Protonic titanate derived from CsxTi2-x/2Mgx/2O4 (x=0.7) with lepidocrocite- type layered structure

A layered titanate CsxTi2-x/2Mgx/2O4 (x = 0.7) with lepidocrocite (gamma-FeOOH)-type layered structure was prepared via solid-state reaction. Extraction of both Mg2+ ions in the host layers and interlayer Cs+ ions was achieved during an acid-exchange process, producing a new protonic titanate HxTi2-x/2O4-x/2 center dot H2O. This phase was distinguished from isomorphous related compounds in terms of removable lattice Mg and O atoms. The protonic titanate HxTi2-x/2O4-x/2 center dot H2O showed excellent exfoliation/delamination reactivity upon intercalating organic amine ions as well as the ability to produce single two-dimensional titanate nanosheets with small thickness of about 1 nm. These findings offered a new clue for understanding the physicochemical properties of lattice dopants in lepidocrocite titanates.