Abstract: A new kind of preparation method of CdS/TiO₂coupled semiconductor nanoparticle in aqueous solution is described, in which CdSis in-situ formed on the surface of TiO_2.Furthermore, coupling of the two semiconductor particles via the bifunctional thiols offers an opportunity to sensitize TiO₂with a large bandgap and energetically low-lying conduction band by CdS with a small bandgap and an energetically high lying conduction band. IR spectra were used to follow the formation process of this coupled nanoparticles. UV-V is spectra illustrated well the stability effect of TiO₂on the formation of CdS nanoparticles. The quenching of CdSemission indicated that there were an effective charge separation between dissimilar semiconductor particles.

Key words: Coupled semiconductor nanoparticles, Modification, Stabilized effect, Charge separation