Development and testing of thin photocatalyst films

This thesis details the development of surface-exposed nanoparticle (SEN) films made from titanium dioxide (TiO₂) and cadmium sulfide (CdS) nanoparticles, as well as their characterisation and testing for photocatalytic activity by using a variety of known photocatalytic reactions and techniques.<br><br>A TiO₂-SEN film is detailed, based on the formation of ion-pairs formed between TiO₂ P25 nanoparticles in an acidic dispersion, and an anionic lipophilic promoter, which find themselves most stable in a water-organic interface.

These interfacial films are then captured in situ by polymer film formation as the solvent evaporates. The photoactivity of the film is then quantified using the oxidations of 4-chlorophenol and methylene blue, as well as the reductions of methylene blue and resazurin, in solution and ink forms. The photoactivity of TiO₂-SEN film is measured against Pilkington Activ™ glass for each of these reactions, which is a commercial product that has a TiO₂ film analogous to the films made in this work.<br><br>A SEN film from a synthesised CdS colloid is also described, highlighting the ease and versatility of the film synthesis method.