Covalent-organic framework derived nitrogen-enriched carbon: A remarkable adsorbent to remove 4-nitrophenol from water

•N-enriched carbons were first prepared via two-step carbonization of a COF, SNW-1.•One carbon called CDC(800) had a very high Qo, 1190 mg/g of p-nitrophenol at pH 7.•The Qo is 6 times that of activated carbon and higher than any other reported results.•CDC(800) was recyclable and can be a competitive adsorbent to remove pNP from water.