Figure 1
Photosynthesis of β-Bi2O3 thin films.
(a) Scheme of the photochemical process of preparation of crystalline Bi2O3 thin films from UV-absorbing Bi(III) solutions containing a Bi(III)-N-methyldiethanolamine coordination complex with a maximum of light absorption at λ ~ 250 nm (synthesis of solutions is shown in Figure S2). (b) The photoreaction produced in the gel layers derived from the former precursor solutions by the irradiation with UV-light is followed by the decrease of the integrated area of the ν(C–H) stretching vibrations ascribed to the C-H groups (ν(C–H)O ~ 2960 nm, ν(C–H)CO ~ 2900 nm and ν(C–H)N ~ 2860 nm), as a function of the irradiation time at 250 °C in an oxygen atmosphere (graphic at the top). The evolution of the crystallinity of the former layers with the irradiation time at 250 °C, and with a further treatment at 350 °C was followed by X-ray diffraction (graphic at the bottom).
