Two-dimensional TiO2 nanosheets(thickness of~11 up to~80 nm)were successfully synthesized by atomic layer deposition(ALD)with dissolvable polymer layer functionalized as a sacrificial layer.It reveals that the typical thickness of the TiO2 nanosheets that can be achieved are lower than that of the TiO2 film grown onto the planar surface of silicon where numerous reactive sites exist for initial ALD.It has been confirned that the TiO2 nanosheets with fewer ALD cycles are flexible and then transformed to become a stiffsheet by raising of the nanosheets thickness.