Cadmium ion adsorption controls the growth of CdS nanoparticles on layeredmontmorillonite and calumit surfaces

Adsorption isotherms have been determined for the intercalation of cadmium ions (Cd2+) into layered hydrophobized montmorillonite (HDP-M) and calumit (DBS-C) sheets dispersed in ethanol (1)-cyclohexane (2) mixtures. The amoun t of Cd2+ adsorbed depended strongly on the composition of the binary liqui d; at an ethanol mole fraction of 0.05 (x(1) = 0.05), 95% of the added Cd2 is located in the ethanolic nanoreactor at the HDP-M (or DBS-C) surface. C dS nanoparticles have been generated in situ in ethanolic nanoreactors at t he HDP-M and DBS-C surfaces. Absorption spectrophotometric measurements pro vided information on the number of CdS nanoparticles formed and on their ab sorption edges, bandgaps, and mean diameters. Good correlations have been o btained between the adsorption isotherms and the size (and the amount) of t he CdS formed. X-ray diffractometry established that CdS nanoparticles stre tched the HDP-M and DBS-C lamellas unevenly upon intercalation. (C) 1999 Ac ademic Press.