Efficient removal of metal ions by capacitive deionization with straw waste derived graphitic porous carbon nanosheets

Hui Wang, Tingting Yan, Junjie Shen, Jianping Zhang, Liyi Shi, Dengsong Zhang

Research output: Contribution to journalArticle

15 Citations (Scopus)
29 Downloads (Pure)

Abstract

Capacitive deionization (CDI) is considered to be an energy-efficient and cost-effective technology for ion removal from saline or waste water. However, its implementation remains challenging due to low ion adsorption capacity of the commonly used electrode materials. It is thus desirable to develop highly efficient CDI electrode materials for ion removal. Herein, graphitic porous carbon nanosheets (GPCSs) were originally prepared from straw waste via a combined activation and graphitization process. Being composed of graphitic carbon sheets with abundant pores in the framework, the obtained GPCSs had a large specific surface area and good conductivity and wettability, which can provide sufficient adsorption sites and promote efficient ion transport. The GPCS electrodes presented a higher specific capacitance, good stability and low inner resistance in electrochemical tests. Moreover, the GPCSs showed a high deionization capacity of 19.3 mg g-1 at 1.2 V in a 500 mg L-1 NaCl solution. Repeated adsorption-desorption experiments demonstrated the good regeneration performance of the GPCS electrodes. Furthermore, the removal efficiency towards Cd2+, Ni2+ and Cu2+ of the GPCS electrodes is 91.5%, 97.0% and 100% at 1.2 V in a 100 mg L-1 CdCl2, NiCl2 or CuCl2 solution, respectively. This work offers a promising solution to efficient removal of ions from saline or waste water and a new route to the utilization of straw waste.

Original languageEnglish
Pages (from-to)317-326
Number of pages10
JournalEnvironmental Science: Nano
Volume7
Issue number1
Early online date12 Dec 2019
DOIs
Publication statusPublished - 31 Jan 2020

ASJC Scopus subject areas

  • Materials Science (miscellaneous)
  • Environmental Science(all)

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