Synthesis of magnetic ion-imprinted fluorescent CdTe quantum dots by chemical etching and their visualization application for selective removal of Cd(II) from water

A novel magnetic Cd(II)-imprinted fluorescent CdTe quantum dot (Fe3O4@CdTe-IIP) was synthesized through chemical etching strategy without the use of functional monomer and cross-linkers, and was used as an adsorbent for the removal of Cd(II) from water. Fe3O4@CdTe-IIP not only shows much higher adsorption capacity and selectivity for Cd(II) than the non-imprinted counterpart (Fe3O4@CdTe), but also exhibits good photoluminescence and magnetism. The adsorption capacities of Fe3O4@CdTe-IIP and Fe3O4@CdTe for Cd(II) ions are 17.57 and 8.03 mg/g, respectively. The studies of adsorption kinetics show that the adsorption rate of Fe3O4@CdTe-IIP is fast, and the adsorption process fits well with a pseudo-second-order model. Moreover, the progress of the adsorption of Cd(II) ions on Fe3O4@CdTe-IIP can be monitored according to color change of Fe3O4@CdTe-IIP because of its fluorescent recovery.