Table 1.

Water contact angles and surface roughness of the samples

Sample	Contact angle (°)	Roughness (nm)
Ti	76.0±4.0	8.0±3.5
air-TNTs	33.2±3.2	45.8±4.4
H2-TNTs	3.0±1.0	47.6±6.2

Note: Data are expressed as mean ± SD.

Abbreviations: Ti, titanium; air-TNTs, air-annealed TiO₂ nanotubes; H₂-TNTs, hydrogenated air-TNTs.