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 sys tems, into silica matrices, via a sol-gel process, was investigated. The si lica colloids containing CdS nanoparticles, CdS-COL, were prepared via the surface modification of CdS nanoparticles using 3-mercaptopropyltrimethoxys ilane in reverse micelles. The recovery and dispersion of the nanoparticles was performed in an appropriate organic solvent, followed by a sol-gel pro cess, using TMOS (tetramethyl orthosilicate) or TEOS (tetraethyl orthosilic ate) 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 orga nic 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 regulatin g the water content (W-o) for the reverse micellar system, during CdS prepa ration.