Kwiyong Kim

Abstract Molecularly-selective metal separations are key to sustainable recycling of Li-ion battery electrodes. However, metals with close reduction potentials present a fundamental challenge for selective electrodeposition, especially for critical elements such as cobalt and nickel. Here, we demonstrate the synergistic combination of electrolyte control and interfacial design to achieve molecular selectivity for cobalt and nickel during potential-dependent electrodeposition. Concentrated chlori

Abstract Nitrate is a ubiquitous aqueous pollutant from agricultural and industrial activities. At the same time, conversion of nitrate to ammonia provides an attractive solution for the coupled environmental and energy challenge underlying the nitrogen cycle, by valorizing a pollutant to a carbon-free energy carrier and essential chemical feedstock. Mass transport limitations are a key obstacle to the efficient conversion of nitrate to ammonia from water streams, due to the dilute concentration

Advanced redox-polymer materials offer a powerful platform for integrating electroseparations and electrocatalysis, especially for water purification and environmental remediation applications. The selective capture and remediation of trivalent arsenic (As(III)) is a central challenge for water purification due to its high toxicity and difficulty to remove at ultra-dilute concentrations. Current methods present low ion selectivity, and require multistep processes to transform arsenic to the less

Selection of an appropriate electrolyte medium is essential for successful NH3 electro-synthesis at low temperature and pressure. In this study, 2-propanol was employed as an electrolyte medium and its effectiveness in the electro-reduction of N-2 to NH3 under ambient conditions was evaluated. NH3 synthesis and faradaic efficiency using a mixture of 2-propanol/water (9:1, v/v) surpassed those when electrosynthesis was carried out using solely water. The concentration of H2SO4 and the applied cur

Critical minerals are essential for the ever-increasing urban and industrial activities in modern society. The shift to cost-efficient and ecofriendly urban mining can be an avenue to replace the traditional linear flow of virgin-mined materials. Electrochemical separation technologies provide a sustainable approach to metal recovery, through possible integration with renewable energy, the minimization of external chemical input, as well as reducing secondary pollution. In this review, recent ad

In this study, a novel electrolysis cell based on ethylenediamine (EDA) as a cathodic solvent was developed for NH3 electro-synthesis. The NH3-generating cathode chamber was filled with 0.1 M LiCl/EDA and separated by a cation exchange membrane from the anodic compartment, which was filled with 0.05 M H2SO4 aqueous solution. It appeared that EDA was cathodically stable, and thus electron-stealing medium destruction was substantially avoided. The faradaic efficiency for NH3 synthesis was 17.2%, p

Lithium-mediated reduction of dinitrogen is a promising method to evade electron-stealing hydrogen evolution, a critical challenge which limits faradaic efficiency (FE) and thus hinders the success of traditional protic-solvent-based ammonia electro-synthesis. A viable implementation of the lithium-mediated pathway using lithium-ion conducting glass ceramics involves i) lithium deposition, ii) nitridation, and iii) ammonia formation. Ammonia was successfully synthesized from molecular nitrogen a

Abstract Molecular design of redox‐materials provides a promising technique for tuning physicochemical properties which are critical for selective separations and environmental remediation. Here, the structural tuning of redox‐copolymers, 4‐methacryloyloxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TMA) and 4‐methacryloyloxy‐2,2,6,6‐tetramethylpiperidine (TMPMA), denoted as P(TMA x ‐ co ‐TMPMA 1− x ), is investigated for the selective separation of anion contaminants ranging from perfluorinated substa

A membrane-free electrochemical cell provides a green and economic way of lithium deposition and its utilization for lithium-mediated ammonia synthesis.

Electro-reduction of nitrogen aided by lithium offers a new route for ammonia synthesis. In this novel approach, the first step of lithium plating plays a determining role in faradaic efficiency (FE) of the electro-synthesis process. It was found that the simple addition of cesium salt in a conventional organic electrolyte enhanced Li plating performance (FE of 82.3% for ammonia synthesis) to a substantial extent. This improvement appeared to have a lot to do with a Cs-caused change in morpholog