(a) High pressure powder x-ray diffraction patterns of TiO₂-B nanoribbons up to 30.9 GPa at room temperature. (b) A comparison between the x-ray patterns of the as-synthesized TiO₂-B nanoribbons obtained at 30.9 GPa and recovered at ambient conditions. Three weak peaks (marked with asterisks) are derived from the energy-dispersive synchrotron x-ray diffraction system. The figure is reproduced from Ref. [21].