Architecture engineering of Fe/Fe2O3@MoS2 enables highly efficient tetracycline remediation via peroxymonosulfate activation: Critical roles of adsorption capacity and redox cycle regulation

Abstract

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/Fe₂O₃@MoS₂ architecture composed of MoS₂ nanosheets integrated commercial Fe₂O₃ nanoparticles. The fabricated Fe/Fe₂O₃@MoS₂ 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 Fe₂O₃ nanoparticles, MoS₂ nanosheets analogues and many MoS₂-based materials. The Fe/Fe₂O₃@MoS₂/PMS works well under various reaction conditions, and SO₄^•- and ¹O₂ 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/Fe₂O₃@MoS₂/PMS system for efficient degrading TCH are ascribed to the synergy catalysis between Fe₂O₃ and MoS₂, which originate from: (a) the exposed Mo⁴⁺ sites on catalyst surface facilitating high-speed electron transfer from MoS₂ to Fe³⁺ and accelerating the Fe²⁺ regeneration; (b) the generated Fe⁰ serving as an excellent electron donor to jointly promote Fe³⁺/Fe²⁺ redox cycle. This study provides a simple way to establish architecture for synergistically promoting PMS-mediated degradation.

Keywords: Fe(2)O(3); MoS(2); Peroxymonosulfate activation; Radical/non-radical mechanism; Tetracycline degradation.