Adsorption and photocatalytic and photosensitised bleaching of acid orange 7 on multilayer mesoporous films of TiO2

► Mesoporous titania films of different thicknesses are prepared. ► Film characterisation includes: surface area, amount of adsorbed dye (AO7) and photocatalytic and dye-photosensitised activities. ► The amount of adsorbed dye depends directly upon film surface area and can be used to calculate the same. ► The two different photoactivities depend directly upon the film surface area. ► Quantum efficiencies for the photocatalytic and dye-photosensitised processes are: 0.08 and 0.01%, respectively.