Preparation of β-Co(OH)2 nanosheets for pseudocapacitive electrode via cathode glow discharge electrolysis
摘要
β-Co(OH)2 nanosheets were prepared in NaNO3 solution by cathode glow discharge electrolysis (CGDE) technique, in which Co sheet and Pt needle were regarded as anode and cathode, respectively. The formation mechanism of β-Co(OH)2 was discussed in detail, and the electrochemical performance was investigated as an electrode material for the pseudocapacitor. The results showed that the obtained β-Co(OH)2 has a single phase of the hexagonal brucite-like nanosheets with an angle of adjacent edges of 120°, side length of 400–500 nm, and thickness of 10-20 nm. The average pore size and specific surface area are 33.1 nm and 122.1 m2 g−1, respectively. The β-Co(OH)2 nanosheets exhibit a high specific capacitance of 335 F g−1 and excellent capacity retention of 77.1% after 3000 charge-discharge cycles at 1 A g−1. CGDE offers a simple, fast, highly effective, and green strategy for the preparation of β-Co(OH)2 nanosheets. The prepared β-Co(OH)2 nanosheets can be used as an alternative electrode material for supercapacitors.
Graphical Abstract