Design of direct Z-scheme superb magnetic nanocomposite photocatalyst Fe3O4/Ag3PO4@Sep for hazardous dye degradation

Z-scheme Fe-3 O-4/Ag-3 PO4 @Sep magnetic nanocomposite photocatalyst was prepared via an eco-friendly coprecipitation approach. Various analytical methods were used to assess the structure, the morphology, and the optical absorption properties of the photocatalyst. The sepiolite as support of Ag-3 PO4 and Fe-3 O-4 nanoparticles, prevented the aggregation and the photo-corrosion of the bare Ag-3 PO4, and enhanced the photocatalytic stability and activity of the photocatalyst by a synergetic effect. Further, the band gap energy of the nanocomposite photocatalyst, as determined from the density functional theory calculations, was reduced, from 2.59 eV for Ag-3 PO4 (1 1 0), and from 2.98 eV for Fe-3 O-4 (2 2 0), to about 2.37 eV for Fe-3 O-4/Ag-3 PO4 @Sep. The obtained dye degradation rate value of 0.480 min(-1), was 69 times superior to pure Fe-3 O-4, 5 times higher than the bare Ag-3 PO4, and 3 times higher than Ag-3 PO4 @Sep. More importantly, Fe-3 O-4/Ag-3 PO4 @Sep shows continuous photocatalytic activity, even after three cycles of reuse.