High-performance pseudocapacitive removal of cadmium via synergistic valence conversion in perovskite-type FeMnO3

Yingsheng Xu; Shuhong Xiang; Xinyuan Zhang; Hongjian Zhou; Haimin Zhang

doi:10.1016/j.jhazmat.2022.129575

High-performance pseudocapacitive removal of cadmium via synergistic valence conversion in perovskite-type FeMnO₃

J Hazard Mater. 2022 Oct 5:439:129575. doi: 10.1016/j.jhazmat.2022.129575. Epub 2022 Jul 12.

Authors

Yingsheng Xu¹, Shuhong Xiang¹, Xinyuan Zhang¹, Hongjian Zhou², Haimin Zhang³

Affiliations

¹ Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China; Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, PR China.
² Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China; Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, PR China. Electronic address: hjzhou@issp.ac.cn.
³ Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, PR China; Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, PR China. Electronic address: zhanghm@issp.ac.cn.

PMID: 35863230
DOI: 10.1016/j.jhazmat.2022.129575

Abstract

Cadmium pollution is a serious threat for the global drink water and natural environment. Herein, a poly-pyrrole coated dual-metal perovskite-type oxide FeMnO₃ (PFMO@PPy) was developed firstly as pseudocapacitive cathode for the reversible capture and release of cadmium ions by asymmetry pseudocapacitive deionization (APCDI) technology, extending the library of CDI electrodes. Our work highlighted several points: (i) PFMO@PPy achieved a maximum Cd-removal capacity of 144.6 mg g^-1, and maintained the retention rate of 93.4% after 15-cycle CDI process for up to 150 h, far beyond other previous work. (ii) PFMO@PPy showed the superior removal ratio (~90%) under different real water environments such as tap water, lake water and the groundwater. (iii) The superior Cd(II) electrosorption and desorption behavior is ascribed to the reversible synergistic valence conversion (Fe³⁺/Fe⁰ and Mn³⁺/Mn²⁺), which is confirmed by ex-situ XPS measurement and electrochemical tests. (iv) DFT calculations confirmed the synergistic effect from Mn and Fe elements in perovskite-type bimetallic oxide FeMnO₃. This study paves a new way for promising future applications of perovskite-type oxides containing dual Faradic redox-activity for wastewater treatment and environmental remediation.

Keywords: Cadmium pollution; Capacitive deionization; Perovskite-type oxides; Pseudocapacitance electrode; Synergistic valence conversion.