Figure 2

taken from the area of the tube only marked by the blue box. A more detailed analysis of the TEM micrographs (Figure S2 in ESI) showed tubular cavities with diameters in the range of 9–11 nm as well as difference in thicknesses of opposite walls of the tubes). (d) Thermogravimetric analysis of T1.
T1 TEM micrographs of sample T1 at different magnifications (a, b) in a JEOL JEM-2011 operated at 200 kV, schematic drawing of the structure of H2Ti3O7 NTs (inset in a), and (c) in a TALOS G-2 TEM at 200 kV. The inset is a Fourier transform