Double-photoelectrode redox desalination of seawater

Xing Wang; Mengjun Liang; Jiancong Zhang; Xuncai Chen; Mono Zaw; Than Zaw Oo; Nyein Wint Lwin; Su Htike Aung; Yuan Chen; Fuming Chen

doi:10.1016/j.watres.2023.120051

Double-photoelectrode redox desalination of seawater

Water Res. 2023 Jul 1:239:120051. doi: 10.1016/j.watres.2023.120051. Epub 2023 May 6.

Authors

Xing Wang¹, Mengjun Liang², Jiancong Zhang³, Xuncai Chen⁴, Mono Zaw⁵, Than Zaw Oo⁵, Nyein Wint Lwin⁵, Su Htike Aung⁵, Yuan Chen⁶, Fuming Chen⁷

Affiliations

¹ School of Electronics and Information Engineering, South China Normal University, Foshan 528225, PR China; School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, PR China.
² School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, PR China; Hubei Key Laboratory for High-Efficiency Utilization of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, PR China.
³ School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, PR China.
⁴ Guangzhou Key Laboratory of Forensic Multi-Omics for Precision Identification, School of Forensic Medicine, Southern Medical University, Guangzhou 510515, PR China.
⁵ Department of Physics, Materials Research Laboratory, University of Mandalay, Mandalay 05032, Burma.
⁶ School of Chemical and Biomolecular Engineering, The University of Sydney, Darlington, NSW 2006, Australia. Electronic address: yuan.chen@sydney.edu.au.
⁷ School of Electronics and Information Engineering, South China Normal University, Foshan 528225, PR China; School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, PR China. Electronic address: fmchen@m.scnu.edu.cn.

PMID: 37182310
DOI: 10.1016/j.watres.2023.120051

Abstract

High energy consumption and low salt removal rate are key barriers to realizing practical electrochemical seawater desalination processes. Here, we demonstrate a novel solar-driven redox flow desalination device with double photoelectrodes to achieve efficient desalination without electrical energy consumption. The device consists of three parts: one photoanode unit, one photocathode unit, and one redox flow desalination unit sandwiched between the two photoelectrode units. The photoelectrode units include a TiO₂ photoanode and a NiO photocathode sensitized with N719 dye, triiodide/iodide redox electrolyte, and graphite paper integrated electrodes decorated with 3,4-ethylene-dioxythiophene. Two salt feeds are located between two ferro/ferricyanide redox flow chambers. Under light illumination, high-quality freshwater is obtained from brackish water containing different concentrations of NaCl from 1000 to 12,000 ppm with a high NaCl removal rate. The device can work in multiple desalination cycles without significant performance declines. Furthermore, natural seawater with an ionic conductivity of 53.45 mS cm^-1 is desalinated to freshwater. This new design opens opportunities to realize efficient and practical solar-driven desalination processes.

Keywords: Dye-sensitized solar cell; NiO photocathode; Redox flow desalination; TiO(2) photoanode.

MeSH terms

Oxidation-Reduction
Seawater
Sodium Chloride*
Sunlight
Water Purification*

Substances

Sodium Chloride