Nitrogen-Doped TiO₂ Nanotube Arrays with Enhanced Photoelectrochemical Property

Figure 1

FESEM top images of the (a) undoped and (b) N-doped TNT arrays samples. The doping conditions are that reaction voltage is 3 V, reaction time 3 h, and electrolyte concentration 0.5 M. The insets show the corresponding cross-sectional images.

(a)

(b)