Effective removal of tetracycline hydrochloride from wastewater over porous Co3O4@NC/honeycomb ceramics by Fenton-like catalysis

The accumulation of antibiotics (as emerging pollutants) in water will produce adverse impacts on all aquatic living. Herein, the removal of tetracycline hydrochloride (TCH) was investigated on porous Co₃O₄@N doped C supported on honeycomb ceramics (Co₃O₄@NC-HC) Fenton-like catalysts. The enrichment of pyridine N, Co³⁺ surface active sites and oxygen vacancy (V_O) in Co₃O₄@NC-HC favors PMS activation to generate reactive oxygen species (ROS, such as ⋅OH, ⋅SO₄⁻, ⋅O₂⁻ radicals and ¹O₂) for TCH oxidation. The Co₃O₄@NC-HC catalysts exhibited excellent activity (84 % removal efficiency in the first 5 min at 35 mg L⁻¹ on 1.0Co₃O₄@NC-HC) and relatively good stability for Fenton-like TCH oxidation with PMS in the dark and a wide pH range (pH = 2–11). The related catalytic mechanism over Co₃O₄@NC/HC for TCH oxidation was investigated. The results of the toxicity evaluation showed that the toxicity of TCH was significantly reduced after degradation. The features of porous structure and large macroscopic size for Co₃O₄@NC-HC enable it to have a low fluid resistance and be easily recycled, which promotes its actual application.