Titanium oxide-based 1D nanofilaments, 2D sheets, and mesoporous particles: Synthesis, characterization, and ion intercalation

In this work, we report on the large-scale synthesis of TiO2-based one-dimensional (1 D) nanofilaments (NFs) using a facile, bottom -up, one-pot, solution-processing synthesis protocol. Our method en-tails mixing TiB2 commercial powders with tetramethylammonium-hydroxide (TMAH) in plastic bottles at 80 degrees C for a few days under ambient pressure. The resulting lepidocrocite titania-based 1D NFs, with ? 537 A2 cross-sections self-assemble in a plethora of nanostructures that depend on solvent used for washing. In ethanol, they form mesoporous particles that are free flowing, and nearly spherical, with an average diameter in the z13 mm range. In water, they self-assemble into pseudo-two-dimensional flakes comprised of nanobundles. The formation of the NFs occurs at the TiB2/reaction reagent interface allowing for the formation of core-shell configura-tions. The intercalating TMA+ cations between the NFs can be readily exchanged with H3O+, Li+, Na+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, or Zn2+ cations. With zeta-potential values of z -50 mV, the resulting materials form quite stable colloids in water.