ZIF-derived in situ nitrogen decorated porous carbons for CO2 capture

Various N-doped hierarchical porous carbons were prepared by using a new mixed-ligand ZIF (zeolitic imidazolate framework) (JUC-160) as the precursor in a one-step synthetic route without any additional carbon sources or purification steps. The effect of the ZIF precursor crystal size on the textural properties of the derived porous carbons was systematically studied. Microporosity was dominant in micron-sized JUC-160 crystal derived porous carbons, while more mesopore volume was present in porous carbons obtained from nanometre-sized JUC-160 crystals. The mJUC160-900 sample, which had a high nitrogen content and micropore volume, exhibited the highest CO2 uptake, which is 5.50 and 3.50 mmol g(-1) at 273 and 298 K, respectively. Moreover, the analysis based on the ideal adsorbed solution theory (IAST) exhibited a high adsorption selectivity for CO2/N-2 at 298 K and 1 bar (S-ads = 29).