413692.fig.005a
(a)
413692.fig.005b
(b)
413692.fig.005c
(c)
413692.fig.005d
(d)
Figure 5: TEM images of carbon-coated TiO2 nanofibers (a)–(d) calcined in air for 3 h at 400, 600, 800, and 1,000°C, respectively.