An anatase TiO₂ nanosheet array (TNSA) assembled by {116} facet-oriented nanocrystallites with {116} facets parallel to the surface is synthesized directly on a fluorine-doped tin oxide substrate via a two-step process, and exhibits 50% higher photocatalytic activity than {001} facet-oriented TNSA. The precursor and TNSA are both suggested to be grown via the “oriented attachment” mechanism.