Synthesis and characterization of silver nanoparticle/kaolinite composites

Ag nanoparticles were synthetized in the interlamellar space of a layered kaolinite clay mineral. Disaggregation of the lamellae of non-swelling kaolinite was achieved by intercalation of dimethyl sulfoxide. The kaolinite was suspended in aqueous AgNO3 solution and, after adsorption of Ag+, the ions were reduced with NaBH4. The interlamellar space limits particle growth (d(ave) = 3.8-4.2 nm); however, larger silver particles may be formed on the exterior surface of kaolinite with d(ave) = 5.6-10.5 nm diameter. The diameter of the particles prepared in this way is depending on the initial AgNO3 concentration. The silver nanoparticles prepared were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Small angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). (C) 2003 Elsevier Science B.V. All rights reserved.