Delithation, Exfoliation, and Transformation of Rock-Salt-Structured Li2TiO3 to Highly Exposed {010}-Faceted Anatase

{010}-Facet-exposed anatase TiO2 crystals exhibit the highest photoreactivity among the exposed facets. To obtain a higher exposure rate of this facet, the work investigated the transformation of the nanosheets with cavities within the layers derived from a rock-salt-structured Li2TiO3 precursor. All the lithium ions were extracted from the precursor by H+/Li+ ion exchange in HCl aqueous solutions, and after tetramethylammonium ions were intercalated, the precursor can delaminated into the nanosheets. The [TiO3]2- nanosheets were hydrothermally treated under different temperatures and pH values. The results showed that the anatase phase was formed in a wider range of pH and temperature, compared with using nanoribbons of [Ti4O9]2- and nanosheets of [Ti1.73O4]1.07-. At low pH, [111]-faceted nanorod-shaped anatase nanocrystals were formed preferentially, and the nanocrystals preferentially grow along the [001] direction with the increase of solution pH, leading to a large percentage of {010} facets on their surface. The photocatalytic activity increases with the increase of exposure rate of {010} facets.