REACT Lab at UNIST

Overview

We face unprecedented challenges in the 21st century, including population growth and climate change, which put great strain on our planet. Decarbonizing urban and environmental processes could reduce global carbon emission, and electrification could be a step toward carbon-neutrality in urban activities, including environmental remediation, resource recovery, and commodity chemical manufacturing. At the same time, a growing awareness of reclaiming useful components from what had previously been viewed as useless waste has encouraged researchers to come up with various revalorization strategies that can create a circular economy. By replacing fossil fuels with green and renewable energy, we intend to investigate ways to electrify separations and conversions for urbanization and environmental processes.

My research group aims to design materials from molecular level and establish electrochemical engineering principles for delicate process-level design, contributing to address challenges in environment, resource recovery from liquid- and gas-phase waste streams, nitrogen/sulfur cycling, water remediation, and energy storage, all enabled by electrified reaction and separation. Below are specific research projects.

1. Electrochemical water treatment

We will develop affordable and robust purification technologies based on electrochemical separations and degradation processes for pollutant remediation. Our research aims to mitigate the difficulty of separating highly toxic, ultra-dilute contaminants when competing species are involved. Molecular/interfacial engineering will be combined with electrochemical engineering design at a system level in the future for environmental applications, expanding the electrode materials and micropollutant domain. To characterize the effectiveness of micropollutant capture/release and conversion at practical water treatment scales, it is necessary to investigate the robustness and stability of heterogeneous interfaces. A new electrode morphology and fabrication pathway that promotes hydraulic, ionic, and electronic conduction and is resistant to degradation will allow novel materials to be implemented into practical devices for testing real samples.

Advanced Functional Materials 2020, 30 (52), 2004635.

2. Electrochemically-mediated reactive separations of nitrogen

Anthropogenically-driven disturbance in the nitrogen cycle has been a global engineering challenge. Reactive nitrogen species in waterborne and airborne waste streams can be captured and utilized as valuable substances. Aiming at resource recovery from the nitrogenous streams, ranging from wastewater to exhaust gas, we design novel electrochemical interfaces for separation and catalysis, employ understanding of electrochemical reaction pathways, and finally leverage electrochemical engineering to develop advanced nitrogen treatment technologies.

3. Recovery of critical elements in hydrometallurgical processes

The rapid growth in the market for electronic devices translates into increasing numbers of waste electric and electronic equipment (WEEE). For example, more than 10 million metric tons of lithium-ion batteries are expected to reach the end of their life between 2019-2030, and the current electric vehicle sales are estimated to be equivalent to 250,000 tons of resultant wastes battery packs. At the same time, the potentially hazardous spent batteries have been thought to be valuable resources with high metal content for secondary urban mining. However, the recovery of valuable critical elements is challenging because valuable species are leached out as minority components in the presence of excess competing species during mining. Thus, selectivity of target critical ions from either primary mining processing or from secondary waste is a key challenge in separations science. Our research will employ electrodeposition as a key strategy for metal recovery, with advantageous features of controllability, ease of operation, and selectivity, the use of electron as clean reagent, and less waste generation.