Combinatorial aerosol assisted chemical vapour deposition of a photocatalytic mixed SnO2/TiO2 thin film

Combinatorial Aerosol Assisted Chemical Vapour Deposition (cAACVD) was used to grow a thin film that graduated across its width from tin dioxide to titanium dioxide. This is a relatively new technique that can be used to create a variety of mixed phase and composition thin films on a single substrate. Here cAACVD was used to deposit a mixed phase TiO2 and SnO2 film and composition was related to UV photocatalysis, hydrophobicity and microstructure not inherent to anatase TiO2 or cassiterite SnO2. Characterisation was achieved using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy. Functional testing to elucidate the differences in functional properties across the film was undertaken by the photo-induced degradation of a resazurin ‘intelligent’ ink, a photo-induced wettability study and two-point resistivity measurements. Functional properties showed enhanced photocatalysis in comparison to Pilkington Activ™ with similar formal quantum yield (molecules destroyed per absorbed photon) and formal quantum efficiency (molecules destroyed per incident photon) values.