2 Experimental
2.1 Preparation of mesoporous carbon
Mesoporous carbon (MC) was prepared through a
template method[22]. 13 g Resorcinol (R) and 19 g
formaldehyde (F, 37 mass%) were directly dissolved in
deionized water with a molar ratio of 1:2. The silica sol with 7
nm silica (30 mass%, Aldrich) was added with a mass ratio of
silica to RF polymer of 1:1. The mixture was sealed in 100 mL
bottle, and then aged at 85 o
C for 5 d in a water-bath to obtain
hydrogel. After aged, the hydrogel was dried in air at 80 o
C for
24 h, and then carbonized under N2 flow at 800 o
C for 3 h with
a heating rate of 5 o
C/min. The resulting mesoporous carbon
was obtained through etching of silica in the carbonized
composites with NaOH for 24 h.