Enhanced capacitive deionization performance of activated carbon derived from coconut shell electrodes with low content carbon nanotubes?graphene synergistic hybrid additive

With increasing desalination demand worldwide, electrode materials for capacitive deionization (CDI) have attracted extensive attention recently. To compete with Reverse Osmosis, the performance of CDI electrode still needs to be further enhanced. In this work, graphene (Gr)/carbon nanotubes (CNTs) conducting hybrid was dispersed at as low as 1 wt% in coconut shell derived activated carbon (AC) to fabricate cost effective and high performance electrode for brackish water CDI desalination. The fabricated AC/Gr/CNTs electrodes show an excellent performance with the capacitance of 60 F/g (at 5 mV/s), the salt adsorption capacity of 9.58 mg/g and salt adsorption rate of 1.51 mg/g min at 1.0 V in 200 ppm NaCl solution. It should be highlighted that owing to the synergistic effect, the role of hybrid additive (1 wt%) was demonstrated to be more effective than that of single one, from a technical as well as from an economical viewpoint. To our best knowledge, this is the first study reporting the application of ultra-low content AC/CNTs hybrid in AC based CDI electrodes. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, a cost-effective and high-performance electrode for brackish water capacitive deionization (CDI) desalination was developed by dispersing graphene/carbon nanotubes conducting hybrid in coconut shell derived activated carbon. The hybrid additive at 1 wt% showed more effective performance than single additives, demonstrating synergistic effects both technically and economically. This is the first study to report the application of ultra-low content AC/CNTs hybrid in AC based CDI electrodes.