Abstract：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.
