Selective synthesis and characterization of CdTe@Mn(OH) 2 (core–shell) composite nanoparticles

Abstract

Multi-functional CdTe@Mn(OH) 2 core–shell nanoparticles were synthesized in aqueous solution by a seed-mediated growth approach. Initially, CdTe nanocrystals were synthesized with bi-functional molecule mercaptoacetic acid as a stabilizer. The Mn 2+ in the form of MnCl 2 was added to CdTe nanocrystals in aqueous solution and slowly hydrolyzed to deposit a layer of hydroxide (Mn(OH) 2) onto the luminescent CdTe nanocrystals as a core in the presence of stabilizer at pH ≈ 11.2. The effect of refluxing time and the concentration of Mn 2+ on the optical properties of these samples were evaluated using UV–vis absorption and photoluminescence analysis. The emission peak of the (CdTe@Mn(OH) 2) composite nanoparticles shifted to 640 nm from 605 nm (CdTe seed). The sizes of CdTe and CdTe@Mn(OH) 2 composite nanoparticles averaged about 3.22 nm and 7.94 nm respectively.