Enhanced Photocatalytic Degradation of 17α-Ethinylestradiol Exhibited by Multifunctional ZnFe2 O4 -Ag/rGO Nanocomposite Under Visible Light.

In this paper, ZnFe2 O4 , a visible light active photocatalyst, was comodified by graphene oxide (GO) and Ag nanoparticles (NPs) to form ZnFe2 O4 -Ag/rGO nanocomposite (NC) by facile one-pot hydrothermal method. Reduction of GO and formation of ZnFe2 O4 and Ag nanoparticles occurred simultaneously during hydrothermal reaction. The photocatalytic activity of the NC was investigated under visible light, for the degradation of 17α-ethinylestradiol (EE2), a nondye compound, which also is an emerging pollutant with endocrine-disrupting activity. The pseudo rate constant (k') of as-synthesized ZnFe2 O4 -Ag/rGO NC was higher by the factor of 14.6 and 5.6 times than the corresponding ZnFe2 O4 and ZnFe2 O4 /rGO respectively. The synergistic interactions between ZnFe2 O4 , Ag and rGO leading to decreased aggregation of the NPs, increased surface area, better absorption in visible region, effective electron-hole generation transfer. However, in the presence of humic acid (HA), the photosensitization effect was predominated by competitive interaction resulting in only 80% removal of EE2 within the same time. Moreover, the composite can easily be magnetically separated for reuse.