Effect of a semiconductor dielectric coating on the salt adsorption capacity of a porous electrode in a capacitive deionization cell

Karthik Laxman, Myo Tay Zar Myint, Rashid Khan, Tasneem Pervez, Joydeep Dutta

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

A theoretical model was developed to study the effect of an additional dielectric coating on the conducting electrodes in a capacitive deionization cell. The electric field generated at the electrode surface and its distribution was quantitatively investigated for coating materials with different dielectric properties. The model shows that a nanostructured low dielectric and intrinsically polar material like zinc oxide (ZnO) is well suited to enhance the efficiency of capacitive desalination. Electrodes formed by ZnO nanorods coated on conducting electrodes of activated carbon cloth (ACC) were subsequently fabricated and its desalination parameters were studied using a 17 mM (1000 ppm) NaCl solution as the feed at an applied potential of 1.6 V DC. The composite ZnO nanorod coated electrodes improved salt removal efficiency by 40%, and adsorbed 35% of the salt in a single pass experiment, at a charge efficiency of 80% and an electrosorptive capacity of 8.1 mg/g of the electrode. A simultaneous increase in the ion adsorption rate led to a ∼40% reduction in the energy consumption as compared to an uncoated ACC electrode.

Original languageEnglish
Pages (from-to)329-337
Number of pages9
JournalElectrochimica Acta
Volume166
DOIs
Publication statusPublished - Jun 1 2015

Fingerprint

Salts
Semiconductor materials
Adsorption
Coatings
Electrodes
Zinc Oxide
Zinc oxide
Desalination
Nanorods
Activated carbon
Salt removal
Dielectric properties
Energy utilization
Electric fields
Ions
Composite materials
Experiments

Keywords

  • Activated carbon cloth
  • Capacitive deionization
  • Dielectric layer
  • Electric field
  • Zinc oxide

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

Cite this

Effect of a semiconductor dielectric coating on the salt adsorption capacity of a porous electrode in a capacitive deionization cell. / Laxman, Karthik; Myint, Myo Tay Zar; Khan, Rashid; Pervez, Tasneem; Dutta, Joydeep.

In: Electrochimica Acta, Vol. 166, 01.06.2015, p. 329-337.

Research output: Contribution to journalArticle

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