This work reports the fabrication of hierarchical flowerlike platinum nanostructures (Pt nanoflowers, PtNFs) on a 3-aminopropyltriethoxysilane (APTES) monolayer and their electrocatalytic applications. The obtained PtNFs were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and electrochemical methods. The growth mechanism of the PtNFs may be attributed to the inhomogeneous diffusion of PtCl62- ions on the surface of the electrode. Moreover, it has been found that the PtNFs modified electrodes exhibit excellent electrocatalytic activity for the oxidation of methanol and the reduction of oxygen when compared to conventional Pt nanoparticle modified electrodes. The increased catalytic activity may be a result of the unique morphology of the PtNFs. (C) 2011 Elsevier B.V. All rights reserved.