Preparation and characterisation of novel thick sol–gel titania film photocatalysts

Abstract

The preparation and characterization of thick (9 µm), clear, mechanically robust and photocatalytically active films of nanocrystalline anatase titania are described. XRD and SEM analysis show the films comprise 13 nm particles of anatase TiO₂. Thin (54 nm) films of the ‘paste’ TiO₂, along with sol–gel titania films made by a more traditional route are also prepared and characterised. All titania films mediate the photocatalytic destruction of stearic acid with a quantum yield of 0.0016 ± 0.0003, using either 365 nm (i.e. BLB) or 254 nm (germicidal) light. P25 TiO₂ films also appear to mediate the same process with a similar formal quantum efficiency. Of all the films tested, the thick paste TiO₂ films are the most ideally suited for use with near UV light, for reasons which are discussed. All the titania films tested exhibit photoinduced superhydrophilicity.