Superior Visible-Light Driven Photocatalyst of Ni-Doped CdFe2O4 for Environmental Pollutants Degradation

A series of magnetic Ni doped CdFe2O4 hybrids (Ni-CdFe2O4) were prepared successfully through deposition–calcination method and characterized by XRD, TEM, SEM, EDS, Raman, BET, XPS, VSM and DRS. Under visible light irradiation, the photocatalytic properties of Ni-CdFe2O4 were investigated towards degradation of antibiotics tetracycline and dye pollutants (such as Malachite green and Congo red). Depending on molar ratios of Ni to CdFe2O4, the degradation efficiencies decreased in the following order: 2%Ni-CdFe2O4 > 5%Ni-CdFe2O4 > 1%Ni-CdFe2O4 > CdFe2O4. Possible photocatalytic mechanism was speculated based on the photocatalytic degradation properties of the Ni-CdFe2O4 hybrid. Ni-doping improved the optical absorption in visible region and the specific surface area of Ni-CdFe2O4 increased, which resulted in narrowing bandgap and increasing the visible-light absorption compared with CdFe2O4 nanoparticles, whereas the recombination of electron-hole pairs reduced. Meanwhile, Ni-CdFe2O4 could be easily separated from the reaction system because of its magnetism. For its splendid photocatalytic ability, Ni-CdFe2O4 has a great potential on remedying environmental pollutants.