Preparation of ternary reduced graphene oxide/CoFe2O4@N atom-doped carbon aerogel for efficient tetracycline degradation in Fenton-like reaction

In peroxymonosulfate (PMS)-based Fenton-like reaction, how to simultaneously improve the catalytic activity and suppress the metal leaching was a difficult question. Herein, a reduced graphene oxide/CoFe2O4@N atomdoped carbon (rGO/CoFe2O4@NC) aerogel was prepared through a simple two-step process. In the aerogel, the three-dimensional hierarchical structure provided a large surface area and good adsorption, leading to the enhanced local tetracycline (TC) concentration and accelerated degradation rate. On the other hand, the metal leaching was remarkably reduced, due to the protective NC layer covered on the CoFe2O4 surface. In PMS-based Fenton-like reaction, rGO/CoFe2O4@NC aerogel exhibited outstanding catalytic activity, and TC degradation rate was 2.0 x 10- 2 L center dot mol- 1 center dot min- 1, much higher than the individual component, including rGO aerogel, CoFe2O4 nanoparticles and NC nanoparticles. Meanwhile, the metal leaching was greatly suppressed to 0.045 and 0.43 mg/L, completely met the China Emission standard. Radical trapping experiments and electron paramagnetic resonance analysis were employed to investigate the possible radicals, and their contributions in TC degradation were also evaluated, where 1O2 was found to be the primary radicals in the Fenton-like reaction. This study presented a simple strategy to prepare catalysts with high activity and low leaching for environmental remediation.