Platinum-based Heterogeneous Nanomaterials And Their Electrocatalytic Performance

The noble metal-based nanomaterials has an important application prospect in the field of catalysis, especially platinum-based noble metals nano catalyst(methanol fuel cell and lithium air batteries, etc.) has an important position in developing of fuel cells. The structure effect physicochemical properties, the structure determines catalytic performance. So structure regulation with heterostructure(dendritic, stellated, polyhedral, hollow, composite, etc.) of platinum-based noble metals nano catalyst to enhance its catalytic activity is particularly important. But under the condition of a global shortage of noble metal resources, the preparation methods to obtain high selection, high catalytic activity, high stability of catalysts make the further development of platinum-based noble metal catalyst become possibility. At the nanoscale, the electronic coupling effect and the effect of the lattice strain between different metal components made the nano catalyst show its special performance and application characteristics, which effectively expanded its application field. Based on the effective control measures on structure to achieve the high-enhanced performance of catalyst, the noble metals nano catalyst exhibited potential value and attractive prospect in photocatalysis, electrocatalysis, chemical catalytic reaction and the manufacturing of optical, electrical devices, etc.This thesis mainly focuses on the structure regulation of platinum-based metals heterostructure nano catalyst and the application of the catalytic performance in electrocatalysis. Besides, the preparation of the semiconductor-metal nanocomposite with heterogeneous structure is mentioned as the expansion. Using seed-mediated growth, structure evolution, electric displacement and metal deposition method and so on, a series of novel and peculiar nanoparticles with heterostructure are obtained, and the characterization and electrochemical catalytic performance test are done, this paper expounds the synthetic mechanism and growth process and illustrates the potential electronic coupling effect and synergy effect between different metals in alloy nanoparticles, it reveals the inevitable link between the morphology structure of catalyst, physicochemical properties and catalytic properties.Using seed-mediated growth, the dendritic, stellated, polyhedral structure of Cu-Pt noble metal catalysts were synthesized with regulating copper and platinum precursor. The research Clarified the mechanism of bimetal alloying growth process, it also revealed the structure of catalyst particles, electronic coupling effect which influence on methanol catalytic activity; And we had further explored the Cu-Pt alloy system with polyhedral structure. We observed a novel phenomenon that the synthesized Cu-Pt nanoparticles with a core-shell construction could be transformed into alloy Cu3 Pt nanoframes in a non-polar organic medium. The evolution of the structure changing in morphology was tracked over time. Cu-Pt core-shell structure nanoparticles exhibit good catalytic activity to methanol oxidation reaction while alloy Cu3 Pt nanoframes show high-performance for oxygen reduction reaction;On the basis of the electronic coupling effect, the semiconductor-metal(Hg S- Au) heterostructure nanoparticles were synthesized as extension research, by regulating the proportions of two different solvents(oleyamine and oleic acid) and the reaction temperature, Hg S semiconductor nanoparticles with different morphology were formed in the phase transfer-based method. Through the metal deposition method, Au ion deposited onto the surface of the semiconductor Hg S. Hg S – Au noble metal nanoparticles with different deposition sites were obtained by controlling the reaction time.