Photocatalytically Active Polyelectrolyte/Nanoparticle Films for the Elimination of a Model Odorous Gas

Virtually transparent films of Aeroxide TiO2 P25 were fabricated via layer‐by‐layer assembly with sodium poly(styrene sulfonate). Nanoscale films are formed on model surfaces for characterization or inside of cylindrical reactors for investigating the catalytic properties. Films are fairly homogeneous and smooth over large areas and show different optical interference colors depending on film thickness. The application‐relevant photocatalytic performance of such films toward on‐flow degradation of hydrogen sulfide under UV‐A irradiation was investigated. Scanning electron microscopy reveals a nanoporous structure allowing for the permeation of gas. Consequently, the catalytic efficiency of the films increases with increasing film thickness retaining a considerable activity of the corresponding nanoparticle powder. Scheme 1 depicts in a general way the functionalized reactor and the principle of the measurement. High quality homogeneous and optically transparent poly(styrene sulfonate)/titanium dioxide multilayer films are assembled on large surface areas. The nanoporous structure of such films permits access of the pollutant to catalyst surface. The photocatalytic activity of these LbL films is illustrated for the decomposition of hydrogen sulfide flow under UV‐A irradiation, and compared to the activity of the original TiO2 powder.