Synergistic heterogeneous catalysis: MoS2/α-FeOOH nanocomposites for pH-universal PMS activation and efficient antibiotic degradation

Abstract

The development of high-efficiency catalysts for advanced oxidation processes is crucial for environmental remediation. In this study, a novel α-FeOOH/MoS₂ heterojunction catalyst was designed to address the intrinsic limitations of Fe-based materials in peroxymonosulfate (PMS) activation. By integrating MoS₂ nanoflowers with α-FeOOH nanorods, the nanocomposite catalyst exhibited an expanded specific surface area and improved interfacial charge transfer, facilitating accelerated redox cycling between Mo(IV/VI) and Fe(II/III) species. This synergistic interaction significantly enhanced PMS activation efficiency, enabling the near-complete degradation (∼99 %) of tetracycline (TC) within 30 min. The reaction rate was notably amplified, surpassing the performance of individual α-FeOOH and MoS₂ components by factors of 9.7 and 21.6, respectively. Moreover, the nanocomposite catalyst demonstrated robust degradation performance across a broad pH range (3–11) and maintained high efficiency under varying PMS dosages and pollutant concentrations. Mechanistic investigations through electron spin resonance (ESR) and radical quenching experiments confirmed the involvement of multiple reactive species, including sulfate radicals (SO₄^•−), superoxide radicals (O₂^•−), hydroxyl radicals (•OH), and singlet oxygen (¹O₂). These findings highlight the potential of α-FeOOH/MoS₂ heterojunctions as advanced, sustainable catalysts for wastewater treatment and environmental purification.