The Co-Assembly of Polyoxometalates and Quantum Dots for Hybrid Core-Shell Nanoparticles

Graphical A phase transfer approach to controllably assemble core-shell nanoparticles through two different sized CdSe QDs and tri-lacunary Keggin-type POMs functionalized with thiol groups. A co-assembly protocol of quantum dots (QDs)-polyoxometalates (POMs) hybrids is developed using Keggin-type POMs as surface capping ligands. Phase transfer strategy is used to prepare POM-QDs nanocomposites. These newly developed hybrid materials have been explored for their optical properties and aggregation behavior in solutions. UV/Vis and FT-IR are used to reveal the optical properties of POM-QDs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) are applied to characterize the co-assembled core-shell structures of POM-QDs complexes under different reaction conditions. A general trend to be noted is that the average photoluminescence (PL) lifetime of QDs decreases after phase transfer. The lifetime attenuation is caused by the surface property change of newly obtained POM-QDs complexes, which is resulted from the changed band edge recombination and shallow trap assisted recombination.