High-performance iron-doped molybdenum disulfide photocatalysts enhance peroxymonosulfate activation for water decontamination

Although Fe-based catalysts for peroxymonosulfate (PMS) activation for environmental remediation are effective, the poor regeneration of ferric (Fe (III)) to ferrous ions (Fe (II)) in conventional Fe-based catalysts compromises the durability of PMS activation. Given this, an iron-doped molybdenum disulfide MoS2 (Fe-MoS2) catalyst was prepared via a one-step hydrothermal method, and it was demonstrated to sustain PMS activation for removing tetracycline hydrochloride (TCH) from aqueous solution under visible-light irradiation. The as-prepared Fe-MoS2 catalysts feature dual metallic active sites of Fe and Mo atoms to enhance photoelectrons production from MoS2 for Fe (II) regeneration, thereby preventing iron leakage. Moreover, the Fe-MoS2 catalysts exhibited good recyclability, enabling multiple cycles of TCH degradation in the presence of PMS under the irradiation of visible-light. In addition, we confirmed that the generated radicals (SO4•−, O2•−, and •OH) and non-radical species (1O2 and h+) were responsible for TCH degradation. We also determined critical intermediates during TCH degradation and proposed TCH degradation pathways. This study develops a high-performance Fe-doped MoS2 photocatalyst for PMS activation and paves the way for leveraging dual metallic sites on catalysts for enhancing water purification.