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Pure perovskite compound SrFeO 3 nanocrystals were successfully synthesized in molten NaNO 3 KNO 3 eutectic with Na 2 O 2 from a mixture of strontium nitrate and ferric nitrate. The effect of metal precursors, salt medium, annealing temperature (mainly 400800°C), and oxidizing properties of the melt on the phase composition, crystallite size and morphology of the resulting metal oxides were systematically studied by simultaneous TG/DSC, X-ray diffraction (XRD), scanning electron microscopy (SEM) methods. The results showed that the formation of the SrFeO 3 phase mainly depended on the nature of the metal precursor and salt medium. It was found that metal nitrates are the suitable precursors and NaNO 3 KNO 3 eutectic with Na 2 O 2 is the suitable salt medium, which results in the formation of pure SrFeO 3 nanocrystals at a much lower temperature of 400°C.

Well-dispersed zinc ferrite (ZnFe 2 O 4 ) nanoparticles were successfully prepared by a novel salt-assisted solution combustion process. The effects of types and amounts of the added salt on the properties of the products were investigated by XRD, SEM, and BET nitrogen adsorption techniques. The results indicated that the introduction of salt into reaction system facilitate the formation of well-dispersed spinel zinc ferrite and increase specific surface area of the resultants from 7.14 to 88.34 m 2 ·g ¹1 when KCl/M ratio is 2/3. A visible-light-active ZnFe 2 O 4 /TiO 2 photocatalyst was prepared by physically grinding the ZnFe 2 O 4 nanoparticles with TiO 2 (P25) at ambient temperature, and it exhibited excellent photocatalytic activity for the mineralization of rhodamine B. With increasing of ZnFe 2 O 4 amount from 0 to 3wt %, the activity of ZnFe 2 O 4 /TiO 2 composite increased. The maximum photoactivity is observed when the amount of ZnFe 2 O 4 is 3 wt % and more than 97% of rhodamine B disappears after 4 h visible-light irradiation.