H+ intercalation into molybdenum oxide nanosheets under AFM tip bias

The local hydrogen ions intercalation behavior in α-MoO3 nanoflakes is explored under the electric field of an atomic force microscopy (AFM) tip. Protons are excited by AFM tip bias-induced electrolyzation of absorbed water molecules on the surface of α-MoO3 nanosheets in ambient environment, and then intercalated into α-MoO3 lattice. The formed HxMoO3 is shown to have a 0.2 eV reduction in the bandgap and also altered electric behaviors and surface morphologies. This research provides a unique approach for understanding the relationship between nanoscale hydrogen intercalation and the surface morphology and bandgap of two-dimensional (2D) α-MoO3 nanosheets. This investigation of ionic intercalation in 2D-layered materials will help in future nanoscale engineering of batteries, electrochromism, photocatalysis, and supercapacitors.