Controlled Synthesis Of Zno Hierarchy In Participation Of The Biological Molecules

Owning to ZnO materials have a unique structure, it showed excellent performance inelectrical, optical and magnetic properties. Now, it is a high-profile semiconductor material. Inrecent years, the use of biological molecules as additives in the preparation of materials hasbecome a hot topic. In this paper, DNA, sorbitol and citric acid were namely used asstructure-directing additives, we successfully prepared three kinds of unique structure andmorphology of ZnO crystals with liquid phase method under mild conditions. Also, theproduct surface morphology, internal structure, the photoluminescence performance andphotocatalytic properties, which were Detected by means of XRD, SEM, TEM, PL, UVtechnology. The influence of reaction conditions on the material structure, morphology andphotocatalytic properties were investigated in depth.The main research contents and results are listed as follows.（1） The synthesis of butterfly-shaped ZnO Controllable Preparation using DNA as astructure-directing additives.In this section, Zn（Ac）₂2H₂O solution and NaOH solution were used as a reaction rawmaterial. We prepared a monodisperse butterfly-shaped ZnO crystal particles by directprecipitation method. Experimental results show that the DNA played a role of structuredirecting agent. It is that promotes self-assembled of nanosheets and nanorods. Drawnthrough the experimental results, DNA added into experimental system can improve thephotocatalytic properties of the materials. In addition, through a comprehensive analysis ofthe experimental results, a possible synthesis mechanism was discussed.（2） Controllable Preparation of sea urchin-like ZnO with Sorbose addition.In this section, Zn（NO₃）₂·6H₂O and NaOH solution were used as a reaction raw material,sea urchin-like ZnO crystals were Prepared by direct precipitation method. Experimentalresults show that sorbitol added to the system not only play a significant role in generatingnanoneedles, but also to promote the self-assembly of nano-needle. Sorbose adding indirectlymake the system’s pH value maintained at pH=7. This condition is a key factor of synthesisof sea urchin-like ZnO. This part also explore the nucleation and growth mechanism of seaurchin-like ZnO. The impact of various reaction conditions to product’s morphology, crystalline phase and photoluminescence properties were discussed in depth.（3） Controllable Preparation of core-shell ZnO with citric acid involved.In this section, Zn（NO₃）₂·6H₂O and C₆H₁₂N₄were used as a reaction raw material.Prepared a homogeneous core-shell structure of ZnO crystals on ITO substrate withhomogeneous precipitation method. Experimental results show that citric acid added play adecisive role in the preparation of the core-shell structure of ZnO. Only by adding citric acidin the first step of the reaction will be produce the spherical structure ZnO crystals. PH andreaction time is also a key factor in forming the core-shell structure of ZnO in thesecond-stage reaction. At low pH values, the cavity of the core-shell structure will be notformed. At high pH values, it will form a hollow structure ZnO. The reaction time is too short,the core-shell structure is not obvious. The reaction time is too long, it will form a hollowstructure. Meanwhile, according to the influence of pH and the reaction time on themorphology core-shell ZnO, the growth mechanism were discussed in depth.