Nitrogen-Doped TiO₂ Nanotube Arrays with Enhanced Photoelectrochemical Property

Figure 2

XRD patterns of (a) the as-prepared TNT arrays sample, (b) the undoped TNT arrays sample annealed at 450°C for 3 h, and (c) N-doped TNT arrays sample after annealing at 450°C for 3 h. The doping conditions are that reaction voltage is 3 V, reaction time 3 h, and electrolyte concentration 0.5 M. 𝐴, 𝑅, and 𝑇 represent anatase, rutile, and titanium, respectively.