Hollow nanohexagons with a core–shell structure have been synthesized from a mixture of Ni and Co hydroxide by a mild wet chemical approach. Ni(OH)2@Co(OH)2nanohexagons with controllable sizes of about 200 nm, morphology and structure are obtained. Comprehensive microstructure analysis reveals that the Ni(OH)2 and Co(OH)2components are single-crystalline. The surfaces of the nanohexagons are smooth and their inner facets can be controlled to be parallel to the outer facets or rotated by 30°. A growth mechanism depending on the N2H4·H2O content and reaction temperature has been proposed to explain the different structures. The parallel inner facets tend to form with higher amounts of N2H4·H2O while the rotated ones tend to form at higher temperature. The specific capacitance of the hollow nanohexagon is about 369 F/g, which can be remained as high as 96.4% after 2500 cycles at current density of 1 A/g.
以上工作发表在 Nano Energy Volume 5, April 2014, Pages 52–59