Highly efficient and recyclable catalyst: porous FeO-Au magnetic nanocomposites with tailored synthesis.

In this work, we reported the tailored design of highly efficient FeO-Au magnetic nanocomposite (MNP) catalysts. FeO nanocrystals with three different morphologies have been developed with engineered amounts of urea, and the plausible mechanism has been proposed. Then by controlling the amount of Au seeds, FeO-Au MNPs with different morphologies and tunable Au deposition have been realized. Characterizations including x-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectra, and elemental mapping are implemented to unveil the structural and physical characteristics of the successfully developed FeO-Au MNPs with different morphologies. The catalytic ability of FeO-Au MNPs with different morphologies have been compared by applying them to degrading RhB and 4-NP, meanwhile the correlation between the amount of Au seeds and the turnover frequency as well as the catalytic ability of FeO-Au MNPs is investigated systematically. We found that the flower-like FeO-Au MNPs with 20 ml Au seeds added achieved the best degradation efficiency of 96.7%, and their catalytic ability were almost unchanged after recycling. Out study sheds the light into the tailored design of highly efficient and recyclable catalysts for RhB and 4-NP.