Photocatalytically Active Polyelectrolyte/ Nanoparticle Films for the Elimination of a Model Odorous Gas a Dariya Dontsova, Vale ´rie Keller,* Nicolas Keller, Pascal Steffanut, Olivier Fe ´lix, Gero Decher* Introduction The past years have brought an increasing number of applications of layer-by-layer (LbL) assembly (e.g., [1,2] ) in a large variety of different fields (e.g., [3–13] ) including catalysis (e.g., [14–24] ), but materials and devices based on large-area LbL-coatings are still scarce. Photocatalytic applications are an especially promising area for LbL- assembly because multilayer films are often transparent, because of the large choice of catalytical components that can be used for their construction and because of the ease by which even porous materials and surfaces such as membranes, textiles, and paper can be coated fairly well from aqueous solutions or dispersions. Some of the recent investigations of LbL-coatings in this field concern heterogeneous photocatalytic oxidation (PCO) Communication Dr. V. Keller, Dr. N. Keller Laboratoire des Mate ´riaux, Surfaces et Proce ´de ´s pour la Catalyse, CNRS UMR 7515, Universite ´ de Strasbourg, 25 rue Becquerel, F-67087 Strasbourg, France E-mail: vkeller@chimie.u-strasbg.fr Prof. G. Decher Institut Charles Sadron, CNRS UPR 22, 23 rue du Loess, F-67034 Strasbourg, France E-mail: decher@ics.u-strasbg.fr Prof. G. Decher Faculte ´ de Chimie, Universite ´ de Strasbourg, 1 rue Blaise Pascal, F-67008, Strasbourg, France a Supporting Information for this article is available from the Wiley Online Library or from the author. Prof. G. Decher International Center for Frontier Research in Chemistry, 8 alle ´e Gaspard Monge, F-67083 Strasbourg, France Prof. G. Decher Institut Universitaire de France, 103 Boulevard Saint-Michel, F-75005 Paris, France Dr. D. Dontsova, Dr. O. Fe ´lix Institut Charles Sadron, CNRS UPR 22, 23 rue du Loess, F-67034 Strasbourg, France Dr. P. Steffanut Clariant Produkte (Schweiz) AG, Rothausstrasse 61, CH-4132 Muttenz, Switzerland Virtually transparent films of Aeroxide TiO 2 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. Macromol. Rapid Commun. 2011, 32, 1145–1149 ß 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com DOI: 10.1002/marc.201100192 1145