Magnetically separable photocatalytic composite γ-Fe2O3@TiO2 synthesized by heterogeneous precipitation

Synthesis of magnetically separable photocatalytic active composite γ-Fe2O3@TiO2 is the main objective of this work. In the first step, maghemite nanoparticles were prepared by a precipitation method and consequently covered by the citric acid in order to adjust the zeta-potential of the particle surface. The magnetic carrier was enfolded by TiO2 via heterogeneous precipitation of TiOSO4 using urea as a precipitation agent. The procedure was designed to minimize the production costs in order to be easily transferred into the industry scale conserving the high quality of the photoactive product. Nontoxic element oxides were used because of the ecological acceptance. Various methods were employed to characterize and study the intermediate (magnetic nanoparticles) and final materials (TiO2-maghemite composite), respectively. Moreover, the influence of the subsequent annealing on the structure, phase composition and properties of the products is discussed.