Elucidating Visible‐Light Photocatalytic Degradation of Organophosphorus Residues Over Reduced Graphene Oxide/Iron‐Manganese Mixed Oxides Composite

In this work, a ternary Fe 2 O 3 /Mn 2 O 3 /reduced graphene oxide (FM/rGO) composite was prepared via a rapid microwave‐assisted coprecipitation method. The engineered composite exhibited exceptional visible‐light‐driven photocatalytic activity as compared to both single Fe 2 O 3 and Fe 2 O 3 /Mn 2 O 3 (FM) heterojunction, achieving nearly complete degradation of parathion, a resistant organophosphorus pollutant, within 60 min accompanied by a remarkable mineralization (∼86% TOC removal). Kinetic analysis confirmed that the degradation complies with a pseudo‐first‐order model with a significant rate of 0.0597 min −1 . Comprehensive photoelectrochemical measurements revealed that the Type‐I FM heterojunction and the highly conductive rGO network facilitate efficient charge transfer. Interestingly, the coexistence of mixed‐valence transition metals (Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ ) alongside a high density of π bonds in rGO carriers served as dynamic electron traps, effectively accelerating spatial charge separation and suppressing electron‐hole recombination. Radical scavenging and GC‐MS analyses identified critical roles of hydroxyl radicals (•OH) for the P─O–aryl bond cleavage. Furthermore, the FM/rGO composite demonstrated practical magnetic recoverability and outstanding cyclic stability, providing a robust and highly efficient photocatalytic platform for hazardous pollutant remediation.