Nitrogen-doped carbon materials with cubic ordered mesostructure: low-temperature autoclaving synthesis for electrochemical supercapacitor and CO2 capture

Abstract

Nitrogen doped ordered mesoporous carbons (NOMCs) with a 3-D body-centered cubic pore structure with uniform pore size of 2.9–3.0 nm and high BET surface area of 583–847 m² g⁻¹ have been synthesized by means of a facile and efficient low-temperature autoclaving route under basic conditions, in which triblock copolymer F127 was used as the template, and resorcinol/hexamethylenetetramine as the carbon precursor. The effect of synthesis parameters including the autoclaving temperature and autoclaving treatment time was investigated in detail. It is found that NOMCs with cubic Imm structure can be produced at the autoclaving temperature of 60 °C and autoclaving treatment time of ≥2 d. Benefiting from the unique features of high surface area, nitrogen doping, uniform and uninterrupted mesopores and rich microporosity, these NOMCs for supercapacitors exhibit high capacitance of 193 F g⁻¹ at 1.0 A g⁻¹, high rate capacity (90% capacitance retention at 10 A g⁻¹) and good cycling stability (99.1% capacity retention after 1000 cycles at 1.0 A g⁻¹) in 6 M KOH aqueous solution and good cycling stability with specific capacitance retention over 500 cycles. Moreover, the NOMCs also show excellent CO₂ capture properties with a capacity of 4.7 and 3.5 mmol g⁻¹ at 0 and 25 °C, respectively. It is revealed that both textural and surface chemistry properties influenced the CO₂ capture performance of the resultant NOMCs adsorbents.