Effective CO capture by in-situ nitrogen-doped nanoporous carbon derived from waste antibiotic fermentation residues.

It is of great environmental benefit to rationally dispose of and utilize antibiotic fermentation residues. In this study, oxytetracycline fermentation residue was transformed into an in-situ nitrogen-doped nanoporous carbon material with high CO adsorption performance by low-temperature pyrolysis pre-carbonization coupled with pyrolytic activation. The results indicated the activation under mild conditions (600 °C, KOH/OC = 2) was able to increase micropores and reduce the loss of in-situ nitrogen content. The developed microporous structure was beneficial for the filling adsorption of CO, and the in-situ nitrogen doping in a high oxygen-containing carbon framework also strengthened the electrostatic adsorption with CO. The maximum CO adsorption reached 4.38 mmol g and 6.40 mmol g at 25 °C and 0 °C (1 bar), respectively, with high CO/N selectivity (32/1) and excellent reusability (decreased by 4% after 5 cycles). This study demonstrates the good application potential of oxytetracycline fermentation residue as in-situ nitrogen-doped nanoporous carbon materials for CO capture.