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Simulation results obtained for a solution containing 50.0 mM NaCl, a flow rate of 83 nL/min, and a current due to Cl⁻ oxidation of 2.42 μA. (a) Distribution of Cl2 near the anode. (b) Plot of the simulated concentration of solution species and pH near the anode during electrochemical Cl⁻ oxidation. The data shown correspond to z=11.50 μm (the midpoint of the channel). (c) Plot of the simulated solution conductivity as a function of axial channel position for different z heights. All simulations were performed at steady state with a 2D model based on the xz‐plane of the microfluidic system shown in Figure 1a. The black rectangle at the bottom of each plot indicates the axial position of the anode. Axial position 0 corresponds to the center of the anode, while negative and positive axial positions are upstream and downstream from the anode, respectively.
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We recently reported that electrochemical oxidation of Cl ‐ to neutral Cl 2 decreases solution conductivity, thereby yielding a local electric field gradient. Here, we report detailed experimental results and simulations indicating that the situation is more complex than we originally thought. The key new findings are twofold. First, once generated...
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... Second, the large potential applied to the IDZ-forming electrode may result in undesirable electrogenerated products that counteract IDZ formation. [47] These shortcomings motivated us to explore other electrochemical methods for forming IDZs. ...
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... To ensure that there was no pressure-driven ow (PDF) in the absence of a driving voltage, the motion of the plastic microbeads was monitored. 33 Second, a driving voltage was applied across the channel length using a power supply (PWS 4721, Tektronix, Beaverton, OR) connected to Pt electrodes located on the oor of each reservoir. Third, a BPE of the desired length was formed by connecting two Pt microbands by an external jumper wire. ...
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Electrochemical deionization technologies allow generation of potable water from contaminated sources and extraction of valuable resources from seawater, brines and industrial wastewater—all in an environmentally friendly and energy efficient manner. In this review, we detail existing electrode materials, cell architectures, and charge transfer mechanisms related to electrochemically driven desalination and selective element extraction in aqueous environments. More specifically, we address capacitive and faradaic charge-transfer processes—ion electrosorption and ion intercalation, respectively. We also address selective electrosorption/electrodeposition at functionalized electrode surfaces. The selectivity is driven by ion specific interactions at the electrode, such as chelation and redox activity. Electrochemically mediated deionization strategies can help address the global need for potable water. Their widespread adoption hinges on a thorough understanding of the range of available deionization methods—which we attempt to provide in this review.
