Efficient catalytic degradation of bisphenol A by novel Fe0- vermiculite composite in photo-Fenton system: Mechanism and effect of iron oxide shell

Novel Fe0-vermiculite (Fe-Ver-C-H2) composite was synthesized by thermal reduction and acted as catalysts to remove bisphenol A (BPA) in photo-Fenton system. In term of activation ability toward H2O2, separation ability and stability, Fe-Ver-C-H2 presented obvious advantages over other kinds of Fe0-vermiculite composite (Fe-Ver-NaBH4), which obtained by traditional liquid reduction. The reason was that iron oxide shells on the surface of Fe0 were α-Fe2O3 and Fe3O4 for Fe-Ver-NaBH4 and Fe-Ver-C-H2, respectively. And for Fe-Ver-C-H2, the synergistic effect between iron core (Fe0) and iron oxide shell (Fe3O4) is beneficial to catalytic performance. The mechanism and plausible pathway of BPA degradation were also proposed according to the results of radical scavenger studies and gas chromatography-mass spectrometry (GC-MS), respectively. In addition, factorial effects for Fe-Ver-C-H2 in photo-Fenton system were also investigated and optimized as: pH of 5, dosage of 0.2 g L−1 and H2O2 concentration of 20 mM. This study presented a facile method to synthesize novel Fe0-vermiculite composite and provided a new sight to investigate the effect of iron oxide shell on the catalytic performance when Fe0-vermiculite composite acted as catalyst to remove contaminants from the environment in photo-Fenton system.