Preparation And Characteriztion Of Bismuth Nanoparticles And Bismuth Oxide

Nanomaterials have been the focus of extensive studies worldwide due to their unique physical and chemical properties distinct from those of bulk. Bismuth provides a very attractive model system for studying physical phenomena owing to the lightest effective masses and the longest mean free path in all materials, with excellent thermic properties, electric properties and magnetism. In this dissertation, the synthesis of bismuth nanospheres, nanotubes, single-crystalline nanoplates and bismuth oxide nanosheets and micro-needles has been explored. A newly rational synthetic route has been presented for the synthesis of metallic bismuth nanotubes and nanospheres in an aqueous solution with low temperature and normal pressure. A method of liquid-phrase precipitation by one step has been demonstrated for the synthesis of bismuth oxide nanomaterials (micromaterials).The wet chemical synthesis process of bismuth nanoparticles has been studied systematically to examine the processing parameters that control morphology and purity. An aqueous chemical reduction method has been proposed to prepare nanocrystals of bismuth using hydrazine hydrate as reductive agent in alkaline medium. The effect of reaction temperature, solvent , concentration of reductive and surfactants on the formation of bismuth have been described in detail using XRD, TEM, EDX, ICP and DTA-TG. It was found that bismuth nanoparicles with higher thermal stability and anti-oxidated ability derived by aqueous reduction process at 80℃for 60 min. In addition, it is observed that bismuth nanoparticles melted upon beam irradiation and gathered together.Several synthetic techniques have been applied to synthesize bismuth nanoparticles, including hydrothermal method, sonachemical method, and reduction with reverse micelles. In this article, we showed a relatively simple approach for controlling the synthesis of bismuth nanocrystals. In contrast to organic and other methods, this approach is environment friendly and limitation of energy consume.Another part of research work is the production of bismuth oxide nanosheets and microneedles. We prepared pure bismuth oxide nanosheets by liquid-phrase precipitation through one step. Besides, the bismuth oxide microneedles with cavum were synthesized in the present of surfactant at relative low temperature under normal pressure. We found that the morphology of bismuth oxide microneedles was influenced by reactive temperature, additive sequence of stock materials, species and quantity of surfactants.In short, we tried to use mild method to prepare some nanomaterials which was synthesized complicatedly by conventional methods.