Potential‐Mediated Recycling of Copper From Brackish Water by an Electrochemical Copper Pump

Abstract

Copper ions (Cu 2+ ) disposed to the environment at massive scale pose severe threat to human health and waste of resource. Electrochemical deionization (EDI) which captures ions by electrical field is a promising technique for water purification. However, the removal capacity and selectivity toward Cu 2+ are unsatisfying, yet the recycling of the captured copper in EDI systems is yet to be explored. Herein, an efficient electrochemical copper pump (ECP) that can deliver Cu 2+ from dilute brackish water into much more concentrated solutions is constructed using carbon nanosheets for the first time, which works based on reversible electrosorption and electrodeposition. The trade-off between the removal capacity and reversibility is mediated by the operation voltage. The ECP exhibits a removal capacity of 702.5 mg g −1 toward Cu 2+ and a high selectivity coefficient of 64 for Cu 2+ /Na + in the presence of multiple cations; both are the highest reported to date. The energy consumption of 1.79 Wh g -1 is among the lowest for EDI of copper. More importantly, the Cu species captured can be released into a 20-fold higher concentrated solution. Such a high performance is attributed to the optimal potential distribution between the two electrodes that allows reversible electrodeposition and efficient electrosorption.

Synergistic Stabilization of Zn Metal Anodes by 3D Carbon Frameworks with Multiple Ion Channels Loaded with Zincophilic BaTiO3 Nanoparticles

“…Nanopores were also confirmed to facilitate electrolyte transport and achieve uniform ion flux, thus kinetically improving the electrochemical performance of the Zn anodes. [43,54] Additionally, the larger surface area provided by the nanopores promotes uniform local currents and lower overpotentials. [55,56] The XRD pattern proved the successful synthesis of BTO@PCNFs (Figure 1b).…”

Solar-Driven Ion Confinement for Synergetic Pollutants Remediation and Valuable Metal Recovery in Wastewater

“…In contrast to conventional PEC systems relying on Cu(II) reduction (Cu(II) → Cu(0)) for removal at a potential of 0.34 V, our designed PEC system, utilizing CuFe PBA electrode, involves an oxidation−reduction transition with Fe III (CN) 6 3+ acting as the electron acceptor. 36,37 The reduction potential for this transition was measured at 0.72 V (Fe III (CN) 6 3+ → Fe II (CN) 6 4+ ), as depicted in Figure 2e. The photocurrent results are consistent with the open-circuit voltage findings.…”

Impact of Faradaic Interlayer Confinement and Carbon‐Centered Macrostructure Designs for Ion Capture and the Recovery of Elements

“…poly(diallyldimethylammoniumchloride) (PDADMAC) and poly(sodium 4‐styrenesulfonate) (PSS) were also used as polycations and polyanion in the fabrication of layer‐by‐layer electrodes [49] . Furthermore, PPDPA poly(phenylenediamine‐co‐phthalaldehyde)‐derived carbon with nitrogen defects and meso‐ and micropores in the framework has been investigated for high selectivity of Cu + and Na + in the presence of various cations [50] . Moreover, PEDOT : PSS was included in the MXene flakes in order to give an electrochemically active site and a flexible and dense form [51] .…”

“…[49] Furthermore, PPDPA poly(phenylenediamine-co-phthalaldehyde)-derived carbon with nitrogen defects and meso-and micropores in the framework has been investigated for high selectivity of Cu + and Na + in the presence of various cations. [50] Moreover, PEDOT : PSS was included in the MXene flakes in order to give an electrochemically active site and a flexible and dense form. [51] Similarly, polyaniline (PANI) is one of the conducting polymers that has garnered a great deal of interest due to its high capacitance and low resistance, as well as its simple production process.…”