Fe3O4 derived from the decomposition of siderite as a heterogeneous photocatalyst to degrade 2,4-dichlorophenol via activating PMS

This study showcases the performance of Fe3O4 (S600) derived from the decomposition of siderite in activating peroxymonosulfate (PMS) for the 2,4-dichlorophenol (2,4-DCP) degradation, as well as the enhancement of visible light in the S600/PMS system. With the involvement of visible light, 2 g/L Fe3O4 and 0.5 mM PMS achieved 100 % degradation of 2,4-DCP within 70 min. Singlet oxygen (1O2) and hydroxyl radicals (OH) were the primary reactive species responsible for 2,4-DCP degradation under visible light irradiation based on the scavenging experiments and electron paramagnetic resonance (EPR) analysis. Importantly, compared to the absence of visible light, the visible light boosted 1O2 production and accelerated 2,4-DCP degradation. The effects of various operating parameters on the degradation efficiency were also examined, and the intermediates and possible degradation pathways of 2,4-DCP were identified. This study proves that the integrated utilization of natural siderite derivatives to activate oxidants for pollutant degradation is a promising approach.