Nitrogen doped tubular magnetic carbons embedded with nickel nanoparticles (Ni@NTMCs) were prepared via a simple pyrolysis process and employed as the effective adsorbents for the Cr(VI) removal. Ni@NTMCs with as high as 10.63 at.% N doping exhibited the excellent Cr(VI) removal capacities of 24.4 and 250 mg g-1 in neutral and acidic solution, respectively. Adsorption kinetics and isotherm study revealed that the monolayer chemical adsorption was the rate-controlling step for the Cr(VI) removal. The high removal performance can be ascribed to the combination of adsorption and reduction reaction between Cr(VI) ions, and Ni nanoparticles. N dopant and edge carbons acted as the Cr(VI) adsorption site. The surface Ni nanoparticles mainly made contributions to the reduction process. The embedded Ni nanoparticles steadily provided magnetism for the separation and helpful for the recycles stability, showing a high acid corrosion resistance in this study.

中文翻译：

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通过将镍纳米颗粒掺入氮掺杂的管状碳中进行环境修复，具有耐本酸和高去除性能。

通过简单的热解工艺制备了嵌入镍纳米颗粒（Ni @ NTMCs）的氮掺杂管状磁性碳，并将其用作去除Cr（VI）的有效吸附剂。高达10.63 at。％N掺杂的Ni @ NTMC在中性和酸性溶液中分别具有24.4和250 mg g-1的优异的Cr（VI）去除能力。吸附动力学和等温线研究表明，单层化学吸附是去除Cr（VI）的速率控制步骤。高去除性能可以归因于Cr（VI）离子与Ni纳米粒子之间的吸附和还原反应的结合。N掺杂剂和边缘碳充当Cr（VI）吸附位点。表面镍纳米粒子主要为还原过程做出了贡献。