Wettability and its influence on graphene nansoheets as electrode material for capacitive deionization

• Published in: Chemical physics letters 2012-10, Vol.548, p.23-28
• Main Authors: Jia, Baoping, Zou, Linda
• Format: Article
• Language: English
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2012.06.016

Wetting behavior of graphene nanosheets and their application in capacitive deionization were discussed in this research. By altering the hydrophilicity of graphene nanosheets (GNS) through controlled introduction of sulphonic groups, the water contact angle of GNS is greatly reduced, indicating an improved wettability. Meanwhile, the sulphonated GNS showed better dispersion and higher specific surface area, probably due to the negatively charged –SO3- acting as a repellent on the surface to prevent serious aggregation. As a result, a salt removal efficiency of 83.4% and specific electrosorptive capacity of 8.6mg/g were achieved, indicating an increase of 109% in performance comparing with the unmodified GNS. [Display omitted] ► Novel reduction process attaches sulphonic groups to graphene nanosheets. ► Sulphonated graphene nanosheets as electrode material for capacitive deionization. ► Light sulphonation improves the wettability of graphene nanosheets. ► The better wettability improves electrode’s electrosorptive capacity. Wetting behavior on graphene nanosheets and their application in capacitive deionization were discussed in this research. By altering the hydrophilicity of graphene nanosheets (GNS) through controlled introduction of sulphonic groups, the water contact angle of GNS is much reduced, indicating a better wettability. Meanwhile, the sulphonated GNS showed better dispersion and higher specific surface area, probably due to the negatively charged –SO3- acting as a repellent on the surface to prevent serious aggregation. As a result, a salt removal efficiency of 83.4% and specific electrosorptive capacity of 8.6mg/g, indicating an increase of 109% comparing with the unmodified GNS.