Graphitic N-Rich Graphene for Nonradical Peroxymonosulfate Activation

Nitrogen-doped graphene has been regarded as one of the most promising materials for nonradical peroxymonosulfate (PMS) activation. However, facile construction of nitrogen-doped graphene and systematic investigation of its nonradical PMS activation in a practical environment still far lag behind. Herein, graphitic N-rich graphene was prepared by one-step pyrolysis of urea. The obtained urea-derived graphitic N-rich graphene (UGNG) possessed a high N content of 12.12 at. % and a graphitic N proportion of 41.12%, giving a high graphitic N content of 4.98 at. %. We confirmed that PMS donated electrons to the graphitic N in UGNG, resulting in the cleavage of PMS to singlet oxygen for nonradical oxidation. The turnover frequency for the oxidation reached the highest value of 10.5 min(-1). Also, the reaction could be conducted in a wide temperature (5-45 degrees C) range, even with the existence of common matrix species and different natural water matrixes. This work presented the direct conversion of N-rich organic urea to UGNG and systematically investigated its nonradical PMS activation, which is believed to be helpful to its further practical use.