Degradation of trichloroethylene by activated persulfate using a reduced graphene oxide supported magnetite nanoparticle

• nFe3O4/rGO was successfully prepared and characterized as persulfate activator.
• TCE was efficiently degraded at a wide range of pH from 3.0 to 11.0.
• High TOC removal and dechlorination efficiency were achieved.
• The possible mechanism of persulfate activation by nFe3O4/rGO was interpreted.

A reduced graphene oxide (rGO) supported magnetite nanoparticle (nFe3O4) composite (nFe3O4/rGO) was synthesized and shown for the first time to be an efficient persulfate activator to generate SO4− for trichloroethylene (TCE) degradation. The degradation efficiency of TCE (0.15 mmol L−1) was 98.6% within 5 min in the presence of 6.94 g L−1 nFe3O4/rGO with an optimum mass ratio of 1:4 and persulfate concentration of 3.0 mmol L−1. By dispersing nFe3O4 on the rGO surface, nanoparticle agglomeration was prevented and the aggregation of the rGO sheets was disrupted. Both the redox effect coupled in nFe3O4 and the electron transfer by functional groups containing oxygen on the surface of rGO enhanced the SO4−generation. Given the identified free radical species and the characterization of the nFe3O4/rGO, a persulfate activation mechanism by nFe3O4/rGO for the degradation of TCE was interpreted.

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