Enhanced electro-adsorption desalination performance of graphene by TiC

Abstract

Capacitive deionization (CDI) process is aiming to desalinate water samples by electrosorption of salty ions on the surfaces of electrodes with opposite charges. Therefore, the choice of the electrode material has its main role in controlling the overall efficiency of synthesized CDI cell. In this work, graphene nanoflakes (GNFs) were examined as an interesting carbon-based material in CDI technology. Their electrochemical and desalination characteristics were significantly enhanced by introducing TiC nanoparticles in different wt.% values [5, 10 and 20] through the application of microwave irradiation followed by hydrothermal treatment. The morphology, crystal structure, porosity, composition and hydrophilic nature of fabricated nanomaterials were investigated using scanning and transmission electron microscopes (SEM, TEM), X-ray diffractometer (XRD), N2 adsorption – desorption isotherms, energy dispersive X-ray analyzer (EDX) and water contact angle measurements, respectively. Electrochemical studies revealed outperformed specific capacitance values of TiC incorporated graphene nanoflakes by 5.53, 14.47 and 7.64 folds for those containing 5, 10 and 20 wt% TiC, respectively when compared to the estimated one using GNFs at 5 mV s−1. An excellent salt removal efficiency value of 91% was calculated when 10 wt% TiC was added to GNFs with electrosorption capacity of 22.8 mg g−1 at conductivity value of 1 mS cm−1. Galvanostatic charge–discharge experiments revealed good reversible performance of this nanomaterial with high stability over 30 cycles. These obtained results could elect TiC incorporated GNFs as suitable candidates for water desalination using CDI technology.