Figure 1

Colour and spectral changes of the photocatalysts. (a, c) Colour changes of the (a) rutile- and (c) anatase-based photocatalyst suspensions after leaving in the dark and under irradiation with simulated solar light. (b) Spectra of the as-prepared photocatalyst suspensions. (d–g) Photographs of the (d, f) rutile- and (e, g) anatase-based photocatalyst coating (d, e) with or (f, g) without white pigments. (h) Spectral changes of the rutile- and anatase-based coatings in the dark and under illumination (fluorescent light, > 380 nm, 500 lx).