Gas-Supported High-Photoactivity TiO₂ Nanotubes

Figure 5

TEM images of (a), (b), and (c) TiO₂-NTs@@SiO₂ with “open-ended” structure (650°C, 2 h). (d) TiO₂-NRs@@SiO₂ with “close-ended” structure (700°C, 2 h).

(a)

(b)

(c)

(d)