Chemical Blowing Approach for Ultramicroporous Carbon Nitride Frameworks and Their Applications in Gas and Energy Storage

A scalable, template‐free synthetic strategy is presented for the preparation of ultramicroporous carbon nitride frameworks (CNFs) through a chemical blowing approach by using ammonium chloride as blowing agent and hexamethylene tetraamine as the C and N precursor and a subsequent potassium hydroxide chemical activation is employed to obtain CNFs with surface areas up to 1730 m 2 g −1 along with a high nitrogen content of 13.3 wt%. CNFs showed CO 2 uptake capacities up to 5.74 mmol g −1 at 1 bar and 1.67 mmol g −1 at 0.15 bar, 273 K along with a very high CO 2 /N 2 selectivity. In addition, H 2 uptake capacity of 1.9 wt% and the isosteric heats of adsorption ( Q st ) value of 9.0 kJ mol −1 at zero coverage have been also observed. Moreover, the presence of nitrogen‐doped graphene walls in CNFs also facilitated their application as supercapacitors, with capacitance values up to ≈114 F g −…