One-dimensional heterostructures of beta-nickel hydroxide nanoplates/electrospun carbon nanofibers: Controlled fabrication and high capacitive property

Ultra-long one-dimensional (1D) electrospun carbon nanofibers (CNFs) were obtained by carbonization treatment of polyacrylonitrile fibers at 1000 °C in nitrogen atmosphere. Using CNFs as templates, beta-nickel hydroxide (Ni(OH)2) nanoplates were prepared on CNFs by hydrothermal reactions. The contents of Ni(OH)2 in the 1D Ni(OH)2/CNFs heterostructures could be controlled by adjusting the concentrations of Ni(Ac)2 precursors. The 1D heterostructures as electrode materials of supercapacitors exhibited high specific capacitance compared with CNFs, pure Ni(OH)2 nanoplates, and physical mixtures of CNFs and Ni(OH)2 nanoplates. The excellent properties of the heterostructures could be ascribed to the rapid electron transport along the longitude direction of CNFs, the high specific pseudo-capacitance of Ni(OH)2 nanoplates, and the good electrical contacts between CNFs and Ni(OH)2 nanoplates. And, the specific capacitance retention of the heterostructures was over 90% after 500 cycles of charge and discharge at a high current density of 12.5 A/g, suggesting their good cycling stability. It was expected that the 1D Ni(OH)2/CNFs heterostructures as electrode materials with excellent capacitive properties would greatly promote their practical applications to the energy storage for supercapacitors.