Metal cobalt dot-doped carbon structures with specific exposure surfaces for high-performance capacitive deionization

• Published in: Journal of environmental chemical engineering 2024-04, Vol.12 (2), p.112189, Article 112189
• Main Authors: Cao, Yiyun, Yan, Lvji, Wu, Bichao, Wei, Dun, Ouyang, Baixue, Chen, Peng, Zhang, Tingzheng, Wang, Haiying, Huang, Lei
• Format: Article
• Language: English
• Subjects: Capacitive deionization; Chlorine; Cobalt; Heavy metals; Metal-organic framework
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2024.112189

The contamination of aquatic ecosystems has resulted in significant health and environmental ramifications. The removal of pollutants from wastewater poses a significant challenge for water purification, requiring innovative and efficient technologies to ensure the protection of human health and the environment. Recently, capacitive deionization (CDI) has garnered significant attention as a cost-effective and user-friendly water purification process. The development of high-performance electrode materials plays a pivotal role in CDI systems, serving as the primary approach to achieve enhanced adsorption capacity for contaminant ions and expedited ion removal rates. This study employs specifically designed organic framework structures, which are subjected to pyrolysis to facilitate the integration of cobalt nanoparticles within a carbon matrix, resulting in enhanced exposure to active sites. Revolving around its distinctive exposed structure, it exhibits exceptional electrochemical performance alongside remarkable ion removal capabilities. The adsorption capacity of anions, specifically chloride ions (500 ppm), reached 152 mg∙g−1. Additionally, the removal efficiency for low concentrations of cations such as lead ions (40 ppm) and chromium ions (20 ppm) was found to be 91.83% and 60.82%, respectively. Therefore, this study presents a novel approach for the elimination of ions from wastewater. [Display omitted] •The cobalt-carbon electrodes were prepared by pyrolysis, resulting in highly exposed surfaces that effectively enhance the adsorption of pollutant ions under an electric field.•The Co-NC material has a strong ion adsorption capacity, with an impressive capability to adsorb up to 152 mg g-1 of Cl- ions and effectively remove metal cations like Pb2+ and Cr3+.•The present study offers a rational framework for the utilization of high-performance CDI electrode materials, thereby providing a viable pathway.