Enhanced capacitive desalination of MnO2 by forming composite with multi-walled carbon nanotubes†
Abstract
The morphology and structure of the prepared MnO2/MWCNTs (multi-walled carbon nanotubes) composite are characterized by XRD, SEM, TEM, and N2 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.