Activation was carried out in a conventional horizontal furnace
at 500 C for 2 h in inert atmosphere of nitrogen at standard temperature
and pressure (200 cm3 STP/min). The activation temperature
was reached at a heating rate of 10 C/min. The system was
then cooled down while maintaining the N2 flow. The resulting
carbon was washed in successive batches with aqueous HCl solution
until no Zn2+ (Zn2+ was detected by atomic absorption in the
filtrate) and then rinsed with distilled water until negative Cl
analysis. The carbon obtained is denoted as AC.