Ultrahigh Performance of Novel Energy-efficient Capacitive Deionization Electrodes based on 3D Nanotubular Composites

N. Allam
The American University in Cairo,

Keywords: capacitive deionization, desalination efficiency, conductivity, salt rejection, electrodes


Capacitive deionization (CDI) is being progressed as an auspicious ions removal technique from brackish and seawater. Herein, we introduce a novel one-step facile chemical approach to fabricate tubular architectured composite electrodes made of both Titania and Multi-walled carbon nanotubes (TNTs/MWCNTs). The composites have been exploited, for the first time, as the electrode materials for capacitive deionization. The composite electrodes were fully characterized via Field Emission Scanning Electron Microscopy (FESEM), Raman spectroscopy, X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) techniques, and Nitrogen Sorption. The electrochemical response was investigated by using Cyclic Voltammetry (CV), Galvanostatic Charge and Discharge (GCD), and Potentio-Electrochemical Impedance Spectroscopy (PEIS) measurements. The fabricated composite electrodes containing 5 wt% TiO2 nanotubes showed a remarkable specific capacitance, conductivity, reversibility, and durability compared to pristine MWCNTs and other MWCNTs-based composite electrodes reported in the literature. The desalination capability of the composite electrode was investigated using batch mode operation. The electrosorption capacity of the composite electrode containing 5 wt% TiO2 nanotubes (13.2 mg/g) is approximately two folds of magnitude larger than that of pristine MWCNTs (7.7 mg/g), indicating an improved desalination efficiency. Therefore, the fabricated TNTs/MWCNTs composite electrode is a promising candidate for CDI technology.