Ag-Cu bimetallic nanoparticle decorated graphene nanocomposite as an effective anode material for hybrid capacitive deionization (HCDI) system

Muthukumaraswamy Ranagraj Vengatesan,Ismail Farouq Fahmi Darawsheh,Bharath Govindan,Emad Alhseinat,Fawzi Banat

doi:10.1016/j.electacta.2018.12.004

Muthukumaraswamy Ranagraj Vengatesan, Ismail Farouq Fahmi Darawsheh + Show 3 more

https://doi.org/10.1016/j.electacta.2018.12.004

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Abstract

An effective battery electrode material with a good capacitance and excellent conductivity is highly demanding for the hybrid capacitance deionization (HCDI) application. Bimetallic nanoparticles (NPs) decorated graphene composites have received significant attention, and it might improve the storage space and the conductivity of the electrode material. Herein, we used bimetallic silver (Ag) - copper (Cu) decorated graphene (ACG) nanocomposite as the anode electrode material for the HCDI application and studied its deionization performance. Also, the HCDI performance of the ACG has been compared with monometallic Cu-doped graphene (CG) and Ag-doped graphene (AG) nanocomposites. Both the bimetallic and monometallic nanocomposites have been generated by a facile thermal treatment method. X-ray photoelectron spectroscopy (XPS) analysis confirmed the existence of Cu and Ag nanoparticle in the graphene nanostructure with the +2 and 0 oxidation states respectively. Transmission electron microscopy (TEM) analysis displays the uniform distribution of nanoparticles with both phases of Cu and Ag on the graphene sheets and the size of around 20–60 nm. Electrochemical measurements showed that the ACG exhibits the good specific capacitance of 128 Fg−1 as compared to monometallic AG and CG composites of 118 Fg−1 and 101 Fg−1 respectively. Furthermore, the HCDI measurements reveal that the ACG nanocomposite electrode showed the salt adsorption capacity (SAC) of 16.81 mg g−1 with initial salt concentration of 600 ppm, and the applied voltage of 1.2 V. Besides, the ACG based HCDI cell possessed the charge efficiency of 90% and the energy consumption of 88 kJ mol−1 at 1.2 V. Also, the ACG nanocomposite electrode showed good stability regeneration ability over 10 charge− discharge cycles. The present study introduced the developed bimetallic graphene composite electrodes as effective electrodes for HCDI technology.

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