One-pot synthesis of ZnO/reduced graphene oxide nanocomposite for supercapacitor applications

ZnO/reduced graphene oxide (RGO) nanocomposite films were prepared by the sol–gel deposition method using a combination of zinc acetate and graphite. The solution derived composite films were extensively characterized using high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–visible spectroscopy, photoluminescence emission measurements, and four probe measurements. It was found that a highly transparent film with low resistivity could be obtained with the addition of a small amount of RGO into the deposition precursor. The results also showed that the sintering temperature reduces the resistivity and transparency of the films. XRD measurements revealed that films sintered >500 °C exhibit additional peaks, and suggest nucleation of different phases of the films. As a demonstration, the ZnO/RGO composite was integrated into a supercapacitor, and the resulting energy storage performance was tested.