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

摘要

Ultra-long one-dimensional (1D) electrospun carbon nanofibers (CNFs) were obtained by carbonization treatment of polyacrylonitrile fibers at 1000 ℃ 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.