A5101532810- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Electrocatalysts for Energy Conversion
- MXene and MAX Phase Materials
- Advanced battery technologies research
- 2D Materials and Applications
- X-ray Diffraction in Crystallography
- Chalcogenide Semiconductor Thin Films
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- ZnO doping and properties
- Synthesis and biological activity
- Quantum Dots Synthesis And Properties
- Synthesis and Characterization of Heterocyclic Compounds
- Graphene research and applications
- Semiconductor materials and interfaces
- Silicon Nanostructures and Photoluminescence
- Advanced X-ray Imaging Techniques
- GaN-based semiconductor devices and materials
- nanoparticles nucleation surface interactions
- Semiconductor materials and devices
- Force Microscopy Techniques and Applications
- Electronic and Structural Properties of Oxides
- Catalytic Processes in Materials Science
- Fuel Cells and Related Materials
Korea Basic Science Institute
2015-2024
Korea Polytechnic University
2021
Daejeon University
2015-2019
Government of the Republic of Korea
2017-2019
Agency for Defense Development
2014-2019
Seoul National University of Science and Technology
2016
Sungkyunkwan University
2010-2011
Konkuk University
2011
Dankook University
2010
Korea University
2007
Abstract Cobalt hydroxide is a promising electrode material for supercapacitors due to the high capacitance and long cyclability. However, energy storage/conversion mechanism of cobalt still vague at atomic level. Here we shed light on how functions as supercapacitor operando conditions. We find that specific cycling life involve complete modification morphology, which usually believed be unfavourable but in fact has little influence performance. The conversion during charge/discharge...
Development of nanostructured materials with enhanced redox reaction capabilities is important for achieving high energy and power densities in storage systems. Here, we demonstrate that the nanohybridization ionic liquids (ILs, 1-butyl-3-methylimidazolium tetrafluoroborate) cobalt hydroxide (Co(OH)2) through ionothermal synthesis leads to a rapid reversible reaction. The as-synthesized IL-Co(OH)2 has favorable, tailored morphology large surface area 400.4 m(2)/g mesopore size 4.8 nm. In...
Ternary alloying of transition metal dichalcogenides (TMDs) has the potential for altering electronic structure materials to suit electrochemical applications. Herein, we synthesized (MoWV)Se2 nanosheets at various compositions via a colloidal reaction. The mole fraction V atoms (xV) was successfully increased up 0.8, producing metallic phase that is highly durable against hydration. Furthermore, (MoW)Se2 over entire composition range. atomic mixing ternary alloys more random than...
The novel properties of two-dimensional materials have motivated extensive studies focused on transition metal dichalcogenides (TMDs), which led to many interesting findings in recent years. Further advances this area would require the development effective methods for producing nanostructured TMDs with a controlled structure. Herein, we report unique MoS2 layered nanostructures intercalated dimethyl-p-phenylenediamine (DMPD) various concentrations, synthesized by one-step hydrothermal...
Alloys of transition-metal dichalcogenide can display distinctive phase evolution because their two-dimensional structures. Herein, we report the colloidal synthesis Mo1–xVxSe2 alloy nanosheets with full composition tuning. Alloying led to a transition at x = 0.7 from semiconducting 2H MoSe2 metallic 1T VSe2. It also produced significant V and Se vacancies, which became richest in 0.3–0.5. Extensive spin-polarized density functional theory calculations consistently predicted 2H–1T 0.7,...
Polytypes of two-dimensional transition metal dichalcogenide can extend the architecture and application nanostructures. Herein, Nb1-xVxSe2 alloy nanosheets in full composition range (x) were synthesized by a colloidal reaction. At x = 0.1-0.3, phase occurred from various hexagonal (three 2H one 4H types) NbSe2 to an atomically homogeneous 1T VSe2. Density functional theory calculations also revealed polytypic at 0.3, which was shifted close 0 presence Se vacancies. Furthermore, validate...
Tuning the electronic structures of transition metal dichalcogenides (TMD) is essential for their implementation in next-generation energy technologies. In this study, we synthesized composition-tuned WSe2-VSe2 (W1-xVxSe2, x = 0-1) alloyed nanosheets using a colloidal reaction. Alloying semiconducting WSe2 with VSe2 converts material into metallic one, followed by 2H-to-1T phase at 0.7. Over wide composition range, and are atomically immiscible form separate ordered domains. The miscible...
