Nitrogen-Doped TiO₂ Nanotube Arrays with Enhanced Photoelectrochemical Property

Figure 6

XPS spectra of the N-doped TNT arrays sample. (a) A survey spectrum, (b) a spectrum of Ti 2p, (c) a spectrum of O 1s, and (d) a spectrum of N 1s. The doping conditions are that reaction voltage is 3 V, reaction time 3 h and electrolyte concentration 0.5 M.

(a)

(b)

(c)

(d)