Facile Synthesis and Electrochemical Properties of Intermetallic PtPb Nanodendrites

We report on a facile and environment-friendly route to synthesize intermetallic PtPb nanodendrites with controllable compositions. This involves a hydrothermal-assisted coreduction of Pt and Pb inorganic precursors by formic acid in aqueous solutions without the use of any surfactant or polymer. Our systematic structural characterization and in situ electrochemical infrared spectroscopic studies of the formed PtPb nanodendrites reveal that the underlying morphogenesis, resulting from the intermetallic phase evolution from a Pt-based face-centered cubic to a PtPb hexagonal type, is responsible for the significant improvement of electrocatalytic activities toward the electrochemical oxidation of formic acid. A foreign-particles-induced growth mechanism is proposed to account for the underlying dendritic growth process. The facile approach described in this study is further demonstrated to be universal for growing a variety of intermetallic nanodendrites, thus opening a door to develop and study novel nanodendritic materials.