Coupling template nanocasting and self-activation for fabrication of nanoporous carbon

Hierarchical nanoporous carbon (NPC) with great surface area and developed pore size distribution has been intently concerned. Herein, we report a facile method coupling template nanocasting and self-activation to fabricate nanoporous carbon with continuous micro, meso and macro pores, in which CaCO₃ acted as template and activation reagent while the flour was the carbon precursor. Effects of mass ratio of CaCO₃ to flour and carbonized temperature on the pore structures of NPC were investigated by nitrogen adsorption-desorption isotherms and SEM analysis. Another kind of carbon was prepared by directly mixed powder CaCO₃ with flour carbonized at 800 °C (NPC-p) to comparatively investigate the pore fabricating mechanism. Results shown that carbonized at 800 °C was favorable to fabricate the continuous macro, meso and micro pores. The resulted NPC in a mass ratio of 1 to 2 had the considerable S_BET and V_T of 575.4 m²/g and 0.704 cm³/g, respectively. Only surface activation was observed for NPC-p. Nanocasting of the powder CaCO₃ contributed to fabricate macropores and the CO₂ activation contributed to meso- and micropores. Coupling activation and nanocasting effect due to the decomposition of CaCO₃ template into CO₂ and CaO was ascribed to synthesize the nanoporous carbon.