Ionizing radiation-assisted in-situ synthesis of nitrogen-doped graphene oxide-supported nano Fe3O4 for PMS activation to degrade emerging pollutants

This study firstly reported the in-situ preparation of nitrogen-doped graphene oxide-supported nano Fe 3 O 4 (Fe 3 O 4 @NRGO) by ionizing radiation . The conversion of Fe(II) to iron oxide was modulated by absorbed dose in solution, which regulated the catalytic activity of Fe 3 O 4 /NRGO. When the initial concentration of Fe(II) was 0.5 mM and the absorbed dose was 10 kGy, the as-prepared catalyst (Fe 3 O 4 @NRGO-10) showed superior catalytic activity for activating peroxymonosulfate (PMS) to degrade phenol. In the presence of 0.4 mM PMS and 0.5 g/L Fe 3 O 4 @NRGO-10, the pseudo first-order kinetic rate of phenol degradation reached 0.0286 min −1 . Sulfate radicals, hydroxyl radicals and high-valent iron oxo made major contribution to phenol degradation. The superior catalytic activity of Fe 3 O 4 @NRGO-10 might be attributed to the synergistic effect of NRGO and Fe 3 O 4 , in which NRGO promoted the conversion of Fe(III) to Fe(II). Fe 3 O 4 @NRGO-10 exhibited good stability in the cycling experiments. In addition to phenol, the Fe 3 O 4 @NRGO-10/PMS system could degrade sulfamethoxazole, bisphenol A and atrazine, indicating the wide applicability. This study reported a facile way to prepare carbon-supported metal oxide catalysts and convenient way to modulate the catalytic activity by absorbed dose.