Nitrogen-containing nanoporous carbons with high pore volumes from 4-(4-nitrophenylazo)resorcinol by a Mg(OH)2-assisted template carbonization method

Abstract

Producing nanoporous carbons that possess high porosity and superior electrochemical performance is a challenge for scientists. In this work, a simple and efficient template carbonization method, without any physical/chemical activation treatment, has been implemented to produce nanoporous carbons doped with nitrogen species. 4-(4-Nitrophenylazo)resorcinol serves as a carbon/nitrogen source and Mg(OH)₂ as a hard template. All resultant carbon samples are amorphous, highly porous in nature and display sheet-like nanostructures. The carbon-1:3-L sample whose precursor is obtained by solution method exhibits better porosity, and larger nitrogen content, than those obtained by solid state method (the carbon-1:3-S sample). The carbon-1:3-L sample exhibits large specific surface area (S_BET) of 1427.7 m² g⁻¹, and high total pore volume (V_T) of 5.91 cm³ g⁻¹, whereas those of the carbon-1:3-S sample are of 1036.6 m² g⁻¹ and 4.76 cm³ g⁻¹, respectively. Notably, the present pore volumes are much higher than most of the previously reported for nanoporous carbons. As a consequence, the carbon-1:3-L sample delivers superior electrochemical behaviors, whose specific capacitance reaches up to 378.5 F g⁻¹ when measured at 1 A g⁻¹ in a three-electrode system, compared with that of 263.4 F g⁻¹ of the carbon-1:3-S sample. The present Mg(OH)₂-assisted template carbonization method is simple and easy to operate, indicating its potential application for producing nanoporous carbons.