Enhanced capacitive desalination of MnO2 by forming composite with multi-walled carbon nanotubes

The morphology and structure of the prepared MnO2/MWCNTs (multi-walled carbon nanotubes) composite are characterized by XRD, SEM, TEM, and N-2 sorption analysis. The electrochemical performance of the composite is studied by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge evaluation. The composite has a specific capacitance of 144 F g(-1) at the current density of 1 A g(-1). It has higher conductivity which is affirmed by electrochemical impedance spectroscopy (EIS). The capacitive deionization (CDI) test was conducted in a bath mode apparatus by assembling a capacitor. The capacitor made from MnO2/MWCNTs composite shows a higher desalination capacity of (6.65 mg g(-1)) in NaCl aqueous solution, higher than that made from the virginal MnO2 (1.60 mg g(-1)) and those of the formerly reported. Furthermore, the MnO2/MWCNTs composite electrode shows excellent recyclability with an efficient and rapid regeneration process.