Rapid photodegradation of methyl blue on magnetic Zn1−xCoxFe2O4 nanoparticles synthesized by hydrothermal process

Zinc cobalt ferrite Zn1−xCoxFe2O4 (x = 0-1.0) nanoparticles with magnetic separation ability from photocatalysis system were synthesized by hydrothermal method. Effects of zinc content on the microstructure, surface alkaline-acidic behavior and photocatalytic property of the nanoparticles were studied. The oxidation-reduction potential of the nanoparticles in photocatalysis condition was obviously negative and decreased with the increase in Co content. The photodegradation rate of methyl blue aqueous solution on the nanoparticles increased as the increase of Co content under sunlight. The variations of the oxidation-reduction potential and photocatalytic rate with Co content were discussed on basis of the light absorbance, microstructure, and physicochemical characteristics of the nanoparticles. The ferrite nanoparticles all showed a ferromagnetic behavior with the saturation magnetization of ∼39.7-65.9 emu/g, which can ensure magnetic separable performance of the nanoparticles from the photodegradation systems.