Moderately oxidized graphene–carbon nanotubes hybrid for high performance capacitive deionization

Abstract

Capacitive deionization (CDI) is an emerging technology offering a green and efficient route to obtain clean water. According to its basic working mechanism, the covalent bond attached three-dimensional graphene/carbon nanotubes hybrid (G–CNTs) can be considered a promising material for CDI performance. In this paper, we present a novel strategy to improve wettability through moderate oxidation treatment for G–CNTs-based CDI electrodes because the poor wettability of G–CNTs will limit electrosorption performance. The results showed that the activated G–CNTs-1 h exhibited good cycling stability performance and high electrosorption capacity of 8.45 mg g⁻¹ when the initial concentration of NaCl was 500 mg L⁻¹, more than twice that of the pristine G–CNTs (3.95 mg g⁻¹). This work may provide a new insight into the future pretreatment of graphene or carbon nanotube based CDI electrode materials.