Ionic Liquid Assisted Exfoliation of Layered Magnesium Diboride

Abstract

The discovery of graphene showcased anability to isolate atomic thin sheet from layered graphite, and presented a precedent to the scientific community for exploring a similar possibility in other layered materials. Magnesium diboride (MgB2), which has metal atoms sandwiched in between boron honeycomb planes, represents an ionic layered material isostructural to intercalated graphite. We show that ultrasonication of MgB2 in ionic liquid (1-butyl-3-methyl imidazolium tetrafluoroborate)results in a stable dispersion of few-layer-thick boron based nanosheets. Furthermore, these nanosheets (∼3-6 µm wide, ∼2 nm thick) are found to exhibit an optical band-gap of ∼3.3eV alongwith excitation wavelength dependent photoluminescence.