吸附相反应技术制备纳米ZnO/SiO_2

Preparation of ZnO/SiO_2 Nanoparticle by Adsorption Phase Reaction Technique

采用吸附相反应技术制备ZnO/SiO_2纳米复合材料,考察了反应途径、体系中水含量和NaOH浓度对ZnO/SiO_2纳米复合材料的影响,并采用透射电子显微镜(TEM)、X-射线衍射(XRD)、酸碱滴定和络合滴定等手段对ZnO/SiO_2纳米复合材料进行了表征。结果表明,利用吸附相反应技术能有效调控ZnO粒子粒径,吸附质种类与浓度以及吸附层厚度与性质均会影响粒子的粒径。随着吸附层厚度的增大,粒径逐渐增大;随着物理吸附层的形成以及吸附质浓度增高,粒径逐渐变小。与Ag纳米粒子制备过程对比,发现制备Ag和ZnO粒子的反应机理不同导致两种粒子的形成和生长过程有较大差异。

ZnO/SiO2 nanocomposite materials were prepared by the adsorption phase reaction technique. The effects of synthesis routes, water content of reaction system and NaOH concentration on ZnO/SiO2 nanocomposite materials were investigated and the transmission electron microscope （TEM）, X-ray diffraction （XRD）, complexometric titration and acid-base titration were used to characterize ZnO/SiO2 nanocomposite materials. It was found that the particle size was effectively controlled by the adsorption phase reaction technique. And the particle size would be influenced not only by kind and concentration of adsorbent, but also by morphology and performance of adsorption layer. When the thickness of adsorption layer increased, the particle size would increase. The formation of the physical adsorption layer and the increase of the adsorbent concentration made the particle size decrease. Compared with preparation of Ag particle, the formation and the growth of Ag particle and ZnO particle were different resulting from the difference of reaction mechanism of preparation of Ag particle and ZnO particle.