Iron sulfide (FeS) nanotubes using sulfurization of hematite nanowires.

We report the phase transformation of hematite (α-Fe2O3) single crystal nanowires to crystalline FeS nanotubes using sulfurization with H2S gas at relatively low temperatures. Characterization indicates that phase pure hexagonal FeS nanotubes were formed. Time-series sulfurization experiments suggest epitaxial growth of FeS as a shell layer on hematite. This is the first report of hollow, crystalline FeS nanotubes with NiAs structure and also on the Kirkendall effect in solid-gas reactions with nanowires involving sulfurization.