One-step solvothermal construction of coral reef-like FeS2/biochar to activate peroxymonosulfate for efficient organic pollutant removal

Over the past few decades, organic pollution such as tetracyclines and dyes has caused harm to the environment, biology, and human health. Therefore, developing a green and efficient method for organic pollutant removal is urgent. Herein, a coral reef-like FeS 2 /C cs was successfully constructed by one-step solvothermal growth of FeS 2 on waste corn stalks-derived carbon. The as-prepared FeS 2 /C cs catalyst exhibited much better performance in activating peroxymonosulfate (PMS) for removing organic pollutants than the other candidates previously reported. Almost 100 % of oxytetracycline (OTC) could be degraded within 20 min. Various factors like PMS concentration, catalyst dosage, initial pH values, and temperature that influenced the degradation process were then investigated. Through quenching experiments and electron paramagnetic resonance (EPR), O 2 − , 1 O 2 , SO 4 − and OH were determined to be involved in attacking OTC, in which SO 4 − play a major role and OH acted as the secondary role. Subsequently, degradation pathways of OTC were rationally proposed. Toxicity simulations demonstrated that the toxicity of OTC could be effectively reduced after degradation. Universal experiments showed that FeS 2 /C cs  + PMS system could also effectively degrade other typical tetracyclines and dyes, such as tetracycline (TC, ∼100 %), chlortetracycline hydrochloride (CTC, ∼100 %), methylene blue (MB, ∼83 %) and rhodamine B (RhB, ∼95 %). Moreover, the FeS 2 /C cs could remain high catalytic activity in five cycles test. This study provides a green and efficient method for organic pollution removal and technical guidance for analyzing its environmental toxicology.