Vacuum ultraviolet photocatalytic degradation of formaldehyde and ozone decomposition by Au/TiO2 nanocomposite film.

To increase VUV (vacuum ultraviolet) photocatalytic efficiency for removing formaldehyde and decomposing its byproduct,i.e.ozone (O3),Au nanoparticles was supported on TiO2 nanocomposite film with low-temperature adsorption method.Three methods,i.e.UV254nm photocatalysis (TiO2/UV),VUV photolysis (VUV) and VUV photocatalysis (TiO2/VUV) were compared to degrade low concentration formaldehyde in the gas phase.The results showed that the removal ratio of formaldehyde in the TiO2/VUV process was much higher than that in the TiO2/UV or VUV photolysis process.Deposition of Au nanoparticles on TiO2 significantly improved the separation of photogenerated electrons and holes.Accordingly,in the VUV photocatalysis,Au/TiO2 not only increased the removal ratio of formaldehyde,but also significantly decomposed ozone.The concentration of residual O3 was decreased 32%.Moreover,Au/TiO2 film was stable in the VUV photocatalysis process.