Ultrathin iron-cobalt oxide nanosheets with enhanced H2O2 activation performance for efficient degradation of tetracycline

Ultrathin iron-cobalt oxide nanosheets (CoFe-ONSs) synthesized via a facile one-step routine by using NaBH4 as the reductant were used for H2O2 activation and tetracycline (TC) elimination. The CoFe-ONSs realized 83.5% removal of TC under the neutral conditions after 50 min with 0.3 g/L catalyst, 20 mM H2O2 and 50 mg/L TC. The effects of catalyst dosage, H2O2 concentration, initial pH, temperature, initial TC concentration, anions and water sources on TC degradation were studied. Hydroxyl ((OH)-O-center dot) radicals were the main active species in the entire reaction, which was demonstrated by quenching experiments, fluorescence detection and the electron paramagnetic resonance (EPR) technology. Additionally, the redox cycles of Fe-II/Fe-III and Co-II/Co-III were participated in (OH)-O-center dot generation. What's more, the plausible degradation pathways were put forward followed with detected intermediates. The CoFe-ONSs displayed negligible iron ions leaching and held high TC elimination performance even after five trials. Therefore, the CoFe-ONSs may expand the heterogeneous Fenton-like catalysts family and display great potential in eliminating antibiotic contaminants from wastewater.

Automated summary

The ultrathin iron-cobalt oxide nanosheets (CoFe-ONSs) synthesized using NaBH4 as the reductant exhibited high tetracycline removal efficiency under neutral conditions. Hydroxyl radicals were identified as the main active species, with redox cycles of Fe-II/Fe-III and Co-II/Co-III contributing to their generation.