Three-dimensional hierarchical Pt-Cu superstructures

Three-dimensional (3D) hierarchical Pt-Cu tetragonal, highly branched, and dendritic superstructures have been synthesized by a facile template-free hydrothermal approach, showing growth patterns along (111, 110), (111), and (100) planes, respectively. These structures have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), inductively coupled plasma optical emission spectrometry (ICP-OES) and a detailed formation mechanism has been developed, which shows that the in situ formed I₂ and the galvanic replacement reaction between Cu and Pt⁴⁺ may guide the formation of these superstructures. The comparative electrocatalytic properties have been investigated for methanol and ethanol oxidation. Due to their interconnected arms, sufficient absorption sites, and exposed surfaces, these superstructures exhibit enhanced electrocatalytic performance for electro-oxidation of methanol and ethanol when compared with commercial Pt/C and Pt black.