Synthesis of large monolayer titania nanosheets through flux method

Herein, we present the structural and electrical properties of layered titanate, the precursor of an ideal two-dimensional (2D) nanosheet. A K0.8Ti1.73Li0.27O4 (KTLO) sample was synthesized by the flux method to maximize the area of the, relative to that under conventional methods, and to assess the oriented growth direction of the synthesis process. The structure of the protonated layered titanate H1.07Ti1.73O4 (HTO), obtained by replacing the intercalated K+ cations with H3O+, was analyzed to observe the effect of variables in the acid exchange process. Notably, the electrical characteristics of both layered titanates in the bulk state have not been previously reported. Herein, we measured the dielectric permittivity of bulk layered titanates without thermal treatment, which was observed to be lower than that of the nanosheet form. Additionally, these titanates were successfully exfoliated into large single-layer nanosheets. Overall, these results provide insights to clarify the properties of layered materials prior to nanosheet exfoliation.