Investigation of the Pharmacologic Role of Nitric Oxide
via an Electrochemical Platform

 Studies on the reactions of biological molecules in cells are crucial to reveal the molecular mechanisms behind biological processes. Nitric oxide (NO) is a significant gaseous signaling molecule with diverse physiological roles, including neuronal signal transmission and maintaining biological system homeostasis. Interestingly, the role of NO has been debated, as it can have both anti-tumor and pro-tumor effects depending on its concentration. The diffusive nature of NO and its rapid decaying have posed challenges in studying its role. In this study, we developed an electrochemical platform to regulate NO gas supply to cells and explore its effects on tumor cells.

  Our study aims to systematically investigate the role of NO through spatiotemporal regulation. The platform employs metal oxide nanocatalysts, with iron oxide (Fe3O4) nanoparticles exhibiting selective NO generation under low overpotentials. Using our spatio-temporal electrochemical platform ESCoRT(Electrochemical System for Conveyance of Radicals to Tumor cell), we systematically investigated the role of NO by studying cellular responses in A549 tumor cell lines under specific electrochemical conditions. Notably, we observed distinct trends in cell viability depending on the applied voltage, distance, and exposure time from the electrode. Parameters such as effective distance range, chronoamperometry duration, and NO yield rate were found to be critical factors influencing cell death. This standardized electrochemical device provides valuable insights into the reactivity of cells to external radical gases, enhancing our understanding of the biological response to gas molecules in both intra- and extra-cellular microenvironments.

Performance of single metal nitride nanoparticles for oxygen evolution reaction

For a long time, we have obtained energy through fossil fuels, however, environmental problems have become a serious concern. As a result, people are searching for eco-friendly energy substitutes. Hydrogen energy is a fascinating and eco-friendly energy source that can replace fossil fuels and can be easily obtained through oxygen evolution reaction (OER). Our group aims to use metal nitrides as catalysts in the OER. When metal nitrides are formed, nitrogen atoms occupy interstitial sites, causing changes in the d-band. As the d-band shifts towards the Fermi level, the unoccupied density of states (DOS) in the d-band increases. Consequently, the occupied DOS in the d-band decreases, resulting in a narrowing of the d-band. This leads to the near-Fermi level d-band states remaining unoccupied, causing a significant reduction in electron transfer at the surface. Paradoxically, this phenomenon enhances the catalytic properties by making the catalyst more effective at accepting electrons, thereby significantly improving conductivity. Therefore, metal nitride catalysts have good conductivity, high stability, and high corrosion resistance in OER. Our group intends to develop a high-activity and stability catalyst using metal nitride nanoparticles.
In this study, we aim to investigate the activity of nitride nanoparticles for each metal in the context of the OER. Our goal is to identify the most efficient nanoparticle among them. While the activity of the single metal nitride nanoparticle catalyst may not exceed that reported in previous literature, we intend to enhance efficiency by introducing heterogeneous catalysts into the system.

Spin-state control of electrochemical catalyst
for selective Oxygen-Atom transfer and Hydrogen Abstraction

In the modern chemical industry, epoxides have been regarded as pivotal ingredients for chemical synthesis. In general, the reactive three-membered heterocyclic ring in epoxides can be opened by nucleophilic groups, thus easily introducing diverse functionality. Currently, thermochemical routes are employed to epoxide target olefins under elevated temperature and high pressure. Given that the whole country aims to build a carbon-neutral society, it would be essential to exploit sustainable methodologies to replace the current route.

Herein, we report electrocatalytic epoxidation via the generation of Co-oxo intermediate in Co-TAML(tetraamido macrocyclic ligand) molecular catalysts. 

Selective amine preparation pathways
using electrochemical reductive amination

The selective construction of carbon-nitrogen bonds has been considered as one of the central tasks of chemical synthesis, as they are basic structural units that constitute various natural products, pharmaceuticals, and bioactive molecules. For instance, amine functional groups can be found in methyl orange (pH indicator), chlorpheniramine (antihistamine), and adrenaline (hormone). A commonly employed method to prepare amines is reductive amination, which exhibits high chemo-selectivity and is cost-effective.

In this study, we demonstrated a new strategy to catalyze the reductive amination process. Moreover, we suggested selective pathways for the preparation of various amines using electrochemistry.

Sustainable Electrochemical Olefin Epoxidation
using Metal-Porphyrin Catalysts

Epoxidation is widely recognized oxidation reaction of significant importance in both academic research and industrial applications.
Even though epoxides have been mainly produced thermochemically with various catalysts and oxidants such as peroxides and peracids, due to the harsh conditions and for carbon neutrality, epoxidation by sustainable and greener electrochemical method is necessary
In this study, we established a sustainable pathway for electrochemical olefin epoxidation by metal porphyrin catalysts