Metal–organic framework (MOF) as a template for syntheses of nanoporous carbons as electrode materials for supercapacitor

Five nanoporous carbons (NPCs) were prepared by polymerizing and then carbonizing carbon precursor of furfuryl alcohol accommodated in a porous metal–organic framework (MOF-5, [Zn4O(bdc)3], bdc = 1,4-benzenedicarboxylate) template. The Brunauer–Emmett–Teller (BET) surface areas for five NPC samples obtained by carbonizing at the temperatures from 530 to 1000 °C fall into the range from 1140 to 3040 m2 g−1 and the dependence of BET surface areas on carbonization temperatures shows a “V” shape. All the five NPC samples have a pore size distribution centered at about 3.9 nm. As electrode materials for supercapacitor, the NPC samples obtained at the temperatures higher than 600 °C display the ideal capacitor behaviors and give rise to almost constant specific capacitance (above 100 F g−1 at 5 mV s−1) at various sweep rates, which is associated with their mesoporous characteristics. However, the NPC sample with the highest BET surface area (3040 m2 g−1) obtained by carbonizing at 530 °C gives a unusually low capacitance (12 F g−1 at 5 mV s−1), which may be attributed to the poor conductivity of the carbon material due to the low carbonization temperature.