Funct. Mater. 2022; 29 (1): 62-71.

Composite materials containing copper-zinc ferrites (FC) were obtained by coprecipitation from spent technological sulfate copper-zinc solutions. The ratio of copper, zinc and iron in ferrites has been determined. Zinc is more fully included in ternary ferrites than copper. It has been proven that the surface groups of ferrites are O-H in adsorbed associates and end groups of water; bending vibrations of the Zn-O-H, Fe-O-H and O-H groups have been recorded. The specific saturation magnetization of ferrite particles varies in the range of 6-46 emu/g decreasing with an increase in the proportion of nonmagnetic Zn and Cu. There is no residual magnetization in ferrites. The synthesized ferrites belong to superparamagnets with a particle size of 7-14 nm. FCs are active in the processes of purification of the aqueous phase from the dye methyl violet (MV). For most FCs, purification is effective when the mass of ferrite exceeds the mass of MV by a factor of 1000, when high purification efficiency and the degree of MV conversion per unit mass of FC are simultaneously achieved. Within 5 hours the solutions can be purified from MV by 99 %. Simultaneous photocatalysis and adsorption is possible. The photocatalytic activity of FCs manifests itself at the beginning of the process, with a further decrease when the FC surface is screened by the MV layer.