Silica Encapsulated CdS Tabular Nanocomposites via a Template Directed Agglomeration Mechanism

Abstract

Silica coated CdS tabular nanocomposites were synthesized through precipitation of CdS nanoparticles in octylamine/water bilayer system followed by in situ hydrolysis of tetraethoxylsilicate (TEOS) precursor. Face diameter of the nanoplatelets was in the range of 50-250 nm with a variable thickness (3 to 25 nm) dictated by octylamine content or R ratio ([water]/[octylamine]). A uniform SiO2 outer shell of about 15 nm was observed regardless of the size of the high aspect ratio CdS nanoplatelets, which appeared to be agglomerated primarily owing to the confined bilayer template. Morphology and microstructure of the CdS/SiO2 tabular nanocomposites were characterized using atomic force microscope (AFM) and high resolution transmission electron microscope (HRTEM). A noticeable enhancement in absorbance for the UV-vis spectra was observed due to the SiO2 coating layer. Growth mechanism of nanocomposite platelets and potential applications associated with this anisotropic nanocomposite are discussed.

Synthesis of Inorganic Nanocomposites by Selective Introduction of Metal Complexes into a Self‐Assembled Block Copolymer Template

“…Templating processes that use organic materials as molds are powerful methods for controlling inorganic nanocomposites' structures [28][29][30][31]. In particular, block copolymers are fascinating templates for the control of nanostructures of inorganic nanocomposites, because the copolymers selfassemble into specific morphologies of spheres, hexagonally packed cylinders, and lamellae with periodic order typically in the range of several to several tens of nanometers [32][33][34][35][36][37][38][39][40][41].…”