Deionization using electrochemical redox reactions has potentially been the latest desalination technique with high salt removal capacity and lower energy cost due to high capacity of electrode materials and electrochemical energy release. Herein, we presented a metal-free continuous electrodialysis desalination technology, which could directly desalt feed water at high concentrations to drinking water level during continuous treatment with unlimited salt removal capacity. The device consists of a recirculating 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) stream between the flowing positive and negative electrodes in series and the salt feed stream. During the charging process, the flowing TEMPO was oxidized at the positive reservoir, where the anion in the feed was captured through the anion exchange membrane, whereas the TEMPO recovery at the negative reservoir drove the cation removal in the feed through the cation exchange membrane by its reduction. Due to the redox reaction of TEMPO between the cyclical flow electrode streams, it acts as a
Wang, J., Zhang, Q., Chen, F., Hou, X., Tang, Z., Shi, Y., … Li, L.-J. (2019). Continuous desalination with a metal-free redox-mediator. Journal of Materials Chemistry A, 7(23), 13941–13947. doi:10.1039/c9ta02594d
This project was supported by South China Normal University. F. C. thanks the support from Outstanding Young Scholar Project (8S0256), and the Scientific and Technological Plan of Guangdong Province (2018A050506078). This work is supported by the Project of Blue Fire Plan (No. CXZJHZ201708 and CXZJHZ201709). This work was supported by National Natural Science Foundation of China and Guangdong Province (U1601214, 51672090, 51372092, and 61575067), the Natural Science Foundation of Guangdong Province (2017A030310166), the Scientific and Technological Plan of Guangdong Province (2018B050502010, 2017B090901027). Y. S. acknowledges the support from the Key Project of Department of Education of Guangdong Province (2016KZDXM008). L. L. acknowledges the supports from University of New South Wales.