SEM images of self-organized TiO2 nanotubes with different diameters. The nanotubes are in the range of 15 to 100 nm before (a to d) and after (e to h) the ScCO2 treatment. Disordered Ti(OH)4 precipitates are indicated by white arrows.
Lan et al. Nanoscale Research Letters 2013 8:150 doi:10.1186/1556-276X-8-150