| Althouth the theoretical specific capacitance of nickel and cobalt double hydroxide（Ni/Co-DH） is relatively high, low electron conductivity restricts their practical applications in high-performance supercapacitors. In this paper, we have tried to prepare nickel/cobalt double hydroxide composite containing reduced graphene oxide（Ni/Co-DH-RGO） and to fabricate Ni/Co-DH with high specific surface to solve the above issue.（1）Ni/Co-DH-RGO:Generally, to achieve high electron cond uctivity, graphene oxide（GO） is firstly reduced in a separate device before forming a composite with metallic hydroxide. However, the separate reduction process can decrease carboxylic acid and hydrox yl groups in GO, resulting in unavoidable aggregation of GO and i n turn the difficulty in loading metallic hydroxide. In this work, we have tried to hydrothermal one-step prepare Ni/Co-DH-RGO. Hexa methylene tetramine（HMT） can be hydrolyzed into ammonia and f ormaldehyde in hydrothermal reactor（autoclave）, which can act as a homogeneous precipitating agent and a reductant, respectively. Asa result, not only can RGO be easily obtained and the aggregation of GO be alleviated, but also it is not necessary to add alkali drop by drop for preparing metallic hydroxide. According to the impeda nce plots, the calculated charge-transfer resistances of Ni/Co-DH-RG O and Ni/Co-DH electrodes are 4.21 and 14.01?, respectively.The a s-prepared Ni/Co-DH-RGO has a specific capacitance of 2120 F g-1at the current density of 1A g-1.（2）Ni/Co-DH: Cetyltrimethylammonium bromide（CTAB） is the cationic surfactant. We have tried to prepare Ni/Co-DH by hydrothermal one-step process accompanied with using both CTAB as shape-directing agent and HMT as homogeneous precipitation agent. Ni/Co-DH has a BET area of 93.6 m2g-1 and a mesopore size of 13.4nm. Ni/Co-DH takes on layered structure, which leads to a maximum specific capacitance of1902 F g-1 at the current density of 1A g-1. |
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