Size control and shape evolution of single-twinned platinum nanocrystals in a room temperature colloidal synthesis

作者：Osmic Milena^*; Kolny Olesiak Joanna; Al Shamery Katharina

来源：CrystEngComm, 2014, 16(42): 9907-9914.

DOI：10.1039/c4ce01342e

Platinum nanocrystals in the size range of a few nanometers are especially interesting candidates for catalytic applications. We present an easy, low-temperature procedure, which allows for a precise size control of this material. Uniform platinum nanoparticles were obtained by reduction of platinum.IV) chloride with tetrabutylammonium borohydride in toluene solution at room temperature. Dodecylamine served as a ligand. The size of the resulting particles could be controlled in the range between 2 and 5 nm by slow addition of platinum monomers and the reducing agent to preformed 2 nm seeds. Furthermore, particles with a tetrapod shape could be synthesized. In contrast to the usual kinetic control leading to the formation of elongated structures, the analysis of the growth process of the tetrapods suggests a reactioncontrolled growth process. Their structure was investigated by powder X-ray diffraction and highresolution electron microscopy, which revealed that two branches of the tetrapods grow along the %26lt; 111 %26gt; direction, while the other two show growth in the %26lt; 220 %26gt; direction. This uncommon shape of the tetrapods is attributable to the presence of a twin defect parallel to the %26lt; 220 %26gt; direction. Thus, the method presented in the article allows for the formation of platinum particles with a single twin defect with a high yield.

• 出版日期2014