纳米ZnO的沉淀法制备、表征及影响因素分析

用Zn(NO₃)₂·6H₂O对作原料、Na₂CO₃作沉淀剂,制得了纳米ZnO粉体.用TG-DSC、XRD和TEM分别对前驱体和纳米ZnO粉体进行了表征.结果表明:所得前驱体在253℃左右分解为六方纤锌矿型纳米ZnO,颗粒大小约为15～20nm,粒径分布窄,基本无团聚,粉体的比表面积为64.12m²·g^-1实验发现,当反应物浓度从2.0mol·L^-1减小至1.0、0.5mol·L^-1时,纳米ZnO粉体的粒径基本无变化,但颗粒间的团聚状态减轻;在用无水乙醇洗涤沉淀前,先用蒸馏水或稀氨水清洗对得到的纳米ZnO粉体的团聚状态没有明显的区别.

Preparation, Characterization and Influential Parameters of ZnO Nanoparticles Synthesized by Precipitation Method

ZnO nanoparticles were synthesized by a precipitation method with Zn(NO₃)₂·6H₂O as the starting material and Na₂CO₃ as the precipitant. When the concentration of the reactants reduced from 2.0 to 0.5mol·L^-1, the particle size hardly changed but the agglomeration was weaker. TG-DSC curves of the precursor show that the precursor decomposes at about 253℃. XRD pattern of the powder indicates that the hexagonal wurtzite ZnO nanocrystals can be obtained when the precursor calcinated at 300℃ for 2h. TEM micrographs show that the ZnO nanoparticles are well dispersed and the average particle size is 15～20nm. The specific surface area of the obtained powder is 64.12m²·g^-1. There is no obvious difference whether to wash the precipitate by distilled water or ammonia before to wash by ethanol.