A Carl Zeiss Ultra 1540 dual beam scanning electron microscope (SEM) was used to determine the morphology of the ZnO QDs- graphene composite. High resolution transmission electron micro-scopy (HR-TEM) studies were carried out in a HR-TEM microscope (JEOL2011) at an operating voltage of 200kV. X-ray diffraction (XRD,PANalytical) pattern of the ZnO QDs-graphene composite was measured at room temperature using Cu Kα radiation.