Modification of carbon xerogel electrodes for more efficient asymmetric capacitive deionization

Xin Gao, James Landon, James K. Neathery, Kunlei Liu

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


Since a capacitive deionization (CDI) cell is a type of electrochemical device, its performance will be limited by the electrode with a weaker ion-adsorption. A cyclic voltmmogram for a freshly prepared carbon xerogel (CX) electrode showed Na+ adsorption at the cathodic branch is not as favorable as Cl- adsorption at the anodic branch in a ∼4 mM (∼233 ppm) NaCl solution. To balance this performance, the CX electrode was specifically modified by coating with SiO2 particles and by the formation of surface -COOH groups from oxidation. It was observed that these modifications cannot only increase the cathodic current density but also adjust the location of the potential of zero charge (PZC) for the CX electrode, resulting in the enhancment of Na+ adsorption. In CDI tests, electrosorption performance showed that cells with modified negative CX electrodes had much higher electrosorption capacities, e.g., at 1.2 V, electrosorption capacity for the modified electrodes increased by 36-50% in comparison to that for the unmodified CX negative electrode. This improvement of electrosorption performance is attributed to both an increase in total charge passed through the cell and the adjustment of the PZC leading to diminished co-ion repulsion.

Original languageEnglish
Pages (from-to)E106-E112
JournalJournal of the Electrochemical Society
Issue number9
StatePublished - 2013

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry


Dive into the research topics of 'Modification of carbon xerogel electrodes for more efficient asymmetric capacitive deionization'. Together they form a unique fingerprint.

Cite this