Novel carbon molecular sieve membranes for CO2 separation derived from the zero-dimension carbon quantum dots doped polyimide

• The carbon quantum dots were applied as the new filler to prepare CMS membranes. • The nanopores structure was regulated by the carbon quantum dots introduction. • CO 2 /CH 4 separation properties of the CMS membranes were enhanced obviously. Carbon molecular sieve (CMS) membranes are very promising for efficient gas separation. In this work, a novel CMS membrane was constructed from the zero-dimension material doped polyimide precursor. The introduction of carbon quantum dots into the polyimide matrix precursor regulated the nanopores structure of the derived CMS membranes precisely for CO 2 separation. The PSD (pore size distribution) near 0.35 nm became narrower after the carbon quantum dots incorporation. And, the novel CMS membranes showed attracting enhancement of gas permeability (114.6 Barrer) and selectivity (94.7) for CO 2 /CH 4 separation simultaneously, which broke 2008 upper bound. Furthermore, the zero-dimension materials are the promising fillers to regulate the nanopores structure of the CMS membranes. The carbon quantum dots (CQDs) were introduced into polyimide precursor to regulate the nanopores structure of the derived carbon membranes.