™ surfactant as matrix-forming agent. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), linear voltammetry (LV) and linear rotating disk electrode voltammetry (LV-RDE). MC materials showed pore diameter between 3.6 and 4.6 nm. The efficiency of ADE-MC was explored as a function of H₂O₂ produced at current densities (50, 100 and 150 mA cm⁻²). The highest production of H₂O₂ was 10.85 mmol L⁻¹ by applying 150 mA cm⁻². Finally, the ADE-MC were used for the mineralization of amoxicillin (50 mg L⁻¹), allowing complete degradation and mineralization percentages of 55% and 85% with EF and SPEF processes, respectively. MC electrodes produce H₂O₂ in enough amounts that provide a viable option to degradation and mineralization of others organic pollutants in aqueous media by EF and SPEF processes.