(6kj) Illuminating Solid-Water Interfacial Processes at Nanoscale for Sustainable Environmental Remediation and Resource Recovery

My research has focused on diverse redox reactions and subsequent crystal nucleation and growth of nanoparticles occurring at solid-water interfaces in nature and engineered application systems. The overarching goal is to understand unconsidered crucial roles that abiotic and biotic sources play in redox reactions of transition metals and to develop sustainable chemistry for water treatment and energy applications. Through my Ph.D. and postdoctoral researches, I have elucidated the crucial effect of interfacial processes on the nucleation of geological (Mn oxides) and engineering materials (Li dendrite) using in situ/ex situ synchrotron-based X-ray techniques and atomic force microscopy (AFM). By applying photo- and electrochemical redox reactions, I have obtained fundamental understanding of redox reactions and (trans)formation of nanoparticles, all of which occur at solid-solution interfaces.

The diverse routes for redox reactions and nucleation have inspired me to learn more about how nature forms different mineral phases via abiotic and biotic redox reactions and subsequent nucleation, and how I can use this understanding to develop better engineered applications, sustainable chemistry, and sustainable engineering. To embody the curiosity and enthusiasm, I am interested in pursuing the following projects.

Research Interests:

With growing populations and improved standards of living in the world, we are facing daunting challenges in environmental sustainability: sustainably supplying food, water, and energy and designing a future without pollution or waste¹. Based on the ubiquitous presence and substantial surface energy (~100 J g^-1) of minerals and nanoparticles in nature and engineered systems, understanding the interfacial processes at the molecular level is significant to treat contaminants and to design sustainable systems ³. With a strong fundamental background and techniques of interfacial processes (e.g., in situ/ex situ synchrotron-based X-ray and AFM), my interdisciplinary research aims to understand local, regional, and global aspects of elemental cycles and impacts of pollution at the molecular level in natural and engineered systems. The fundamental understanding of solid-water interfaces at the molecular level will enable my research group not only to design an improved system for the mitigation of pollution and waste, but also to recover resources from waste, all of which occur at the interface between solid and water. My research will focus on the three major projects:

Project 1: Establishing a new understanding of the interfacial processes of metal oxides and emerging contaminants in nature and engineered aquatic systems.

Understanding of the physico-chemical nature of the interfacial processes still remains elusive because of extreme difficulties in analyzing such interfaces in their relevant environments (e.g., in situ), as they evolve (e.g., in real-time), and lack of knowledge at the molecular-scale resolution. This project will explain the fate of metal oxides (or nanoparticles) at mineral-water interfaces, and important roles in controlling the redox reaction and structure of natural minerals under environmentally relevant conditions. Specifically, by developing in situ characterization platform (such as synchrotron-based X-ray absorption/scattering (e.g., XAS and SAXS/WAXS) and electrochemical-AFM), my group will not only visualize how Mn oxide nanoparticles form and react with contaminants depending on redox conditions at nanoscale interface, but also elucidate a new Eh-pH diagram (Pourbaix diagram) obtained from nanoscale analyses.

Project 2: Sustainable synthesis of nanomaterials and developing re-activation system of the nanomaterials in contaminant removal and energy catalysis.

Designing a system is the most critical stage in determining the types and amounts of wastes or pollutions. While Mn(III/IV) oxides are very useful environmental and energy catalysts, due to its high reactivity and redox capacity, previous studies have shown that external heat and pressure are necessary to control the structure and oxidation state of Mn oxides. Also, the decay of reactivity occurs because of the reduction of Mn(III/IV) to Mn(II) in engineering applications systems. Using the design of green chemistry (reducing extra chemicals and external energy), we will synthesize varied structures of Mn(III/IV) oxides, and develop the re-activation mechanism of them in the energy and environmental applications.

Project 3: Mining valuable elements from waste: A low-cost green approach for Lithium-ion battery recycling.

The popularity of electric vehicles (EV) starts to grow explosively. This substitution of fossil-fueled vehicles to EV will generate multimillion-metric-tons of used Li-ion batteries. This situation recently drives researchers to recycle valuable materials in the used Li-ion batteries. However, current recycling pathways are energy-intensive or environmentally-harmful processes (e.g., high-temperature melting-and-extraction, chemical-extraction using strong acids). My research group will aim to develop sustainable pathways to dissemble cathodes, containing valuable metals (e.g., Co, Mn, Ni) using biotic processes (e.g., microbes), and selectively uptake the metals using (photo)electrochemistry. This project will bring a cost-effective and sustainable processes of Li-ion battery recycling.

