Shape-controlled Synthesis Of Ultrafine Pt Nanodendrite And Thestudy Of Its Multifunction

Transition metals(Pt, Pd, Au, Ag, etc.) and their alloys have hitherto attracted a great deal of attention due to their exceptional catalytic, electrical and corrosion resistive properties. As a matter of fact, the development of petrochemical industry, clean energy harvesting, analytical sensor and environmental protection have long been benefited from the research progress on the nanostructured noble materials synthesis and characterization. It has been widely accepted that the morphology tailoring of noble materials with nanoscale precision contributes significantly to their chemical and physical properties, and thus may give a rise to the next generation functional materials. Nanodendritic materials with hierarchy morphology are widely utilized in the fields of catalysis, optics and sensing techniques. The preparation of shape-tunable nanodendritic particles however, is still one of the outstanding synthetic challenges.Herein, Shape-controllable ultrafine platinum(Pt) nanodendrites have been synthesized by a facile, one-step pulse electrodeposition method. Based on the crystalline information of the as-prepared Pt particles as well as electrochemical principles, we propose the possible growth mechanism of the various deposit morphology in our experiment. Meanwhile, the localized electric field enhancement and localized surface plasmon resonance(LSPR) of Pt nanodendrite have been systematically investigated via the combination of experiments and theoretic study.The major research conclusions are as follow:1. The particle morphology went through a transition from hemisphere, nanoflower to nanodendrite by altering anodic potential of pulse electrodeposition. The ultrafine tertiary branches on the dendrite exhibited an extremely small diameter of 10-20 nm. It was found that the preferential growth direction of the tips differs from the dendrite hierarchy, which is <111>, <110> and <311> of the trunk, secondary and tertiary branch, respectively.2. Catalytic performance of the platinum towards methanol catalytic combustion turned out to be in the order of dendritic> flower-like > hemispherical Pt particles. Typically, the turnover frequency(TOF) of Pt dendrites reached 0.33 mmol· min-1· mg-1 at 150 oC, which is four times that of the spherical one.