Cocoon derived nitrogen enriched activated carbon fiber networks for capacitive deionization

Capacitive deionization (CDI) has been attracted great interest as an emerging desalination technology and the electrode materials play a critical role on improving CDI performance. In this work, nitrogen-enriched activated carbon fibers (AN-CFs) were prepared from the natural based silk cocoon through simple carbonization and CO2 activation. Their electrochemical and electrosorption behaviors were studied in NaCl solution. The results show that AN-CFs exhibit a fibri form porous structure with rich nitrogen element and CO2 activation enhances their specific surface area. Compared with unactivated nitrogen-enriched carbon fibers (196.05 F g− 1 at 1 mV s− 1, 12.02 mg g− 1 in 1000 mg l− 1 NaCl solution), AN-CFs exhibit more excellent capacitive (236.03 F g− 1) and CDI (16.56 mg g− 1) performances, showing that CO2 activation is proved to be an effective method to improve electrochemical and electrosorption performances and the AN-CFs should be a promising electrode material for CDI application.