Chemical modification of carbon particles to enhance the electrosorption of capacitive deionization process

Autor: Chen Dou, Shengyong Zhai, Yiyang Liu, Peng Chen, Di Yin, Guangtuan Huang, Lehua Zhang
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of Water Reuse and Desalination, Vol 10, Iss 1, Pp 57-69 (2020)
Druh dokumentu: article
ISSN: 2220-1319
2408-9370
DOI: 10.2166/wrd.2020.052
Popis: Activated carbon particle electrodes modified by oxygen or nitrogen groups could be promising electrode candidates for capacitive deionization (CDI) processes. In this work, activated carbon particle electrodes were modified by phosphoric acid, nitric acid, urea, melamine, and zinc chloride to enhance desalination of an aqueous electrolytic solution. The modified activated carbon particles were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller measurements and electrochemical scanning. The electrodes with oxygen or nitrogen groups on the surface exhibited a much higher desalination capacity and charge efficiency than those without any surface modification. Particularly, the activated carbon particle electrode modified by phosphoric acid exhibited a desalination capacity of 15.52 mg/g at 1.4 V in 500 mg/L NaCl solution, which was approximately eight times that of the unmodified electrode (2.46 mg/g). The enhancement was attributed to a higher specific capacitance, a lower electrochemical impedance and an increase in oxygen or nitrogen-containing groups on the surface.
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