C3N4 improved nickel-cobalt layered double hydroxide (NiCoLDH) supercapacitive property

A flower-like composite of NiCoLDH/C3N4 is prepared using a simple one-step hydrothermal method. The morphologies and structure information of samples are observed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties are measured by an electrochemical workstation and Land. The effects of the C3N4 mass loading on the capacitance of NiCoLDH/C3N4 composite are studied. The results show that the NiCoLDH/C3N4 composite exhibits a flower-like morphology and presents an impressive specific capacitance of 2677 F g−1 at 1 A g−1 for the optimized sample with C3N4 mass loading of 5 mg, higher than that of the pristine NiCoLDH (1676 F g−1). In addition, the assembled NiCoLDH/C3N4//YP50 supercapacitor device could achieve a maximum energy density of 33 Wh kg−1 and show a good capacitance retention of 97 % after 9000 cycles.