Assembly of Graphene Sheets into Hierarchical Structures for High-Performance Energy Storage The graphene oxide (GO) solution was subjected to another 30 min of centrifugation at 14000 rpm. We then adjusted the pH value of the top clean solution to about 9 with 1 mol/L NaOH aqueous solution. After that, we titrated the GO aqueous solution with 1 mg/mL DODA.Br chloroform solution. When the color of aqueous solution changed to light yellow, we stopped adding DODA.Br chloroform solution. The organic phase was then separated and washed by DI water. Finally, the composite material GO/DODA was obtained by evaporating the chloroform to dryness. Typically, the honeycomb thin films were prepared by direct casting GO/DODA complex chloroform solution (1 mg/mL) onto the glass substrates under a moist airflow (relative humidity ca. 85%). The brown thin films covering an area of ca. 2 cm2 were left behind after the complete evaporation of the solvent and water within 30-60 s.The control experiments without humid airflow had been performed in the desiccators (relative humidity ca. 30%) and no macroporous structures developed, leaving only unpatterned flat films as a result. To keep the macroporous structure, we used the hydrazine vapor to reduce the film. The films were then put into the autoclave, and then 10 μL of hydrazine monohydrate was added into the autoclave. Finally, the autoclave was heated at 90 ℃ for 16 h to get the reduced films.
标签: 14000
