Water | SUSWEB

Water is life - Natures building block

Every human being needs water to survive. But still thousands of children will die this year of preventable water-related diseases. Water is becoming scarcer in areas affected by drought or conflict and as populations grow. By 2050, at least one in four people will likely live in a country affected by chronic or recurring fresh-water shortages. The challenge remains to help everyone get access to life-giving water. One of the United Nations’ new Sustainable Development Goals aims to provide universal access to clean water and sanitation by 2030. This also includes reducing pollution and improving water quality, providing adequate sanitation and hygiene access, and protecting and restoring water-related ecosystems.

Here our goal is to find technologies to produce potable drinking water from a variety of sources including brackish water, river water and seawater. We have two approaches in the water research area: i) the development of membrane capacitive deionization (mCDI) electrodes, and ii) producing redox-active electrodes for selective electrochemical separations of a variety of salts and pollutants.

I.Membrane Capacitive Deionization (mCDI)

Key article for further reading:

M. E. Suss, S. Porada, X. Sun, P. M. Biesheuvel, J. Yoon and V. Presser. Water desalination via capacitive deionization: what is it and what can we expect from it? Energy Environ. Sci., 2015, 8, 2296.

II.Redox-electrodes for Selective Electrochemical Separations

Our goals here are to look for redox electrode materials that i) can accommodate high ion loading, ii) is selective iii) has good (water) stability, and iv) has good conduction. Classes of compounds that we investigate and that meet these challenges include the layered silicates. In nature they occur as minerals such as Cuprorivaite (Egyptian Blue), CaCuSi4O10, Han Blue, BaCuSi4O10, Gillespite BaFeSi4O10, and others.

Schematic depiction of an isolated layer of MCuSi4O10 (M = Ca, Ba) with the Cu2+ ions (blue) in a square planar complex. The coordination of the M2+ ions (yellow) is through the bond, with adjoining layers complemented to an eightfold coordination (O red, Si dark green).

Key article for further reading:

X. Su, T.A. Hatton. Redox-electrodes for Selective Electrochemical Separations. Advances in Colloid and Interface Science, 2017, 244, 6-20.

X. Su, H. Kulik, T.F. Jamison, T.A. Hatton. Anion-selective redox electrodes: electrochemically mediated separation with organometallic interfaces. Advanced Functional Materials. 2016, 26(20), 3394-3404.