Controllable synthesis of Ni-Co nanosheets covered hollow box via altering the concentration of nitrate for high performance supercapacitor

Abstract

It has been well accepted that the performance of supercapacitor material highly depends on its morphology, thus the control on morphology is significant for acquiring advanced materials. Herein, a facile method for controllable synthesis of nickel-cobalt layered double hydroxide (Ni-Co LDH) with a unique hollow structure is presented. In which zeolitic imidazolate framework-67 (ZIF-67) nanocrystals are used as templates and etched in a nitrate solution. The morphology of Ni-Co LDH shows an interesting variation with a different dosage of Ni(NO3)2. The Ni-Co LDH with integrated hollow structure exhibits superior electrochemical property among the obtained materials. The electrochemical tests revealed that the electrode display a specific capacity of 790Cg−1 at 2Ag−1 and a favourable rate capability. The integrated polyhedral hollow structure and the interlaced nanosheets make the Ni-Co LDH a highly promising material for hybrid supercapacitors.