▎ 摘 要
Nano-dispersed Fe-0 and Fe3O4 on reduced graphene oxide (Fe-0/Fe3O4-RGO) was prepared and characterized. The prepared Fe-0/Fe3O4-RGO was used as a magnetically separable Fenton-like catalyst and showed superior catalytic activity compared to Fe3O4-RGO and Fe3O4 as well as other Fenton-like catalysts for the removal of phenol. The Fe-0/Fe3O4-RGO achieved 100% removal efficiency for phenol within 30 min. Free radical inhibition experiments and Electron Paramagnetic Resonance (EPR) showed that the main reactive species was (OH)-O-center dot rather than Fe-IV.High resolution TEM results revealed that nanoscale Fe-0 and Fe3O4 were uniformly dispersed and distributed on RGO without agglomeration, furnishing more active sites. The catalyst featured a unique mechanism of electron transfer-facilitated regeneration of active Fe2+ by nano-dispersed iron/graphene. RGO served as an effective mediator to facilitate the electron transfer from Fe-0 to equivalent to Fe3+ for the regeneration of equivalent to Fe2+, which was critical in the catalytic process. This electron transfer-facilitated regeneration of active Fe2+ resulted in a reusable catalyst with high catalytic activity for the removal of phenol. The nano-dispersed Fe-0/Fe3O4-RGO could be easily separated and recovered by magnetic field. The Fe-0/Fe3O4-RGO catalyst was reusable and the removal efficiency of phenol after 5 catalytic cycles was as high as 93%. The Fe-0/Fe3O4-RGO could be an effective Fenton-like catalyst for the treatment of waste water containing refractory phenol and phenol type pollutants.