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Updated: Feb 28, 2026

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
Photoelectrochemical ion concentration polarization: membraneless ion filtration based on light-driven
Eunsoo Yoon1, Collin D Davies, Tim A Hooper
1Department of Chemistry, The University of Texas at Austin, 105 E. 24th St., Stop A5300, Austin, TX 78712-1224, USA. crooks@cm.utexas.edu.
Abstract:
In this article we report a microelectrochemical system that is able to partially desalinate water. The underlying principles are similar to previous reports in which a local electric field resists passage of ions. However, in the present case, no membrane is required and, most interestingly, much of the power for desalination originates from light rather than electricity. This could greatly increase the power efficiency for desalination. The device is based on a TiO2 photoanode coupled to a Pt cathode. Illumination of the photoanode drives faradaic reactions at the cathode that lead to an ion depletion zone. The resulting local electric field limits transport of charged species. In situ conductivity and fluorescence measurements demonstrate the effectiveness of the device.
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