Magnetic Fe3O4-deposited flower-like MoS2 nanocomposites for the Fenton-like Escherichia coli disinfection and diclofenac degradation


Fenton reaction can disinfect bacteria and degrade organic pollutants via the generation of OH through the reaction of Fe(II) and H2O2. However, its high efficiency only at very acidic conditions and the formation of Fe(III) sludge limit its practical application. Herein, magnetic Fe3O4-deposited flower-like MoS2 (MF) composites were fabricated to disinfect Escherichia coli and degrade diclofenac (DCF) with addition of small amount of H2O2 at a wide pH range (from 3.5 to 9.5). MF can efficiently inactivate bacteria and remove DCF at broad pH from 3.5 to 9.5. For example, 1.2 × 106 CFU mL-1 cells are completely disinfected by MF in 30 min at pH 6 with 5 mM H2O2, while 10 mg L-1 DCF is fully degraded in 7 min at pH 6 with 1 mM H2O2. MoS2 facilitates the conversion cycle of Fe(III)/Fe(II) and improves the generation of OH. MF can be easily collected by magnet after use. Confocal image, SEM images, the leakage of K+ and DNA were employed to determine the damage of cell membrane. Meanwhile, the theoretical density functional theory and the degradation intermediates determination were employed to provide the degradation pathway of DCF. MF exhibit excellent reusability and good catalytic performance towards sanitary sewage.