A comprehensive review of capacitive deionization technology with biochar-based electrodes: Biochar-based electrode preparation, deionization mechanism and applications. (November 2022)

• Record Type: Journal Article
• Authors: Chu, Meile; Tian, Weijun; Zhao, Jing; Zou, Mengyuan; Lu, Zhiyang; Zhang, Dantong; Jiang, Junfeng
• Is Part Of: Chemosphere. Volume 307:Part 3(2022)
• Publication Date: 2022-11
• Subjects: Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.136024
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The recently developed techniques for desalination and wastewater treatment are costly and unsustainable. Therefore, a cost-effective and sustainable approach is essential to achieve desalination through wastewater treatment. Capacitive deionization (CDI), an electrochemical desalination technology, has been developed as a novel water treatment technology with great potential. The electrode material is one of the key factors that promotes the development of CDI technology and broadens the scope of CDI applications. Biochar-based electrode materials have attracted increasing attention from researchers because of their advantages, such as environmentally friendly, economical, and renewable properties. This paper reviews the methods for preparing biochar-based electrode materials and elaborates on the mechanism of CDI ion storage. We then summarize the applications of CDI technology in water treatment, analyze the mechanism of pollutant removal and resource recovery, and discuss the applicability of different CDI configurations, including hybrid CDI systems. In addition, the paper notes that environmentally friendly green activators that facilitate the development of pore structure should be developed more often to avoid the adverse environmental impact. The development of ion-selective electrode materials should be enhanced and it is necessary to comprehensively assess the impact of heteroatoms on selective ion removal and CDI performance. Electrooxidation of organic pollutants should be further promoted to achieve organic degradation by extending to redox reactions. Graphical abstract: Image 1 Highlights: Activation, templating, heteroatom doping and metal oxide loading have been shown to be effective means of improving the electrochemical properties of biocarbon-based materials. The ion storage mechanism of CDI involves EDL ion storage and Faraday pseudocapacitance storage. The applicability of CDI technology in the field of water treatment has been proven. Electrooxidation of organic pollutants should be further promoted to achieve simultaneous organic degradation by extending to redox reactions.