Photoelectrocatalytic Degradation of Humic Acids Using Codoped TiO₂ Film Electrodes under Visible Light

Figure 5

FESEM images of ((a) and (b)) view of pure TiO₂ film and ((c) and (d)) top view of Cu/N codoped TiO₂ film.

(a)

(b)

(c)

(d)