Enhancing Cr(VI) reduction and immobilization by magnetic core-shell structured NZVI@MOF derivative hybrids
Enhancing Cr(VI) reduction and immobilization by magnetic core-shell structured NZVI@MOF derivative hybrids
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DOI：
10.1016/j.envpol.2020.114021
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发表时间：
2020-05-01
影响因子：
8.9
通讯作者：
Hu, Xiaohong
中科院分区：
文献类型：
--
作者：
Fang, Ying;Wen, Jia;Hu, Xiaohong
Hexavalent chromium (Cr(VI)) has significantly threatened the environmental health because of its distinct toxicity. A novel magnetic core-shell structured NZVI@ZD composite was designed for simultaneous adsorption and reduction of Cr(VI). NZVI@ZD was synthesized by carbonization of the as-prepared core-shell structure NZVI@zeolitic imidazole framework-67 (ZIF-67). After carbonization, the original ZIF-67 shell shape was preserved well with marginal parts developing to graphitized carbon. Both cobalt (Co) and NZVI nanoparticles were finely dispersed in the porous ZIF-67 derivative (ZD). NZVI@ZD exhibited excellent removal performance for Cr(VI), owing to its high specific surface area and large pore size favorable for Cr(VI) adsorption and diffusion. The maximum adsorption capacity of NZVI@ZD for Cr(VI) was surprisingly as high as 226.5 mg g(-1), surpassing the pristine ZIF-67 (29.35 mg g(-1)) and NZVI@ZIF-67 (36.53 mg g(-1)). Zeta potential and X-ray photoelectron spectroscopy (XPS) spectra revealed that electrostatic attraction, reduction and precipitation might be involved in the Cr(VI) removal process by NZVI@ZD, resulting in the conversion of the adsorbed Cr(VI) to Cr(III) of lower toxicity and an eventual immobilization on the NZVI@ZD. The magnetic core-shell structured NZVI@ZD possessed superior adsorptive reactivity for Cr(VI) to most other traditional or newly reported materials, thus should be deemed highly efficient for Cr(VI)-contaminated wastewater treatment. (C) 2020 Elsevier Ltd. All rights reserved.
