Preparation of 2D nitrogen-doped magnetic Fe3C/C by in-situ self-assembled double-template method for enhanced removal of Cr(VI)

• Published in: Environmental pollution (1987) 2020-08, Vol.263, p.114374-114374, Article 114374
• Main Authors: Su, Qiaohong, Su, Zhi, Xie, Wenyu, Tian, Chen, Su, Xintai, Lin, Zhang
• Format: Article
• Language: English
• Subjects: Cr(VI) removal; Iron carbide; Magnetic porous carbon; Nitrogen doped; Potassium humate
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2020.114374

Porous carbon, which can be functionalized, is considered as a potential carbon material. Herein, two-dimensional (2D) nitrogen-doped magnetic Fe3C/C (NMC) was prepared by a simple carbonization method using potassium humate (HA-K) as raw material. Remarkably, two templates, g-C3N4 and KCl, were formed in situ during the carbonization process, which provide the necessary conditions for the formation of 2D NMC. The NMC was comprehensively studied by different characterization methods. The results show that NMC has a large surface area and mesoporous structure. The prepared NMC-0.50 was used to test the removal performance of Cr(VI). The effects of pH value, coexisting ions and time on Cr(VI) removal performance were investigated, and the adsorption kinetics, isotherm and thermodynamics were studied. The results showed that the adsorption isotherm model of NMC-50 accorded with the Langmuir model, and the maximum adsorption capacity was 423.73 mg g−1. The reaction mechanism of Cr(VI) is adsorption and redox reaction. In addition, NMC-0.50 exhibit high selectivity, separability and regeneration performance. A convenient means for the synthesis of NMC was designed in this work, and demonstrate that NMC has practical value as an adsorbent. The reaction mechanism of Cr(VI) is redox reaction and adsorption behavior, and the redox reaction is dominant. [Display omitted] •Synthesis of 2D nitrogen-doped magnetic Fe3C/C by one-step carbonization.•In situ formation of double templates during carbonization.•The adsorption of Cr(VI) is achieved via redox reactions and adsorption process.•2D nitrogen-doped magnetic Fe3C/C has maximum adsorption capacity (423.73 mg g−1) for Cr(VI). The 2D nitrogen-doped magnetic Fe3C/C was applied to efficiently adsorb Cr(VI).