反应物的相间分配对吸附相技术制备纳米CuO过程的影响

以SiO2表面的富水吸附层为纳米反应器制备CuO纳米粒子. 不同水量下的吸附量测定、溶剂置换和反应后吸附对比实验结果表明, SiO2表面存在吸附水层, 并且该吸附水层是反应的主要场所. 根据吸附数据, 认为Cu2+在体系中具有三区域浓度分布特点, 体系中水浓度和氢氧化钠浓度的增加均会使得Cu2+向吸附层区域迁移. XRD分析结果表明, 反应温度的升高和NaOH浓度的增大有利于生成更小的CuO晶粒, 其中温度的升高使吸附层厚度减小, 限制了晶粒生长; NaOH浓度的增大则会增大层内溶质过饱和度, 导致晶核形成速率加快.

Influence of Interphase Distribution of Reactants on Preparation of Nano-CuO by Adsorption Phase Technique

CuO nanoparticles were synthesized in a nanoreactor formed by adsorption layer on silica surface. Adsorption capacity measuration experiment with different water concentrations, solvent substitution experiment and reaction-before-adsorption experiment showed that the water adsorption layer existed on the SiO2 surface and served as a place reaction mainly occurring. The three-region distribution model of Cu2+ in this system was proposed according to the adsorption data. The increase of water concentration and NaOH concentration in system will both made more Cu2+ migrate to the adsorption layer region. XRD analysis indicated that the rise of temperature and the increase of NaOH concentration were both in favor of the smaller CuO grain formation. The growth of CuO grain was restricted by the adsorption layer, which became thinner with temperature rising. And the nucleation rate accelerated as the supersaturation degree in adsorption layer increased with the NaOH concentration rising.