Abstract: 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.

Key words: Adsorption layer, Nanoreactor, Adsorption phase reaction technique, CuO nanoparticles