Solution-processed anchoring zinc oxide quantum dots on covalently modified graphene oxide

The combination of semiconductor quantum dots (QDs) and graphene or graphene oxide is attracting much attention due to its unique properties and potential applications for optoelectronics or photocatalysts. Here a solution process is reported to firmly anchor zinc oxide QDs on the surface of graphene oxide by a covalent method. The graphene oxide is obtained with a modified Hummers method and slightly reduced and modified with hydrosulfide groups. Zinc oxide QDs are ultrasonically mixed with the modified graphene oxide and then anchored on the surface due to the strong interaction of Zn-S bond. The mixture is analyzed with transmission electron microscopy, energy dispersive spectroscopy, and Raman spectroscopy in details. Further photoluminescence spectroscopy and photoelectrical characterizations exhibit that charge transfer happens between zinc oxide QDs and graphene oxide, indicating it should have potential applications for optoelectronics and photocatalysts.