Enhanced electro-Fenton degradation of tetracycline in aqueous solution using a self-supported BiOCl/CF cathode

The cathode material is critical to the yield of hydrogen peroxide (H2O2) and electro-Fenton (EF) performance. In this work, bismuth oxychloride (BiOCl) as one of the representatives of ternary oxides was grown in situ on carbon felt (CF) through a simple solvothermal method and employed directly as a self-standing cathode for the EF degradation of the target contaminant tetracycline (TC). TC can be almost completely degraded, up to 95% in 90 min under the heterogeneous EF process. The characterizations demonstrated that the BiOCl/CF electrode exhibited excellent conductivity due to CF as the supporting carbon material with a 3D network structure; meanwhile, this hybrid electrode also possessed abundant active sites attributed to the decorated BiOCl having rich oxygen defects. Finally, the rational reaction mechanism of TC was also elucidated by the X-ray photoelectron spectroscopy (XPS) spectrum, free radical quenching experiments and electron paramagnetic resonance (EPR) spectra, in which hydroxyl radicals (c OH) were considered as the dominant active oxidants and BiOCl had a synergistic effect on in-situ generation and decomposition of H2O2.

Automated summary

In this study, a self-standing cathode material was prepared by in situ growing bismuth oxychloride on carbon felt, and it was used for the electro-Fenton degradation of tetracycline. The hybrid electrode exhibited excellent conductivity and abundant active sites, leading to the almost complete degradation of tetracycline within 90 minutes.