Architecture engineering of Fe/FeO@MoS enables highly efficient tetracycline remediation via peroxymonosulfate activation: Critical roles of adsorption capacity and redox cycle regulation.

Design and synthesis of high-efficiency multicomponent nanostructure for activating peroxymonosulfate (PMS) to destruct emerging antibiotics remains a daunting challenge. We report herein the simplest one-step hydrothermal construction of hierarchical Fe/FeO@MoS architecture composed of MoS nanosheets integrated commercial FeO nanoparticles. The fabricated Fe/FeO@MoS architecture can be utilized as an efficient PMS activator to destruct tetracycline hydrochloride (TCH) with a removal efficiency of 90.3 % within 40 min, outperforming FeO nanoparticles, MoS nanosheets analogues and many MoS-based materials. The Fe/FeO@MoS/PMS works well under various reaction conditions, and SO and O are identified as major reactive oxygen species. Thirteen intermediates towards TCH destruction are detected via four pathways, and their acute/chronic toxicity and phytotoxicity are assessed. The origins of Fe/FeO@MoS/PMS system for efficient degrading TCH are ascribed to the synergy catalysis between FeO and MoS, which originate from: (a) the exposed Mo sites on catalyst surface facilitating high-speed electron transfer from MoS to Fe and accelerating the Fe regeneration; (b) the generated Fe serving as an excellent electron donor to jointly promote Fe/Fe redox cycle. This study provides a simple way to establish architecture for synergistically promoting PMS-mediated degradation.