Controllable synthesis of a hollow core-shell Co-Fe layered double hydroxide derived from Co-MOF and its application in capacitive deionization

Zhe Li; Shudi Mao; Ying Yang; Zhuo Sun; Ran Zhao

doi:10.1016/j.jcis.2020.11.091

Controllable synthesis of a hollow core-shell Co-Fe layered double hydroxide derived from Co-MOF and its application in capacitive deionization

J Colloid Interface Sci. 2021 Mar:585:85-94. doi: 10.1016/j.jcis.2020.11.091. Epub 2020 Nov 25.

Authors

Zhe Li¹, Shudi Mao¹, Ying Yang¹, Zhuo Sun², Ran Zhao³

Affiliations

¹ Engineering Research Center for Nanophotonics & Advanced Instrument, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 500 Dongchuan Road, 200241 Shanghai, China.
² Engineering Research Center for Nanophotonics & Advanced Instrument, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 500 Dongchuan Road, 200241 Shanghai, China; East China Normal University-University of Alberta Joint Institute of Advanced Science and Technology, 3663 North Zhongshan Road, 200062 Shanghai, China.
³ Engineering Research Center for Nanophotonics & Advanced Instrument, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 500 Dongchuan Road, 200241 Shanghai, China; East China Normal University-University of Alberta Joint Institute of Advanced Science and Technology, 3663 North Zhongshan Road, 200062 Shanghai, China. Electronic address: rzhao@phy.ecnu.edu.cn.

PMID: 33279708
DOI: 10.1016/j.jcis.2020.11.091

Abstract

Capacitive deionization (CDI) is considered one of the most promising desalination technologies for obtaining fresh water from saline water. In this work, we synthesized a hollow core-shell Co-MOF@Fe/Co-LDH (Co-Fe-LDH) material by developing a strategy to simultaneously grow Co/Fe-LDH on the surface of a Co-MOF precursor in situ. Owing to the increase in the specific surface area of the hollow structure and the Faradaic process of a layered double hydroxide (LDH), the Co-Fe-LDH material exhibits high electrical double layer (EDL) capacitance and pseudocapacitance, which significantly improves the salt adsorption of the material during CDI (34.2 mg/g in a 600 mg/L NaCl solution at 1.2 V). The adsorption for NaCl in this work is approximately 2.5 times the maximum salt adsorption capacity (SAC) of LDH materials applied in nonmembrane CDI (NMCDI). This work may provide a promising model for the application of hollow LDH materials that exhibit pseudocapacitance in CDI.

Keywords: Capacitive deionization; Hollow structure; Pseudocapacitance.