▎ 摘　　要

Tremendous research efforts have been aimed at ever-increasing worldwide energy demand. For this purpose, the hybrid supercapacitor power cell were prepared composing 3D porous graphene decorated with Co3O4-CeO2 nano-particles herein by using flower stem as biotemplate. The resulting samples were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectra, X-ray diffraction spectroscopy (XRD), nitrogen adsorption and desorption, X-ray photoelectron spectrogram (XPS), and electrochemical test. The 3D graphene acted as an excellent carrier together with Co3O4-CeO2 nano-particles, boosting the specific capacitance of composite (221 F/g), which exceeded the theoretical value limit. This facile biotemplate method of research provided an eco-friendly and cut-price route to obtain high-quality graphene and Co3O4-CeO2 nano-composites owing to the unique porous structure derived from original template (flower stem). The finding presented a simple strategy for fabrication of novel energy storage devices.