Exceptional properties of metal nanoparticles present many opportunities for applications in numerous fields such as catalysis, medicine, electronics, optics. Consequently, much effort has been devoted to the production of nanoparticles in a controlled manner and to increase the production yield in a cost-effective manner. Still, the systematic production of uniform small metal nanoparticles poses a long-standing challenge.
We will report on a general approach for the controlled, high yield synthesis of small and uniform metal nanoparticles in dense microemulsions. Anionic (Na-AOT), cationic (DDAB) and non-ionic (Triton X-100 and Brij-35) were used to produce nanoparticles of different size. By using various types of surfactants, we demonstrate the generality of our approach. It enables us to extend the control over the size, uniformity of nanoparticles and the timescale of the synthesis procedure, compared to the limiting single template system. The approach consists of four crucial steps: (a) selection of a surfactant, (b) study of a phase diagram and selection of suitable microemulsion compositions, (c) synthesis and (d) extraction of the nanoparticles.
As a result metal, nanoparticles (such as Pt and Au) with a size range from 2.4 to 6.2 nm were produced. The size and monodispersity was controlled by the surfactant packing parameter. Platinum nanoparticles were harvested on carbon support and tested as a catalyst material in Proton Exchange Membrane Fuel Cell (PEMFC) and showed high activity and excellent durability.
g.j.m.koper@tudelft.nl
