Surface modification of titania-coated cobalt ferrite magnetic photocatalyst by cold plasma

摘要

Titania-coated cobalt ferrite (TiO_2/CoFe_2O_4) magnetic nano-photocatalysts were prepared by the hydrolysis of titanium tetrachloride in the presence of the CoFe_2O_4 magnetic particles. The photocatalysts were then modified by Ar, N_2, and air plasmas. The crystal structures of the samples were characterized by X-ray diffraction. The active species in the plasma space were detected by optical emission spectroscopy (OES). The photocatalytic activities of the samples were evaluated by the photocatalytic degradation of methyl orange solution. The results indicated that the crystal structure of TiO_2/CoFe_2O_4 was good, and that TiO_2 exists in anatase and rutile forms. The photocatalytic activity of the sample modified by air plasma was higher than of that modified by N_2 and Ar plasmas. The OES analyses of Ar, N_2, and air plasmas confirmed that O active species played important roles in improving photocatalytic activity in the process of TiO_2/CoFe_2O_4 modification by cold plasma.