ИСТИНА

Zn-​contg. magnetite nanoparticles (NPs) stabilized by a thermally stable polymer, polyphenylquinoxaline, were shown to be efficient magnetically recoverable catalysts for the conversion of syngas to methanol. XPS study showed that the highest activity of the catalyst was achieved when Zn species were intimately distributed within the magnetite NP without substitution of Fe2+ species. Here we demonstrate that the information on the Zn distribution within the Fe3O4 NPs can be obtained from studying fluorescent properties of these NPs. A significant decrease in the fluorescence emission intensity of Zn-​contg. Fe3O4 NPs compared to parent Fe3O4 NPs suggests that the Zn species quench the Fe3O4 emission through fluorescence resonance energy transfer. This distance dependent interaction allows for the detn. of the Zn interactions with the magnetite surface and intercalation into the spinel magnetite structure. In addn., a series of Cr-​doped Zn-​contg. Fe3O4 NPs were also synthesized. The investigation of their fluorescence properties showed a similar behavior.