The dissolution of transition metal ions causes the notorious peeling active substances and attenuates electrochemical capacity. Frustrated by ceaseless task pushing a boulder up mountain, Sisyphus Greek myth yearned for treasure to be unearthed that could bolster his efforts. Inspirationally, using ferricyanide (Fe(CN)63-) in an electrolyte as driving force taking advantage fast nucleation rate copper hexacyanoferrate (CuHCF), we successfully reversed Fe Cu typically occurs during cycling....
Abstract Although theoretical studies and experimental investigations have demonstrated the presence of space-charge-induced dopant segregation, most work has been confined largely to crystal-free surface some special grain boundaries, best our knowledge there no systematic comparison understand how segregation varies at different types interfaces in polycrystals. Here, through atomic-column resolved scanning transmission electron microscopy real polycrystalline samples, we directly...
Zn–In bimetallic nanocrystals exhibit excellent selectivity for electrochemical CO<sub>2</sub>reduction to HCOOH, whose efficiency is greatly enhanced with 5% In composition.
Single-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pregrown CdS NWs. They uniformly grown with [100] or [110], [112] direction in a controlled manner. In solvothermal growth, oriented attachment octylamine (OA) ligands enables NWs to be produced morphology growth direction. As concentration OA increases, evolves from higher surface-energy [110] directions under more...
Novel photocatalysts (TiO<sub>2</sub>@TiO<sub>1−x</sub>N<sub>x</sub>) with the core–shell structure, prepared by controlled nitridation of TiO<sub>2</sub> microspheres, show photocatalytic activity under visible-light irradiation.
We report nitrogen-rich 1T′ phase MoS<sub>2</sub> layered nanostructures using different alkyl amines as intercalants, with first-principles calculations.
Development of high-performance catalysts is very crucial for the commercialization sustainable energy conversion technologies. Searching stable, highly active, and low-cost multifunctional has become a critical issue. In this study, we report synthesis IrO2–ZnO hybrid nanoparticles their efficient electrocatalytic activities toward oxygen/hydrogen evolution reaction (OER/HER) as well oxygen reduction (ORR). For comparison, synthesized RuO2–ZnO, showing smaller catalytic activity than...
Raman spectra of single-wall carbon nanotubes (SWNTs) exhibit a unique radial breathing mode (RBM) band (∼100–300 cm–1) and G– peak (∼1570 cm–1), along with D (∼1350 cm–1). We show that the typical signals for SWNTs are signature their helical structure determined using density functional theory simulation structural analysis hydrogenated dehydrogenated SWNT samples. demonstrate at ∼1570 cm–1 is to opened tubular graphene structures ∼2 nm diameter. also ∼1350 originated from edge defects...
We realized the synthesis of carbon nanorods-monodisperse colloidal particles with a length 50 nm and width 20 nm-which can be considered an addition to family light-emitting carbon-based nanostructures. Their anisotropic shape is determined by use surfactant aminopropylisobutyl polyhedral oligomeric silsesquioxane, their optical properties originate from domains polycyclic aromatic hydrocarbons incorporated within inorganic framework. The nanorods show dual polarized emission quantum yield...
Graphitic carbon anodes have long been used in Li ion batteries due to their combination of attractive properties, such as low cost, high gravimetric energy density, and good rate capability. However, one significant challenge is controlling, optimizing, the nature formation solid electrolyte interphase (SEI). Here it demonstrated that coating via chemical vapor deposition (CVD) facilitates electrochemical performance anodes. We examine characterize substrate/vertical graphene interface...
Ag/Pr6O11 catalysts supported by either Pr6O11 nanorods (Pr6O11-NRs) or nanoparticles (Pr6O11-NPs) were prepared conventional incipient wetness impregnation. The nanocomposite of Ag/Pr6O11-NRs demonstrated a higher catalytic activity for CO oxidation than Ag/Pr6O11-NPs at lower temperatures. This improved performance may be ascribed to the mesoporous features and resultant oxygen vacancies support, as well large surface area homogeneous loading Ag species. As result, 98.7 100% conversions...
Abstract The design of crystalline polymers is intellectually stimulating and synthetically challenging, especially when the polymerization any monomer occurs in a linear dimension. Such growth often leads to entropically driven chain entanglements thus detrimental attempts realize full potential conjugated molecular structures. Here we report two-monomer-connected precursors (TMCPs) which two pyrrole units are linked through connector, yielding highly polymers. simultaneous TMCP results...