Pt Nanoparticles Surfactant‐Directed Assembled into Colloidal Spheres and used as Substrates in Forming Pt Nanorods and Nanowires

Platinum nanoparticles were synthesized via polyol reduction and then assembled into colloidal spheres under the direction of an organic surfactant such as sodium dodecyl sulfate. These spheres serve as substrates to form Pt nanorods and nanowires with controllable lengths, depending on the amount of Pt precursor added in a subsequent step in the presence of Fe2+ or Fe3+ ions. Uniform Pt nanowires (5 nm in diameter and over 500 nm in length: see image) are prepared using this procedure.