(713a) Advanced Redox-Polymer Interfaces for Water Purifications: Electrochemical Reactive Separations

Advanced redox-functionalized electrodes offers a powerful platform for performing selective electrochemical separations.^1-3 In our work, we discuss the development of new redox-active electrodes for selective separation performance of heavy metal pollutants, as well as the integration of reactions and separations to enable process intensification for water purification and environmental remediation. First, the tandem selective capture and conversion of As(III) to As(V) is achieved using an asymmetric design of metallopolymer and radical-based polymer,⁴ which, during adsorption, allows selective separation of As(III) by metalloplymer in the presence of excess of competing ions, and during release, enables synergistic electrocatalytic oxidation of As(III) to As(V) with >90% efficiency by radical-based polymer. The judicious design of asymmetric redox-active interfaces demonstrates >90% removal efficiency with real wastewater, final concentrations of arsenic as low as 10 ppb, and an order-of-magnitude energy efficiency increase compared to non-faradaic, carbon-based systems. Second, the capabilities of redox-electrodes are leveraged towards reactive separations of emerging organic contaminants of concern. We discuss the integrated capture and degradation of a number of complex organic contaminants, enabled by the judicious design of electrode materials and electrochemical engineering parameters. Our results are expected to provide an energy-efficient platform for sustainable separations and environmental remediation.

References:

1. X. Su, K.J. Tan, J. Elbert, C. Ruttiger, M. Gallei, T.F. Jamison, T.A. Hatton. Asymmetric Faradaic systems for selective electrochemical separations. Energy & Environmental Science, 2017, 10, 1272-1283.
2. X. Su, T.A. Hatton. Redox-electrodes for selective electrochemical separations, State-of-Art Perspective. Advances in Colloid and Interface Science, 2017, 244, 6-20.
3. X. Su, T. A. Hatton. Electrosorption at functional interfaces: from molecular-level interactions to electrochemical cell design. Physical Chemistry Chemical Physics, 2017, 19, 23570-23584.
4. K. Kim, S. Cotty, J. Elbert, R. Chen, C.H. Hou, X. Su. Asymmetric Redox-Polymer Interfaces for Electrochemical Reactive Separations: Synergistic Capture and Conversion of Arsenic. Advanced Materials, 2020, 32(6), 1906877.