Redox Properties of Structural Fe in Clay Minerals: 4. Reinterpreting Redox Curves by Accounting for Electron Transfer and Structural Rearrangement Kinetics.

Iron-bearing smectite clay minerals can act as electron sources and sinks in the environment. Previous studies using mediated electrochemical analyses to determine the reduction potential () values of smectites observed that the relationship between the structural Fe/Fe ratio in the smectite and varied based on the redox history of the smectite. We hypothesize that this behavior, referred to as redox hysteresis, results from the smectite particles not equilibrating with the applied over the course of the experiment (∼30 min).

Metal-Ion Depletion Impacts the Stability and Performance of Battery Electrode Deionization over Multiple Cycles.

Prussian blue hexacyanoferrate (HCF) materials, such as copper hexacyanoferrate (CuHCF) and nickel hexacyanoferrate (NiHCF), can produce higher salt removal capacities than purely capacitive materials when used as electrode materials during electrochemical water deionization due to cation intercalation into the HCF structure. One factor limiting the application of HCF materials is their decay in deionization performance over multiple cycles. By examining the performance of CuHCF and NiHCF electrodes at three different pH values (2.

Improving the Thermodynamic Energy Efficiency of Battery Electrode Deionization Using Flow-Through Electrodes.

Ion intercalation electrodes are being investigated for use in mixed capacitive deionization (CDI) and battery electrode deionization (BDI) systems because they can achieve selective ion removal and low energy deionization. To improve the thermodynamic energy efficiency (TEE) of these systems, flow-through electrodes were developed by coating porous carbon felt electrodes with a copper hexacyanoferrate composite mixture. The TEE for ion separation using flow-through electrodes was compared to a system using flow-by electrodes with the same materials.

Electrochemical Desalination Using Intercalating Electrode Materials: A Comparison of Energy Demands.

One approach for desalinating brackish water is to use electrode materials that electrochemically remove salt ions from water. Recent studies found that sodium-intercalating electrode materials (i.e.