Melamine derived nitrogen-doped carbon sheet for the efficient removal of chromium (VI)

A novel nitrogen-doped carbon sheet (NDCS) utilized for Cr (VI) elimination from wastewater, was fabricated. The NDCS is fabricated by a very easy approach, via the self-assembly process of melamine and citric acid as nitrogen and carbon precursors respectively. Through the self-assembly of citric acid and melamine in hot water and their subsequent carbonization nitrogen-doped carbon sheet was obtained. The obtained carbon sheet exhibited a good removal performance of Cr (VI) 432 mg g−1 according to the Langmuir model at an optimal pH of 3.0. The aforementioned enhanced removal efficiency can be put forth to the doped nitrogen contents in the material, which causes electrostatic attraction between ions of the chromium and the protonated nitrogen at low pH. The obtained carbon sheet provides an easy and environmentally friendly approach to fabricate nitrogen-doped carbon sheet, which elucidates great significance to be applied as an adsorbent for practical application in the wastewater treatment. [Display omitted] •Low cost adsorbents with high capacity are desired for heavy metals removal.•Nitrogen doped carbon sheet were prepared via self assembly of citric acid and melamine•432 mg g−1 Cr (VI) adsorption capacity was achieved by Langmuir fitting.•Nitrogen doped carbon is an efficient adsorbent for the removal of Cr (VI) ions.