Influence of Hydrochloric Acid Concentrations on the Formation of AgCl-Doped Iron Oxide-Silica Coreshell Structures
Silver chloride (AgCl) nanoparticles with the average size of about 45 nm have successfully been doped onto the iron oxide-silica coreshell surfaces by a simple room temperature wet chemistry method under ambient atmosphere. The Stöber process has been used to make the coreshell structure, followed by adsorption of Ag+ species on silica surface prior to the addition of hydrochloric acid (HCl) and polyvinylpyrrolidone (PVP). The concentration of HCl acid that was used to induce the growth of AgCl particles was varied from 0.12 mM to 12x103 mM of concentrations. Results showed that at a very high concentration of HCl (12x103 mM), large AgCl agglomerates (0.3-0.6 microns) with irregular cubic-like morphology were obtained while at a very low, 12 mM HCl concentration, 30-50nm AgCl particles having a uniform cubic morphology were observed. Concentrations below 12 mM result in irregular and nearly spherical morphology of AgCl particles with a smaller size (28-60 nm). UV-Vis absorption of the composite materials showed absorption in the visible wavelength indicating that Ag nanoclusters might coexist together with AgCl particles.
Pietro Vincenzini, Yoon-Bong Hahn, Salvatore Iannotta, Andreas Lendlein, Vincenzo Palermo, Shashi Paul, Concita Sibilia, S. Ravi P. Silva and Gopalan Srinivasan
N. Mahmed et al., "Influence of Hydrochloric Acid Concentrations on the Formation of AgCl-Doped Iron Oxide-Silica Coreshell Structures", Advances in Science and Technology, Vol. 77, pp. 184-189, 2013