In-situ preparation of nitrogen doped unimodal ultramicropores carbon nanosheets with ultrahigh gas selectivity

The development of simple and feasible methods to synthesize highly efficient adsorbents is the key to low-cost gas purification. Here we developed an in-situ amorphous cobalt template method based on the synergistic effect of precursor to synthesize nitrogen doped unimodal ultramicropores carbon nanosheets Co-NDPCs with high nitrogen content (up to 11.74%), large specific surface area (up to 1187 m² g⁻¹) and unimodal ultramicropore. As an adsorbent, the Co-NDPCs exhibit unprecedented C₂H₂, C₂H₆, C₃H₈ and CO₂ uptake capacities of 6.7, 5.9, 7.4 and 5.6 mmol g⁻¹, respectively, and the corresponding x/CH₄ and CO₂/N₂ IAST selectivities are as high as 75.3, 65.9.1743.6, 11.4 and 74.7 at 298 K and 1 bar. More importantly, this method effectively avoids the defects of traditional activation or template method, such as corrosiveness, poor safety and complicated process, indicating that Co-NDPCs is a promising adsorbent for CH₄/C₂H₂/C₂H₆/C₃H₈/CO₂/N₂ capture and separation.