Date of Final Oral Examination (Defense)
Type of Culminating Activity
Master of Science in Materials Science and Engineering
Materials Science and Engineering
David Estrada, Ph.D.
Brian Jaques, Ph.D.
Paul Simmonds, Ph.D.
Harish Subbaraman, Ph.D.
The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to scale it up for industrial applications. The efficiency of the technology depends on the architectural design of the CDI cell, control of operating conditions, and the nature of the electrodes used. In this project we report on the performance of Ti3C2Tx MXenes flow electrodes in a CDI cell design. MXenes are a novel class of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides with the general formula Mn+1XnTx where M is an early transition metal, X is carbon and/or nitrogen, Tx represents the surface terminations. Ti3C2Tx MXenes synthesized at Boise State, were employed as a flow electrode solution in an established CDI cell for targeted and selective ion removal. Performance metrics of achieved adsorption capacity, ion removal efficiency, regeneration efficiency, energy consumption, and charge efficiency, exceed those of currently prevalent electrode systems. In addition, rheological properties of the Ti3C2Tx MXenes colloidal solution were evaluated. This work establishes the deionization performance of Ti3C2Tx MXene based flow electrodes while providing further insight towards understanding the effect of structure and surface functionalization on the resultant deionization efficiency.
Mansoor, Naqsh E., "MXenes as Flow Electrodes for Capacitive Deionization of Wastewater" (2020). Boise State University Theses and Dissertations. 1726.