In situ Carbothermal Synthesis of Nanoscale Zero-Valent Iron Functionalized Porous Carbon from Metal-Organic Frameworks for Efficient Detoxification of Chromium(VI)

Owing to the high toxicity of Cr-VI species to human health and the ecosystem, much attention has been paid to the development of efficient adsorbents for Cr-VI. Herein, MIL-100(Fe) was successfully utilized as a precursor for the carbothermal reductive synthesis of nanoscale zero-valent iron functionalized porous carbon (nZVI@C) for the effective removal of Cr-VI. The organic ligands in MIL-100(Fe) were transformed into a porous carbon matrix, whereas the Fe-O clusters were reduced in situ to nZVI owing to the strong reducibility of pyrolytic carbon. Additionally, the nZVI was distributed uniformly in the carbon support with a high loading and controllable particle size. Highly toxic Cr-VI species were efficiently degraded into less toxic Cr-III species at the nZVI reductive sites, and then the Cr-III species precipitated as (CrxFe1-x)(OH)(3) in the porous hybrids. The Cr-VI adsorption capacity of the developed nZVI@C reached 206 mg g(-1) under optimal conditions. Furthermore, the excellent magnetic performance of nZVI@C makes it convenient for Cr-VI remediation through simple magnetic separation. These outstanding characteristics indicate the promising potential of the developed material as an adsorbent for the efficient removal of Cr-VI from industrial wastewater.