Hydrogen storage in high surface area graphene scaffolds†
Abstract
Using an optimized KOH activation procedure we prepared highly porous graphene scaffold materials with SSA values up to 3400 m2 g−1 and a pore volume up to 2.2 cm3 g−1, which are among the highest for carbon materials. Hydrogen uptake of activated graphene samples was evaluated in a broad temperature interval (77–296 K). After additional activation by hydrogen annealing the maximal excess H2 uptake of 7.5 wt% was obtained at 77 K. A hydrogen storage value as high as 4 wt% was observed already at 193 K (120 bar H2), a temperature of solid CO2, which can be easily maintained using common industrial refrigeration methods.