Multilayer graphene coated vanadium(V) oxide as electrodes for intercalation based brackish water desalination

Abstract

Present work explores graphene-coated vanadium pentoxide (G-V2O5) as novel electrosorption material for the desalination of low molarity saline/brackish water. During the desalination cycles, along with the electrical double layer formation at the graphene layer, ion intercalation is observed in the honeycomb structure of the hydrothermally grown V(2)O(5)layer leading to an improvement in Na(+)and Cl(-)ion removal from the brackish water. The conventional capacitance tests by pairing G-V(2)O(5)electrodes in a three-electrode cell shows a remarkable capacitance value of 500 F g(-1), and the capacitive deionization process over 50 cycles at 5, 10 and 15 mM concentration (NaCl) gives a maximum salt adsorption capacity of 12.5 mg of NaCl per gram of electrode. Utilizing the faradaic and non-faradaic process for electrosorption desalination paves a way towards exploring alternative materials and their hybrids for water purification applications.