Diverse comparative studies for preferential binding of graphene oxide and transition metal oxide nanoparticles

Graphene oxide being a low-cost material with multiple functionalities and well-known spectroscopic properties is studied for its preferential binding through its functional groups with Fe 3 O 4 , CoO, NiO, CuO and ZnO NPs using various techniques, where CoO nanoparticles have shown the highest binding affinity among these metal oxide nanoparticles. Transition metal oxide nanoparticles along with carbon-based materials have been used for various applications, however the interactive behavior of these two classes of materials have never been understood in detail to reveal the functionalities that are important for the binding. This is so far only known about noble metal nanoparticle – graphene oxide hybrids, which are not only expensive but have limited functionalities. This understanding will not only improve the already reported applications of transition metal oxide composites but also potentially realize new applications, e.g., sensors for the detection of various moieties. • The binding mechanism of graphene oxide and transition metal oxide nanoparticles was investigated. • Fe 3 O 4 , CoO, and NiO nanoparticles interact via C C bonds, whereas CuO interacts via hydroxyl gropus of graphene oxide. • The strength of interaction with graphene oxide is in the order of CoO > Fe 3 O 4 > ZnO > NiO > CuO. • Metal oxides do not interact with carbonyl functional groups of graphene oxide. • These nanoparticles show both static and dynamic queching except CoO, which prefers single type of quenching.