Design of nanoarchitecture for synergistic interactions to realize nanoflower-like Ni3S4 supported on graphene sheets as high-performance supercapacitor electrodes

The objective of this work was to prepare and evaluate Ni₃S₄/graphene nanostructures for making high-performance supercapacitor electrodes. A one-pot solvothermal method was developed to prepare the hierarchical nanostructures consisting of Ni₃S₄ nanoflowers on graphene nanosheets. Due to the hierarchical structure of Ni₃S₄ nanoflowers on graphene nanosheets, the resulting electrodes exhibited high supercapacitive performance. Herein, the Ni₃S₄/graphene electrode demonstrated the specific capacitance of 978.4 F g^–1 at the current density of 0.5 A g^–1, the rate capability and long-term cycling stability were also excellent. Moreover, the capacitance contribution of NG-60 can reach 87.9% of the total capacity at 10 mV s⁻¹. The high pseudo-capacitive performance can be attributed to the superior electronic conductivity of graphene nanosheets and the well interconnected tiny pores/channels in the Ni₃S₄ nanoflower arrays. The prepared Ni₃S₄/graphene hierarchical nanostructures may be promising as innovative electrode materials for making high-performance supercapacitors.