Capacitive deionization of salt water using (Cu-Ag)@C electrodes

W.-T. Chang, J. Wang, Y.-J. Tuan, H.P. Wang
National Cheng Kung University,
Taiwan

Keywords: capacitive deionization, disinfection, desalination, salt water

Summary:

Fresh water shortage is becoming a worldwide problem. Thus, the main objective of this work was to prepare new nanostructured electrodes for capacitive deionization (CDI) of salt water with an additional function of disinfection. To prepare (Cu-Ag)@C core-shell nanoparticles for the CDI electrodes, Ag+- and Cu2+-β-cyclodextrin complexes were carbonized at 673 K. The nano Cu-Ag bimetals with an average crystalline size of 10 nm are encapsulated in carbon-shell. The nature carbon materials have been the key for a better CDI performance. The (Cu-Ag)@C nanoparticles dispersed on graphene (rGO) were used for deionization and disinfection of salt water. The average CDI efficiency of the (Cu-Ag)@C/rGO electrodes in the four cycles is 35% approximately. Additionally, the disinfection efficiency is as high as 90% during CDI. Apparently the (Cu-Ag)@C/rGO electrodes can be used for salt water desalination with a very high disinfection ability for recycling water.