A simple hydrothermal method for the preparation of 3D petal-like Ni(OH)2/g-C3N4/RGO composite with good supercapacitor performance

Abstract High performance electrode materials have always been the key of supercapacitor research. Herein, we have prepared a kind of Ni(OH)2/g-C3N4/RGO nanosheet composite with petal-like structure, which was prepared by a simple hydrothermal method. The growth of Ni(OH)2 based on g-C3N4/RGO nanosheets owning to a more loose structure between the layers, which provided a sufficient electron transfer region for the Ni3+/Ni2+ in the redox process. In addition, the specific capacitance of Ni(OH)2/g-C3N4/RGO electrode was 543.8 F/g at 1 A/g, and also shown good cycling stability (72.7% retention over 2000 cycles). We assembled an asymmetric supercapacitor with Ni(OH)2/g-C3N4/RGO and activated carbon electrodes. The maximum energy and power density of the device were 33.38 Wh/kg and 849.8 W/kg respectively. The cyclic stability was 71.72% after 6000 cycles. Furthermore, the Ni(OH)2/g-C3N4/RGO nanosheet composite prepared provided a theoretical basis in the field of energy application research.