The Synergistic Effect of Nitrogen Dopant and Calcination Temperature on the Visible-Light-Induced Photoactivity of N-Doped TiO₂

Figure 4

TEM images of N-TiO₂ prepared (a)–(e) at various calcination temperatures with 2.0 ammonia/TTIP ratio and (f) the selected area electron diffraction of A20T4.

(a)

(b)

(c)

(d)

(e)

(f)