Photocatalytic Activity under Simulated Sunlight of Bi-Modified TiO₂ Thin Films Obtained by Sol Gel

Figure 8

XPS spectra evolution of O 1s region as a function of bismuth content, (a) 0, (b) 0.5, (c) 4.9, (d) 10.4, (e) 21.5, and (f) 25.4 at. %.