Teaching Experience:

My experiences in lecture and teaching assistant for graduate and undergraduate are transport phenomena, kinetics and thermodynamics, which are my teaching interests as well, in environmental and engineered systems. In aquatic chemistry and geochemistry classes, I gave lectures for kinetics and thermodynamics in environmental systems. Also, as a teaching assistant in thermodynamic course of chemical engineering, I leaded problem-solving classes for undergraduate students biweekly. I also had experiences in laboratory courses of general chemistry lab and environmental engineering lab as a teaching assistant. Specially, I was an instructor of general chemistry lab for 2 years in my master degree. The experiences helped for me to learn how to make students motivated and teach them efficiently.

As a research mentor, I have mentored for 3 graduate students, 3 undergraduate students, and 1 high school student. In particular, I have learned how it is joyful to be a mentor for a beginner by working with one of the undergraduate students for 2 years. This experience was basically learning process for me about how advisors teach graduate students. Providing motivations for a conducting project and careful advices made her as the most outstanding undergraduate researcher in her class. She became 1^st author in a peer-reviewed journal (crystal growth & design) with me, and got research awards from ACS and Washington University in St. Louis. In this way, I have learned how to teach new subjects to students and research beginners and the importance of knowing your audience and presenting information clearly.

Teaching Interests:

Due to my background in aquatic chemistry, kinetics, and thermodynamics in environmental and chemical engineering systems, I would be particularly well-suited and interested in teaching kinetics and thermodynamics, and aquatic chemistry for both undergraduates and graduates. Also, my most favorite course, which I got an award at collegiate competition hosted by the Korean Institute of Chemical Engineers, is transport phenomena which including fluid dynamics, heat transfer, and mass transfer. I can develop the course at the view point and issues of environmental and energy systems.

Together with the development of the pre-existing courses, I will also add new curriculum of the department, environmental nanochemistry. This course involves the study of nanochemistry at various environmental interfaces, focusing on colloid, nanoparticles, and surface reactions. The aim of this course is to help students attain a better understanding of how nanoscience could potentially lead to better water treatments, more effective contaminated-site remediation, or new energy alternatives.

Successful Proposals:

Funding Proposals

Photochemically-Induced Nucleation and Growth of Manganese Oxides at Environmental Interfaces (NSF CHE-1610728), Contribution: developed first idea and results, and made a draft. ($ 402,000.00)

Selected Synchrotron National Facility Beamtime Proposals (20 proposals in total)

Haesung Jung, and Yuanzhi Tang, Effects of metal impurities on the redox property and structure of layered manganese oxides, NSLS II 6BM (National Synchrotron Light Source II, Brookhaven National Laboratory) beamtime proposal (2019-2): XAS experiments.

Young-Shin Jun, Haesung Jung, Byeongdu Lee, and Doyoon Kim, Photochemically-assisted Fast Abiotic Oxidation of Mn²⁺ (aq), and Nucleation and Growth of δ-MnO₂ at Environmental Interfaces, APS 12ID-B (Advanced Photon Source, Argonne National Lab) beamtime proposal (2017-1): In situ time-resolved GISAXS measurements.

Selected Publications:

Haesung Jung, Byeongdu Lee, Miklos Lengyel, Richard Axelbaum, Jeeyoung Yoo, Youn Sang Kim, and Young-Shin Jun, “Nanoscale in situ Detection of Nucleation and Growth of Li Electrodeposition at Various Current Densities”, Journal of Materials Chemistry A, 2018, 6, 4629–4635.

Haesung Jung, Tandeep Chadha, Yujia Min, Pratim Biswas, and Young-Shin Jun, “Photochemically-assisted Synthesis of Birnessite Nanosheets and Alteration of Its Structure in the Presence of Pyrophosphate”, ACS Sustainable Chemistry & Engineering, 2017, 5, 10624–10632.

Yue Hui^†, Haesung Jung^†, Doyoon Kim, and Young-Shin Jun, “Kinetics of α-MnOOH Nanoparticle Formation through Enzymatically-catalyzed Bio-mineralization inside Apoferritin”, Crystal Growth & Design, 2017, 17, 5675–5683. ^†The authors contributedequally.

Haesung Jung, Tandeep Chadha, Doyoon Kim, Pratim Biswas, and Young-Shin Jun, “Photochemically-assisted Fast Abiotic Oxidation of Manganese and Formation of δ–MnO₂ Nanosheets in Nitrate Solution”, Chemical Communications, 2017, 53, 4445–4448.

Haesung Jung and Young-Shin Jun, “Ionic Strength-controlled Mn (Hydr)oxide Nanoparticle Nucleation on Quartz: Effect of Aqueous Mn(OH)₂”, Environmental Science & Technology, 2016, 50, 105–113.

Selected Awards:

Graduate Student Research Award in Environmental Chemistry Division, American Chemical Society, 2018

Graduate Student Research Award in Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, 2017