Incorporation of CdS nanoparticles formed in reverse micelles into silica matrices via a sol-gel process:: preparation of nano-CdS-containing silica colloids and silica glass

The incorporation of CdS nanoparticles, as prepared in reverse micellar systems, into silica matrices, via a sol-gel process, was investigated. The silica colloids containing CdS nanoparticles, CdS-COL, were prepared via the surface modification of CdS nanoparticles using 3-mercaptopropyltrimethoxysilane in reverse micelles. The recovery and dispersion of the nanoparticles was performed in an appropriate organic solvent, followed by a sol-gel process, using TMOS (tetramethyl orthosilicate) or TEOS (tetraethyl orthosilicate) in MeOH or EtOH solution. The size and morphology of the resulting CdS-COL was able to be controlled by changes in the silica source and the organic solvents. A CdS-COL stable against photoirradiation and heat treatment was able to be prepared which could be utilized as a photocatalyst for the generation of H-2 from propan-2-ol aqueous solution. The silica bulk glass containing the CdS nanoparticles, CdS-GLA, was also prepared, such that the cut off wavelength of the glass could be precisely controlled by regulating the water content (W-o) for the reverse micellar system, during CdS preparation.