Probing the Interaction of Heavy and Transition Metal Ions with Silver Nanoparticles Decorated on Graphene Quantum Dots by Spectroscopic and Microscopic Methods.

We report a comprehensive study of the interaction of transition and heavy metal ions with graphene quantum dots-capped silver nanoparticles (AgGQDs) using different spectroscopic and microscopic techniques. High-resolution transmission electron microscopy studies show that the interaction of metal ions with AgGQDs leads to the formation of metal oxides, the formation of zerovalent metals, and the aggregation of Ag nanoparticles (AgNPs). The metal ions may interact with AgGQDs through selective coordination with -OH and -COOH functionalities, adsorption on the graphene moiety, and directly to AgNPs. For instance, the interaction of Cd