Fig. 3From: Sol-gel Synthesis, Photo- and Electrocatalytic Properties of Mesoporous TiO2 Modified with Transition Metal IonsDiffuse reflectance spectra of the powders prepared from the films precursors: TiO2 (1) and TiO2 doped with 5% Co (2), Ni (3), Mn (4), and Cu (5) calcined at 450 (a) and 650 °C (b)Back to article page