Nitrogen-enriched carbon sheet for Methyl blue dye adsorption.

In this work, nitrogen-enriched carbon sheet (NECS) was successfully fabricated by using sodium gluconate as a carbon source via melamine assisted chemical blowing approach. The obtained material exhibits sheet-like morphology with ultra-thin thickness and has a high specific surface area of 604 m2g-1 and high nitrogen contents of 11.2 wt%. The NECS showed an excellent adsorption performance towards the removal of anionic dye Methyl blue (a-Mb). The adsorption of a-Mb onto NECS better fitted the Langmuir isotherm model with the highest adsorption capacity of 847 mg g-1. Interestingly, the NECS showed a pH-sensitive behavior towards the adsorption efficiency of a-Mb dye in which the adsorption capacity abruptly increased from 34 to 701 mg g-1 when the pH of the solution was decreased from 10 to 2. Furthermore, the adsorbed materials can be easily regenerated without obvious efficiency loss over a five adsorption-desorption cycles.