Activation of Fenton reaction by controllable oxygen incorporation in MoS2-Fe under visible light irradiation

Highlights: • Oxygen-incorporated MoS₂ is firstly researched as a Co-catalyst in Fenton system. • A complete MB degradation can be quickly achieved on oxygen-incorporated MoS₂-Fe. • Faster conversion of Fe²⁺/Fe³⁺ was achieved after oxygen incorporation in MoS₂. MoS₂ could be used as co-catalysts to accelerate the conversion of Fe²⁺/Fe³⁺ in Fenton reaction. However, the basal plane of pristine MoS₂ was catalytically inert, which limited the promotion to Fenton process. Thus, improving the co-catalytic activity of MoS₂ via microstructural regulation is crucial to further enhance the Fenton performance. In this work, we incorporated oxygen into MoS₂ structure and fabricated oxygen-incorporated MoS₂-Fe as a heterogeneous Fenton catalyst for the first time. After controllable oxygen incorporation engineering, MoS₂ showed optimized band structure, better optical response ability, superior electrons transformation and more catalytic sites for Fe³⁺ reduction through the synergetic effect of photocatalysis and redox, leading to an extraordinary performance for methylene blue (MB) degradation in H₂O₂ + visible light system. According to the results of quenching experiments and EPR tests, ·O₂^– and HO· were confirmed as the direct species to decompose MB molecule during reaction. Other experimental conditions, such as pH effect, dosage influence and effectiveness of various organics, were also explored. This novel strategy of oxygen incorporation in MoS₂-Fe was an efficient way to enhance Fenton activity and was meaningful for environmental remediation in the future.