Nb-Doped TiO₂ Photocatalysts Used to Reduction of CO₂ to Methanol

Figure 9

XPS spectra of Nb–TiO₂ 2.5% Nb (w/w) photocatalyst: (a) Ti_2p peaks and (b) NbO_{2 3d3/2} NbO_{2 3d5/2} peaks.

(a)

(b)