Fabrication of cathode electrodes based on activated carbon, reduced-graphene for hybrid capacitive deionization technology

Recently, hybrid capacitive deionization (HCDI) has been a promising desalination technology because of its low cost and effective ion removal ability. The electrode material is an important factor to affect to desalination capacity of HCDI technology. In this study, the nanocomposite electrodes were fabricated successfully based on activated carbon and reduced-graphene oxide/cobalt oxide (rGO-Co3O4) and polymeric binders which were used as cathode electrodes for Hybrid capacitive deionization (HCDI) technology. The effect of polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) polymeric binders and the amount of rGO-Co3O4 on characteristic as well as specific capacitance of the nanocomposite electrodes were investigated. The nanocomposite electrode combined hydrophilic binder of PVA-based and 50 % rGO-Co3O4 has a specific capacitance of 15.3 mg/g in 200 ppm NaCl solution after 25 min at 1.2 V, which is 1.67 times higher than that of the AC-based electrode.