Growth of nearly monodisperse palladium nanoparticles on disaggregated kaolinite lamellae

摘要

Palladium nanoparticles were prepared by in situ growth between kaolinite layers. Expansion of the interlayer space kaolinite was effected by intercalation of dimethyl sulfoxide (DMSO) at 65℃. The basal spacing increased from 0.72 to 1.12 nm during this process. After washing with methanol (partial displacement of DMSO ), nonionic poly(vinylpyrrolidone)/kaolinite, cationic poly(diallyldimethylammo-nium)/kaolinite and octylammoni-um/kaolinite complexes were generated by adsorbing the polymer or the surfactant from solution. Kaolinite samples containing palladium nanoparticles were prepared by hydrazine and NaBH_4 reduction of palladium ions adsorbed from a solution of H_2PdCl_4 (pH 4). The size of the palladium particles formed was determined by transmission electron microscopy measurements which showed that nearly spherical, nearly monodisperse particles of size of about 1 nm were generated.