Nanopatterned metal–organic framework electrodes with improved capacitive deionization properties for highly efficient water desalination

Abstract

Metal–organic frameworks (MOFs) are a family of highly porous materials with great potential to replace the dominance of porous carbon materials for capacitive deionization (CDI) application. However, MOF particles cannot be directly applied to fabricate CDI electrodes without the support of polymeric binders, which would consequently lead to the formation of a pyknotic electrode structure with poorer electrical conductivity, and lower accessible surface area, limiting their further CDI application. Herein we report the preparation of free-standing MOF electrodes by patterning MOFs nanocrystals directly on carbon cloth scaffold. Through such binder-free preparation procedure, the nanopatterned MOF electrode showcases an improved electrical conductivity and accessible surface area, giving rise to a maximum desalination capacity of 21.3 mg g−1, which is higher than those of the reported MOF electrodes and many carbon-based electrodes. This work highlights the significance of binder-dree preparation procedure on the CDI performance of MOF-based electrodes, and holds great potential for practical CDI application.