【Frontiers of Materials Science】A two-step approach to synthesis of Co(OH)2/γ-NiOOH/reduced graphene oxide nanocomposite for high performance supercapacitors
writer：Ke Zhan, Tong Yin, Yuan Xue, Yinwen Tan, Yihao Zhou, Ya Yan, Bin Zhao*
keywords：Co(OH)2, rGO, supercapacitors
source：期刊
specific source：Frontiers of Materials Science, 2018, 12: 273–282.
Issue time：2018年
A two-step approach was reported to fabricate cobaltous hydroxide/γ- nickel oxide hydroxide/reduced graphene oxide (Co(OH)2/γ-NiOOH/RGO) nanocomposites on nickel foam by combining the reduction of graphene oxide with the help of reflux condensation and the subsequent hydrothermal of Co(OH)2 on RGO. The microstructural, surface morphology and electrochemical properties of the Co(OH)2/γ-NiOOH/RGO nanocomposite were investigated. The results showed that the surface of the first-step fabricated γ-NiOOH/RGO nanocomposites was uniformly coated by Co(OH)2 nanoflakes with lateral size of tens of nm and thickness of several nm. Co(OH)2/γ-NiOOH/RGO nanocomposite demonstrated a high specific capacitance (745 mF/cm2 at 0.5 mA/cm2) and a cycling stability of 69.8% after 1000 cycles at 30 mV/cm2. γ-NiOOH/RGO//Co(OH)2/γ-NiOOH/RGO asymmetric supercapacitor was assembled, and maximum gravimetric energy density of 57.3 W?h/kg and power density of 66.1 kW/kg were achieved. The synergistic effect between the highly conductive graphene and the nanoflake Co(OH)2 structure was responsible for the high electrochemical performance of the hybrid electrode. It is expected that this research could offer a simple method to prepare graphene-based electrode materials.