Facile treatment of wastewater produced in Hummer's method to prepare Mn3O4 nanoparticles and study their electrochemical performance in an asymmetric supercapacitor

Abstract

Hummer's method is one of most frequently used methods to prepare graphite oxide (GO), an intermediate of graphene nanosheets. The treatment of wastewater containing a large amount of Mn ion and acid produced in this method is very important to protect the environment and use resources efficiently. In this report, facile treatment of wastewater produced in Hummer's method was proposed to remove strong acid and transform Mn ion into Mn3O4 nanoparticles. The as-prepared Mn3O4 nanoparticles have been characterized with X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrum (FTIR). Their electrochemical performance as cathode material in an asymmetric supercapacitor was also investigated. The primary electrochemical experiment has shown that as-prepared Mn3O4 exhibited good electrochemical performance.