The conventional temperature‐induced polyol synthesis of platinum nanoparticles is a powerful and well‐established method for the preparation of stable, surfactant‐free platinum nanoparticles (Pt NPs) with controlled shape, size and size distribution. Recently, we reported that exposure to daylight leads to the formation of Pt NPs from precursor solutions, suggesting that a parallel approach of UV‐induced polyol synthesis could be a cheaper and more widely applicable alternative. Here we report a controlled size and size distribution for Pt NPs prepared using UV irradiation instead of thermal treatment. Results demonstrate that, depending on the concentration of NaOH in the reaction mixture, the size of produced nanoparticles can vary between 1 and 5.8 nm. We also show, for the first time, how NaOH affects the formation of organic side products, which alters Pt NPs stability, and demonstrate a method for the preparation of stable nanoparticle suspensions with an average particle size of 5.8 nm.

,I dunnP restholm, IlirianaQ oqaj, ChristinaB.R iel, To bias V. Rostgaard, Nora Saleh, HannibalM.S chultz, Mark Standland,Jens S. Svenningsen, RasmusTruels Sørensen, JesperV isby,E milie L. Wolff-Sneedorff, Malte Hee Zachariassen, Edmond A. Ziari, Henning O. Sørensen, and Thomas Just Sørensen* [a] To Professor Klaus Bechgaard and Professor ThomasB jørnholm for always teaching to think outside the box Abstract: Ionic self-assembly (ISA) is ap rovenm ethod that exploits non-covalenti nteractions to generate supramolecular materials. Here, we have expanded the scope of this approach fabricating thin films with nanoscopic order maintained over centimeters. Cationiclayers of benzalkonium surfactants form al amellar template. The template is able to host layers of negatively charged polyaromatic functional units, hered emonstrated with b-naphthol-derived azo-dyes. We show that av arietyo ft hese functional building blocks can be incorporated in the lamellar templatet hrough ISA. Sixteen different materials were produced,c haracterized, and processedi nto thin films, with lamellar order perpendicular to the substrate. Thus, ad esign concept is demonstrated in which diverse functional motifs can be isolated and ordered in a2 Dl attice between layers of alkyl chains in bulk and in thin films, in which the molecular orderi sm aintained and alignedt othe substrate.

Self‐Assembly. Self‐organizing materials allow for fabrication of functional nanostructures. A two‐component approach to self‐assembled nanostructures has been developed, which allows for simple preparation of thin films with lamellar molecular order. The nanoscale molecular order is maintained over centimeters and is a direct result of the tailored chemical properties of the materials. Furthermore, the two‐component approach allows for different functions to be incorporated in the thin films. For more information, see the Full Paper on page 253 by Thomas Just Sørensen and co‐workers, which is featured on the back cover. Cover image kindly provided by Merlin von Soosten.