Synthesis of mesoporous Co(OH)2 nanocubes derived from Prussian blue analogue and their electrocapacitive properties

Taking Prussian blue analogue (Co-3[Co(CN)(6)](2)) nanocubes as precursor, mesoporous Co(OH)(2) nanocubes were synthesized by simply reacting Co-3[Co(CN)(6)](2) nanocubes with NaOH aqueous solution. Their morphology and microstructures were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and micropore and chemisorption analyzer. Electrocapacitive properties of mesoporous Co(OH)(2) nanocubes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge method. Results show that the mesoporous Co(OH)2 nanocubes have mainly mesoporous structure with the specific surface area as high as 297 m(2) g(-1), a high specific capacitance of 420 F g(-1) at 1 A g(-1) and excellent rate performance (80.9% retention from 1 A g-1 to 10 A g-1). In addition, the capacitance of the mesoporous Co(OH)(2) nanocubes retained 82.4% of the initial value after 5000 cycles even at a high current density of 10 Ag-1. These indicates that the mesoporous Co(OH)(2) nanocubes are good candidates for supercapacitor electrode material. (C) 2017 Elsevier B.V. All rights reserved.