Nanomaterials Of Copper And Zinc Family: Synthesis, Characterization And Property Investigation

Nanomaterials of copper and zinc family have exhibited promising applications in the fields of catalysis, optoelectronic devices, sensors, cells and biology. Exploring novel synthesis routes and understanding their formation mechanism should be a key precondition to reveal the relations between the structures and properties, and subsequently to develop low-cost materials but with high performance. In this dissertation, a systematic research is presented on four kinds of materials in copper and zinc family: intermetallics and alloys, oxides, II-VI semiconductors, and complexes, mainly for improving the reported synthesis approaches, developing new strategies, investigating the formation mechanism, and then understanding the key connections between the performance and size, shape, and composition of the nanocrystals.Making use of the reaction between Au nanoparticles and freshly reduced Cu atoms which have high reactivity, Au-Cu intermetallic and alloyed nanocrystals have been prepared. The reaction mechanism was investigated in details. This synthetic methodology provided a creative clue that"moving"a solid-state reaction into solution may allow homogeneous diffusion and need less time and thermal energy but produce monodisperse nanocrystals. And it was also powerful for the preparation of other alloy nanocrystals. Their catalytic activity for CO oxidation showed that intermetallic and alloyed noble–nonnoble nanocrystals may be the ideal candidates of new low-cost catalysts with high performance.Based on the reductive activity of polyol, a solvothermal reaction route was developed to fabricate Cu₂O nanostructures, which then served as templates for the chemical conversion synthesis of porous Cu₉S₅, CuS, and CuO nanostructures.Due to the exposure of high-energy {001} facets, the fabrication of triangle-shaped CdS nanocrystals with wurtzite structure has being a great challenge. Considering that a solvothermal protocol has great advantages in controlling the crystal growth in a dynamic region, it was successfully employed to get triangular CdS nanocrystals after preparatory experiments and rational analysis. The shape purity, stability, and size-distribution of the as-prepared nanocrystals were fair better than the reported research. The relationship between photoluminescence and the size and shape was studied. In addition, a surface oxidation method (top-down) was developed to obtain different emissions of the semiconductors, providing a new clue for tuning the luminescence of semiconductors.Taking use of the different solubility in two solvents, an emulsion-based reprecipitation strategy was designed for the growth of Alq₃ nanorods, a possible formation mechanism of which was provided and was proved by experiments. A single rod possessed different emissions from those of aggregated rods under intensive excitation, which was promising building block for novel optical devices. The designed reprecipitation method overcame the defect of traditional reprecipitation routes that the good solvent and the poor one must dissolve each other perfectly, making the clue of reprecipitation suitable for the fabrication of nanocrystals of more organic materials. Additionally, a direct precipitation reaction was designed to prepare Cdq₂ nanostructures. The connection between luminescence intensity and the size was investigated.