Probing edge-activated resonant Raman scattering from mechanically exfoliated 2D MoO ₃ nanolayers

Abstract

We report spatially resolved vibrational analysis of mechanically exfoliated single-crystalline α-MoO3 nanolayers. Raman scattering from α-MoO3 was enhanced predominantly at the outside edges of the nanolayers. The enhanced Raman scattering at the edges was attributed primarily to the enhanced resonant Raman effect caused by a high density of oxygen vacancies localized at the edges. The localized vacancy sites corresponded to a non-stoichiometric phase of MoO3, which would provide reactive sites with high catalytic activity.