Facile preparation of nanostructured NixZn1−xFe2O4/CNTs composites with enhanced visible-light-driven photocatalytic activity for tetracycline degradation

NixZn1−xFe2O4/CNTs composite photocatalysts were prepared via a facile hydrothermal method, and their physical and chemical properties were investigated. The effect of different Ni doping amounts on the photocatalytic activity of NixZn1−xFe2O4 and Ni0.5Zn0.5Fe2O4/CNTs photocatalysts containing different amounts of carbon nanotubes (CNTs) were investigated for their ability to degrade tetracycline (TC) in wastewater. The results showed that Ni0.5Zn0.5Fe2O4/CNTs (5% CNTs) had the highest photocatalytic activity, achieving a TC degradation of 96%. The origin of the excellent performance of the photocatalysts, as well as the photodegradation mechanism, were also discussed. Effective electron–hole separation is believed to be responsible for the significantly improved photocatalytic activity. After four photocatalytic degradation experiments, the composite photocatalyst retained its high photocatalytic activity, and the results showed that the composite photocatalysts were highly stable and could be magnetically separated.