Recovery and immobilization of metal sulfide nanoparticles from reverse micellar system onto thiol-modified polystyrene particles

Metal sulfide semiconductor nanoparticles of CdS and ZnS-coated CdS, prepared in a reverse micellar system, were immobilized using thiol-modified polystyrene particles. Successful immobilization of the nanoparticles was achieved onto the surface of the polystyrene via thiol bonding and effected only by the addition of the polystyrene particles into the micellar solution under conditions of mild stirring. The introduction of a poly(ethylene glycol) chain between the thiol group and the polystyrene was found to enhance the percentage immobilization substantially. The resulting CdS- and ZnS-coated CdS-immobilized polystyrene composites could then be used effectively as photocatalysts for the generation of H-2 from 2-propanol aqueous solution, such that the wavelength region of photoabsorption is controlled easily and precisely by controlling the water content of the reverse micellar system used for nanoparticle preparation.