Achieving Enhanced Capacitive Deionization by Interfacial Coupling in PEDOT Reinforced Cobalt Hexacyanoferrate Nanoflake Arrays

• Published in: Global challenges 2021-08, Vol.5 (8), p.2000128-n/a
• Main Authors: Shi, Wenhui, Xue, Meiting, Qian, Xin, Xu, Xilian, Gao, Xinlong, Zheng, Dong, Liu, Wenxian, Wu, Fangfang, Gao, Congjie, Shen, Jiangnan, Cao, Xiehong
• Format: Article
• Language: English
• Subjects: capacitive deionization; Carbon; Cobalt; Coupling; Deionization; Desalination; Durability; Electrode materials; Electrodes; Energy consumption; faradaic electrodes; Fourier transforms; Freshwater resources; Graphene; Intercalation; metal‐organic frameworks; Nanocrystals; Nanoparticles; Pigments; Prussian blue; Scanning electron microscopy; Spectrum analysis; Structural stability; water desalination; Water treatment
• ISSN: 2056-6646; 2056-6646
• DOI: 10.1002/gch2.202000128

Capacitive deionization (CDI) as a novel energy and cost‐efficient water treatment technology has attracted increasing attention. The recent development of various faradaic electrode materials has greatly enhanced the performance of CDI as compared with traditional carbon electrodes. Prussian blue (PB) has emerged as a promising CDI electrode material due to its open framework for the rapid intercalation/de‐intercalation of sodium ions. However, the desalination efficiency, and durability of previously reported PB‐based materials are still unsatisfactory. Herein, a self‐template strategy is employed to prepare a Poly(3,4‐ethylenedioxythiophene) (PEDOT) reinforced cobalt hexacyanoferrate nanoflakes anchored on carbon cloth (denoted as CoHCF@PEDOT). With the high conductivity and structural stability achieved by coupling with a thin PEDOT layer, the as‐prepared CoHCF@PEDOT electrode exhibits a high capacity of 126.7 mAh g−1 at 125 mA g−1. The fabricated hybrid CDI cell delivers a high desalination capacity of 146.2 mg g−1 at 100 mA g−1, and good cycling stability. This strategy provides an efficient method for the design of high‐performance faradaic electrode materials in CDI applications. CoHCF@PEDOT nanoflakes anchored on carbon cloth are prepared using a simple self‐template strategy. Combined with the flexibility of the carbon substrate and the high conductivity of Poly(3,4‐ethylenedioxythiophene) (PEDOT), the obtained CoHCF@PEDOT electrode has excellent desalination ability and good cycling stability. This strategy explores a new technique for synthesizing faradaic materials for capacitive deionization applications.