Controllable nitrogen-doping of nanoporous carbons enabled by coordination frameworks

Doping nitrogen into nanoporous carbons is of great significance in various applications. However, in situ synthesis of N-doped nanoporous carbons with controllable/predictable N configurations remains a challenge. On the basis of first-principles calculations, we developed a temperature-control strategy to tailor the N configurations in nanoporous carbons based on the different thermal stabilities of the N dopants. By annealing the coordinated 2-methylimidazole molecules in a range of temperatures, the content of the N dopants in the obtained nanoporous carbons can be controlled, eventually leading to a maximized percentage of pyridinic-N. The K-ion storage capacity of the N-doped nanoporous carbons showed a strong correlation with the N configurations according to a carbon/K half-cell test. The nanoporous carbon with the maximum percentage of pyridinic-N showed a remarkable rate performance and cycling stability, matching with the prediction of the first-principles calculations.