Nano-flowers FeS/MoS2 composites as a peroxymonosulfate activator for efficient p-chlorophenol degradation

The degradation of organic pollutants in water is a critical environmental challenge. The iron-doped MoS₂ catalysts have demonstrated potential in activating peroxymonosulfate (PMS) for environmental remediation, but they face challenges such as poor conductivity, limited electron transfer efficiency, and a scarcity of active sites. To address these issues, we successfully synthesized a nano-flowers FeS/MoS₂ composite derived from polyoxometalates (NH₄)₃[Fe(III)Mo₆O₂₄H₆]·6H₂O (denoted as FeMo₆) as the bimetallic precursors. This synthesis strategy enhances the interaction between FeS and MoS₂, thereby facilitating electron transfer. Notably, the introduction of sulfur vacancies in FeS/MoS₂ exposes additional Mo⁴⁺ active sites, promoting the redox cycle of Fe²⁺/Fe³⁺ and accelerating the regeneration of Fe²⁺, which in turn enhances PMS activation. Therefore, a catalytic oxidation system of FeS/MoS₂/PMS is presented that primarily relies on SO₄^·− and ·OH, with ¹O₂ as a supplementary oxidant. This system exhibits exceptional degradation efficiency for p-chlorophenol (4-CP), achieving 100% degradation within 10 min over a wide pH range of 2.4–8.4. The robust performance and wide applicability of FeS/MoS₂ catalyst make it a promising candidate in advanced oxidation processes (AOPs) for environmental remediation.