Nickel–cobalt layered double hydroxide ultrathin nanoflakes decorated on graphene sheets with a 3D nanonetwork structure as supercapacitive materials

• The paper reported the microwave synthesis of nickel–cobalt layered double hydroxide/graphene composite.
• The novel synthesis method is rapid, green, efficient and can be well used to the mass production.
• The as-synthesized composite offers a 3D flowerclusters morphology with nanonetwork structure.
• The composite offers excellent supercapacitive performance.
• This study provides a promising route to design and synthesis of advanced graphene-based materials with the superiorities of time-saving and cost-effective characteristics.

The study reported a novel microwave heating reflux method for the fabrication of nickel–cobalt layered double hydroxide ultrathin nanoflakes decorated on graphene sheets (GS/NiCo-LDH). Ammonia and ethanol were employed as precipitant and reaction medium for the synthesis, respectively. The resulting GS/NiCo-LDH offers a 3D flowerclusters morphology with nanonetwork structure. Due to the greatly enhanced rate of electron transfer and mass transport, the GS/NiCo-LDH electrode exhibits excellent supercapacitive performances. The maximum specific capacitance was found to be 1980.7 F g−1 at the current density of 1 A g−1. The specific capacitance can remain 1274.7 F g−1 at the current density of 15 A g−1 and it has an increase of about 2.9% after 1500 cycles. Moreover, the study also provides a promising approach for the design and synthesis of metallic double hydroxides/graphene hybrid materials with time-saving and cost-effective characteristics, which can be potentially applied in the energy storage/conversion devices.

The microwave heating reflux approach was developed for the fabrication of nickel–cobalt layered double hydroxide ultrathin nanoflakes decorated on graphene sheets, in which ammonia and ethanol were used as the precipitator and medium for the synthesis. The obtained composite shows a 3D flowerclusters morphology with nanonetwork structure and largely enhanced supercapacitive performance.Figure optionsDownload as PowerPoint slide