采用聚氨酯模板法制备花形纳米氧化锌

以乙酸锌(Zn(CH3COO)2)为锌源,尿素(CO(NH2)2)为碱源,非离子型聚氨酯(PU)为模板,采用水热法制备碱式碳酸锌(Zn5(CO3)2(OH)6)前驱体.在400 ℃进一步煅烧前驱体2 h,即获得氧化锌粉末.用粉末X射线衍射和扫描电镜研究产物的形貌和结构.结果表明:以PU为模板制备的氧化锌可以获得由纳米片状结构组成的花状形貌,PU的加入可以有效减小氧化锌的晶粒尺寸.进一步研究反应物的组成、反应温度及反应时间对产物结构的影响,发现当体系中碱源(OH-)和锌源(Zn2+)的摩尔比为4,水热反应时间为18 h,反应温度为150 ℃时,前驱体可以获得最完整的花状形貌,并且煅烧后氧化锌的花形形貌不变.

Preparation of flower-like ZnO nanocrystals using polyurethane as template

The precursors, basic zinc carbonate (Zn_5(CO_3)_2(OH)_6), were synthesized under hydrothermal conditions with zinc acetate (Zn(CH_3COO)_2) as zinc source, urea (CO(NH_2)_2) as alkaline source, and nonionic polyurethane (PU) as template. Zinc oxide (ZnO) powders were obtained when the synthesized precursors were calcined at 400 ℃ for 2 h. The morphology and structure of ZnO powders were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that the morphology of ZnO synthesized by using Polyurethane as a template is flower-like with lamellar structure, PU could cause efficiently the nanoparticle size of ZnO to reduce. The influence of the compose of reactant, the reaction temperature and the reaction time on the product morphology was also investigated. It is found that the morphology of the precursors is the flower-like. When the molar ratio of alkaline source (OH~-) to zinc source (Zn~(2+)) is 4, the hydrothermal reaction time is 18 h and the reaction temperature is 150 ℃. Moreover, the morphology of zinc oxide powders inherits that of the precursors.