Abstract
Capacitive deionization (CDI) has emerged as a novel desalination technology due to its cleanliness and low energy consumption. Despite being based on the principle of an electric double layer for ion adsorption on porous carbon materials, the inevitable faradaic reaction and the existence of co-ion repulsion reduce the charge efficiency (CE), leading to a low salt adsorption capacity (SAC). Herein, an integrated membrane electrode (IME), prepared by spray-coating a thin layer of an ion exchange polymer on the activated carbon (AC) electrode, effectively improves the selectivity of the electrode to the counter-ion, resulting in a high CE and high SAC with good stability. The results show that the CE of CDI performed using IMEs is between 70% and 98% during multiple adsorption-desorption cycles, and the SAC is up to 14–20 mg g−1, which is much higher than CE (35–65%) and SAC (7–13 mg g−1) of traditional CDI with pristine AC electrodes. This study indicates that CDI using IMEs is advantageous for desalination with great application potential.
Original language | English |
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Article number | 114460 |
Journal | Desalination |
Volume | 491 |
DOIs | |
State | Published - 1 Oct 2020 |
Bibliographical note
Publisher Copyright:© 2020 Elsevier B.V.
Funding
This work was financially supported by National Natural Science Foundation of China (nos. 51678020 , 51761145047 ).
Funders | Funder number |
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National Natural Science Foundation of China | 51678020, 51761145047 |
Keywords
- Capacitive deionization
- Co-ion repulsion
- Integrated membrane electrode
- Ion exchange polymer
- Spray-coating