Synthesis Of Au Aerogel And Au/Pd Core/Shell Nanowire And Their Catalytic Properties

Noble metal nanomaterials have potential applications in the fields of energy,analysis and organic synthesis and so on.Developing size-and morphology-controllable synthetic technique is a prerequisite for linking the properties with the structure/size of noble metal nanomaterials and promoting their commercialization application.Based on this,this thesis developed novel strategies for producing Au aerogel and Au/Pd core/shell nano wire and explored their catalytic or optical performances.The main contents are as follows:?1?Achieve well-defined Au aerogel by one-step,surfactant-free method at room temperature and investigate its catalytic performance and surface-enhanced Raman scattering?SERS?effect.The results showed that Au aerogel could effectively catalyze the reduction of p-nitrophenol and exhibit excellent long-term catalytic stability:its catalytic performance almost remained as the initial after 18-time repeated utilization.In addition,Au aerogel was also a good SERS substrate:the enhancement factor?EF?was up to?10⁴ towards rhodamine 6G?R6G?.?2?Achieve jagged Au/Pd core/shell structure nano wires with the assistance of dual-surfactants.Scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray diffraction?XRD?and energy dispersive X-ray?EDX?elemental mapping analysis were employed to characterize its morphology and element distribution.The formation mechanism was proposed involving galvanic replacement,directional coalescence and site-selective growth.The results showed that the morphology and thickness of Pd shell were tunable dependent on the ratio of Au and Pd precursors and a series of Au/Pd core/shell nanowires with adjustable composition and shape were created.?3?Disclose the correlation between the electrocatalytic performance and the composition and structure of Au/Pd core/shell nanowires by electrooxidizing ethanol and formic acid.All resulting Au/Pd core/shell nanowires had excellent catalytic activity towards ethanol and formic acid.However,in the case of different catalytic reactions,the Au/Pd atom ratio of nanowires dictated their long-term catalytic durability.Au₅₀Pd₅₀ and Au₃₆Pd₆₄ nanowires had the best catalytic activity and durability for ethanol and formic acid electrooxidation,respectively,?8 and?2 times in the specific activity higher than commercial Pd/C.