Carbon fiber sheets coated with thin-films of SiO2 and γ-Al2O3 as electrodes in capacitive deionization: Relationship between properties of the oxide films and electrode performance

Evaluation of operational parameters for a capacitive deionization reactor employing asymmetric electrodes

“…The carbon support used in this work was chosen because of its high surface area, relatively cheap cost and availability. Thus, this material, unlike other metal-oxide coated composites described elsewhere [15][16][17][18], has a surface area over 1200 m 2 g À1 . Finally, most of the work in CDI has focused on desalination/brackish water treatment [22,23], making NaCl solutions the most studied systems [7][8][9]14,21,24,25].…”

“…Other benefits such as an increase in surface area and wettability have also been observed [16], all leading to improved electrosorption capacity. However, studies in these asymmetric oxide-coated electrodes have been limited to small-scale batch experiments [15,17,18]. Therefore, performance issues associated with operating a CDI system furnished with these electrodes, handling larger processing volumes, need to be understood in order to asses the commercial feasibility of this technology.…”

“…This study was based on an asymmetric CDI configuration [2,[15][16][17][18], where the positive and negative electrodes in the system are not the same. The negative electrode is often optimized for cation electrosorption and/or anion rejection, whereas the positive electrode would be improved for anion sorption and/or cation rejection [2,19].…”

Asymmetric capacitive deionization utilizing nitric acid treated activated carbon fiber as the cathode

“…Moreover, it has been reported that some metallic oxides like aluminum oxide [42,43], silica [44] and zinc oxide [45] can also modify the Epzc of electrodes and improve CDI performance.…”

Capacitive deionization with asymmetric electrodes: Electrode capacitance vs electrode surface area

“…These imbalances have been used to selectively remove ions from solution [21,[28][29][30], but could adversely affect the equilibrium salt adsorption capacity of a CDI cell. A recent study reported that the effect of asymmetry in anode and cathode geometric ratios (where anode was 2x and 3x times larger than the cathode and vice-versa) led to an increased salt adsorption capacity, which was stated to be dependent on ionic sizes and governed by the requirement to maintain charge neutrality in solution.…”