621254.fig.004a
(a)
621254.fig.004b
(b)
621254.fig.004c
(c)
621254.fig.004d
(d)
Figure 4: SEM images of as-obtained BiVO4 as the function of hydrothermal reaction time at pH 7 and temperature 195°C: (a) 2 h, (b) 6 h, and (c) 16 h; (d) TEM image of (b).