Synthesis of nanocrystalline marcasite iron ditelluride FeTe2 in aqueous solution

Reaction of an alkaline aqueous solution dissolving elemental tellurium and iron(II) complex Na2[Fe(EDTA)] aqueous solution produces nanocrystalline marcasite FeTe2 at 140°C under atmospheric pressure. All peaks in the XRD pattern of the final product can be indexed to orthorhombic FeTe2 with the cell constants a=5.31 إ, b=6.29 إ and c=3.86 إ. TEM image of FeTe2 nanocrystallites shows an average particle size of 25 nm with a spherical morphology. The tellurium alkaline solution, as a tellurium source, makes FeTe2 crystallize well in aqueous solution. The use of iron(II) complex instead of iron(II) ion greatly reduced the amount of byproduct. The mechanism of the formation of iron ditelluride was discussed.