A General Synthetic Strategy toward Highly Doped Pyridinic Nitrogen-Rich Carbons

Doping carbon materials with p-block elements such as nitrogen is an effective approach to tune electronic properties of the framework and can endow the host's new characters. To date, highly doped carbons with tunable nitrogen speciation are still less explored due to the grand challenge in fabrication; for example, the typical synthesis based on the pyrolysis of nitrogen-containing precursors shows a trade-off between the total nitrogen content and the carbonization temperature, limiting the value to approximate to 12 wt% at 1073 K. Herein, intensifying ring opening of cross-linked polymers through controlled pre-oxidation followed by conventional pyrolysis is demonstrated as an elegant method to circumvent this challenge. In addition to fine tunability at different nitrogen speciation, this strategy can increase the nitrogen content by two- to threefold (maximum approximate to 22 wt%) and shows general viability in six different N-bearing (co)polymers. The highly doped pyridinic nitrogen-rich carbons show i) a remarkable capacity of 879 mAh g(-1)at 0.1 A g(-1)and excellent cycling performance in lithium ion batteries, and ii) significantly boosted catalytic performance in the selective oxidation of diverse substrates. Therefore, this facile synthetic strategy and the tunability at nitrogen functionalities will greatly broaden the applications of this new class of functional materials.

Automated summary

The study demonstrates a method to prepare highly nitrogen-doped carbon materials by intensifying ring opening of cross-linked polymers through controlled pre-oxidation followed by conventional pyrolysis, leading to a two- to threefold increase in nitrogen content with great tunability. These carbon materials exhibit excellent performance in lithium ion batteries and catalytic reactions.